Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.
Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.
All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)
The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.
Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.
User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)
This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILES
for N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
done
FILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\<event\>/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES
... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.
Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.
( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )
Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove net/genetlink.h inclusion, now sched.c won't be recompiled
because of some networking changes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'current' is a pointer, so the right form is 'down_write(¤t->mm->mmap_sem)'.
Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
debugfs: Modify default debugfs directory for debugging pktcdvd.
debugfs: Modified default dir of debugfs for debugging UHCI.
debugfs: Change debugfs directory of IWMC3200
debugfs: Change debuhgfs directory of trace-events-sample.h
debugfs: Fix mount directory of debugfs by default in events.txt
hpilo: add poll f_op
hpilo: add interrupt handler
hpilo: staging for interrupt handling
driver core: platform_device_add_data(): use kmemdup()
Driver core: Add support for compatibility classes
uio: add generic driver for PCI 2.3 devices
driver-core: move dma-coherent.c from kernel to driver/base
mem_class: fix bug
mem_class: use minor as index instead of searching the array
driver model: constify attribute groups
UIO: remove 'default n' from Kconfig
Driver core: Add accessor for device platform data
Driver core: move dev_get/set_drvdata to drivers/base/dd.c
Driver core: add new device to bus's list before probing
* 'writeback' of git://git.kernel.dk/linux-2.6-block:
writeback: fix possible bdi writeback refcounting problem
writeback: Fix bdi use after free in wb_work_complete()
writeback: improve scalability of bdi writeback work queues
writeback: remove smp_mb(), it's not needed with list_add_tail_rcu()
writeback: use schedule_timeout_interruptible()
writeback: add comments to bdi_work structure
writeback: splice dirty inode entries to default bdi on bdi_destroy()
writeback: separate starting of sync vs opportunistic writeback
writeback: inline allocation failure handling in bdi_alloc_queue_work()
writeback: use RCU to protect bdi_list
writeback: only use bdi_writeback_all() for WB_SYNC_NONE writeout
fs: Assign bdi in super_block
writeback: make wb_writeback() take an argument structure
writeback: merely wakeup flusher thread if work allocation fails for WB_SYNC_NONE
writeback: get rid of wbc->for_writepages
fs: remove bdev->bd_inode_backing_dev_info
We cannot safely ensure that the inodes are all gone at this point
in time, and we must not destroy this bdi with inodes having off it.
So just splice our entries to the default bdi since that one will
always persist.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
bdi_start_writeback() is currently split into two paths, one for
WB_SYNC_NONE and one for WB_SYNC_ALL. Add bdi_sync_writeback()
for WB_SYNC_ALL writeback and let bdi_start_writeback() handle
only WB_SYNC_NONE.
Push down the writeback_control allocation and only accept the
parameters that make sense for each function. This cleans up
the API considerably.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Now that bdi_writeback_all() no longer handles integrity writeback,
it doesn't have to block anymore. This means that we can switch
bdi_list reader side protection to RCU.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Useful for some testing scenarios, although specific testing is often
done better through MADV_POISON
This can be done with the x86 level MCE injector too, but this interface
allows it to do independently from low level x86 changes.
v2: Add module license (Haicheng Li)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Impact: optional, useful for debugging
Add a new madvice sub command to inject poison for some
pages in a process' address space. This is useful for
testing the poison page handling.
This patch can allow root to tie up large amounts of memory.
I got feedback from container developers and they didn't see any
problem.
v2: Use write flag for get_user_pages to make sure to always get
a fresh page
v3: Don't request write mapping (Fengguang Wu)
v4: Move MADV_* number to avoid conflict with KSM (Hugh Dickins)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Enable removing of corrupted pages through truncation
for a bunch of file systems: ext*, xfs, gfs2, ocfs2, ntfs
These should cover most server needs.
I chose the set of migration aware file systems for this
for now, assuming they have been especially audited.
But in general it should be safe for all file systems
on the data area that support read/write and truncate.
Caveat: the hardware error handler does not take i_mutex
for now before calling the truncate function. Is that ok?
Cc: tytso@mit.edu
Cc: hch@infradead.org
Cc: mfasheh@suse.com
Cc: aia21@cantab.net
Cc: hugh.dickins@tiscali.co.uk
Cc: swhiteho@redhat.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Add the high level memory handler that poisons pages
that got corrupted by hardware (typically by a two bit flip in a DIMM
or a cache) on the Linux level. The goal is to prevent everyone
from accessing these pages in the future.
This done at the VM level by marking a page hwpoisoned
and doing the appropriate action based on the type of page
it is.
The code that does this is portable and lives in mm/memory-failure.c
To quote the overview comment:
High level machine check handler. Handles pages reported by the
hardware as being corrupted usually due to a 2bit ECC memory or cache
failure.
This focuses on pages detected as corrupted in the background.
When the current CPU tries to consume corruption the currently
running process can just be killed directly instead. This implies
that if the error cannot be handled for some reason it's safe to
just ignore it because no corruption has been consumed yet. Instead
when that happens another machine check will happen.
Handles page cache pages in various states. The tricky part
here is that we can access any page asynchronous to other VM
users, because memory failures could happen anytime and anywhere,
possibly violating some of their assumptions. This is why this code
has to be extremely careful. Generally it tries to use normal locking
rules, as in get the standard locks, even if that means the
error handling takes potentially a long time.
Some of the operations here are somewhat inefficient and have non
linear algorithmic complexity, because the data structures have not
been optimized for this case. This is in particular the case
for the mapping from a vma to a process. Since this case is expected
to be rare we hope we can get away with this.
There are in principle two strategies to kill processes on poison:
- just unmap the data and wait for an actual reference before
killing
- kill as soon as corruption is detected.
Both have advantages and disadvantages and should be used
in different situations. Right now both are implemented and can
be switched with a new sysctl vm.memory_failure_early_kill
The default is early kill.
The patch does some rmap data structure walking on its own to collect
processes to kill. This is unusual because normally all rmap data structure
knowledge is in rmap.c only. I put it here for now to keep
everything together and rmap knowledge has been seeping out anyways
Includes contributions from Johannes Weiner, Chris Mason, Fengguang Wu,
Nick Piggin (who did a lot of great work) and others.
Cc: npiggin@suse.de
Cc: riel@redhat.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
The dirtying of page and set_page_dirty() can be moved into the page lock.
- In shmem_write_end(), the page was dirtied while the page lock was held,
but it's being marked dirty just after dropping the page lock.
- In shmem_symlink(), both dirtying and marking can be moved into page lock.
It's valuable for the hwpoison code to know whether one bad page can be dropped
without losing data. It mainly judges by testing the PG_dirty bit after taking
the page lock. So it becomes important that the dirtying of page and the
marking of dirtiness are both done inside the page lock. Which is a common
practice, but sadly not a rule.
The noticeable exceptions are
- mapped pages
- pages with buffer_heads
The above pages could go dirty at any time. Fortunately the hwpoison will
unmap the page and release the buffer_heads beforehand anyway.
Many other types of pages (eg. metadata pages) can also be dirtied at will by
their owners, the hwpoison code cannot do meaningful things to them anyway.
Only the dirtiness of pagecache pages owned by regular files are interested.
v2: AK: Add comment about set_page_dirty rules (suggested by Peter Zijlstra)
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Truncating metadata pages is not safe right now before
we haven't audited all file systems.
To enable truncation only for data address space define
a new address_space callback error_remove_page.
This is used for memory_failure.c memory error handling.
This can be then set to truncate_inode_page()
This patch just defines the new operation and adds documentation.
Callers and users come in followon patches.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Add a simple way to invalidate a single page
This is just a refactoring of the truncate.c code.
Originally from Fengguang, modified by Andi Kleen.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Extract out truncate_inode_page() out of the truncate path so that
it can be used by memory-failure.c
[AK: description, headers, fix typos]
v2: Some white space changes from Fengguang Wu
Signed-off-by: Andi Kleen <ak@linux.intel.com>
If memory corruption hits the free buddy pages, we can safely ignore them.
No one will access them until page allocation time, then prep_new_page()
will automatically check and isolate PG_hwpoison page for us (for 0-order
allocation).
This patch expands prep_new_page() to check every component page in a high
order page allocation, in order to completely stop PG_hwpoison pages from
being recirculated.
Note that the common case -- only allocating a single page, doesn't
do any more work than before. Allocating > order 0 does a bit more work,
but that's relatively uncommon.
This simple implementation may drop some innocent neighbor pages, hopefully
it is not a big problem because the event should be rare enough.
This patch adds some runtime costs to high order page users.
[AK: Improved description]
v2: Andi Kleen:
Port to -mm code
Move check into separate function.
Don't dump stack in bad_pages for hwpoisoned pages.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
When a page has the poison bit set replace the PTE with a poison entry.
This causes the right error handling to be done later when a process runs
into it.
v2: add a new flag to not do that (needed for the memory-failure handler
later) (Fengguang)
v3: remove unnecessary is_migration_entry() test (Fengguang, Minchan)
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
try_to_unmap currently has multiple modi (migration, munlock, normal unmap)
which are selected by magic flag variables. The logic is not very straight
forward, because each of these flag change multiple behaviours (e.g.
migration turns off aging, not only sets up migration ptes etc.)
Also the different flags interact in magic ways.
A later patch in this series adds another mode to try_to_unmap, so
this becomes quickly unmanageable.
Replace the different flags with a action code (migration, munlock, munmap)
and some additional flags as modifiers (ignore mlock, ignore aging).
This makes the logic more straight forward and allows easier extension
to new behaviours. Change all the caller to declare what they want to
do.
This patch is supposed to be a nop in behaviour. If anyone can prove
it is not that would be a bug.
Cc: Lee.Schermerhorn@hp.com
Cc: npiggin@suse.de
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Bail out early when hardware poisoned pages are found in page fault handling.
Since they are poisoned they should not be mapped freshly into processes,
because that would cause another (potentially deadly) machine check
This is generally handled in the same way as OOM, just a different
error code is returned to the architecture code.
v2: Do a page unlock if needed (Fengguang Wu)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
- Add a new VM_FAULT_HWPOISON error code to handle_mm_fault. Right now
architectures have to explicitely enable poison page support, so
this is forward compatible to all architectures. They only need
to add it when they enable poison page support.
- Add poison page handling in swap in fault code
v2: Add missing delayacct_clear_flag (Hidehiro Kawai)
v3: Really use delayacct_clear_flag (Hidehiro Kawai)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Memory migration uses special swap entry types to trigger special actions on
page faults. Extend this mechanism to also support poisoned swap entries, to
trigger poison handling on page faults. This allows follow-on patches to
prevent processes from faulting in poisoned pages again.
v2: Fix overflow in MAX_SWAPFILES (Fengguang Wu)
v3: Better overflow fix (Hidehiro Kawai)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Needed for later patch that walks rmap entries on its own.
This used to be very frowned upon, but memory-failure.c does
some rather specialized rmap walking and rmap has been stable
for quite some time, so I think it's ok now to export it.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
This build bug:
mm/slub.c: In function 'kmem_cache_open':
mm/slub.c:2476: error: 'disable_higher_order_debug' undeclared (first use in this function)
mm/slub.c:2476: error: (Each undeclared identifier is reported only once
mm/slub.c:2476: error: for each function it appears in.)
Triggers because there's no !CONFIG_SLUB_DEBUG definition for
disable_higher_order_debug.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.
Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.
If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.
If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.
It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Tested-By: Harald Hoyer <harald@redhat.com>
Tested-By: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
powerpc64: convert to dynamic percpu allocator
sparc64: use embedding percpu first chunk allocator
percpu: kill lpage first chunk allocator
x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
percpu: update embedding first chunk allocator to handle sparse units
percpu: use group information to allocate vmap areas sparsely
vmalloc: implement pcpu_get_vm_areas()
vmalloc: separate out insert_vmalloc_vm()
percpu: add chunk->base_addr
percpu: add pcpu_unit_offsets[]
percpu: introduce pcpu_alloc_info and pcpu_group_info
percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
percpu: add @align to pcpu_fc_alloc_fn_t
percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
percpu: drop @static_size from first chunk allocators
percpu: generalize first chunk allocator selection
percpu: build first chunk allocators selectively
percpu: rename 4k first chunk allocator to page
percpu: improve boot messages
percpu: fix pcpu_reclaim() locking
...
Fix trivial conflict as by Tejun Heo in kernel/sched.c
* 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, pat: Fix cacheflush address in change_page_attr_set_clr()
mm: remove !NUMA condition from PAGEFLAGS_EXTENDED condition set
x86: Fix earlyprintk=dbgp for machines without NX
x86, pat: Sanity check remap_pfn_range for RAM region
x86, pat: Lookup the protection from memtype list on vm_insert_pfn()
x86, pat: Add lookup_memtype to get the current memtype of a paddr
x86, pat: Use page flags to track memtypes of RAM pages
x86, pat: Generalize the use of page flag PG_uncached
x86, pat: Add rbtree to do quick lookup in memtype tracking
x86, pat: Add PAT reserve free to io_mapping* APIs
x86, pat: New i/f for driver to request memtype for IO regions
x86, pat: ioremap to follow same PAT restrictions as other PAT users
x86, pat: Keep identity maps consistent with mmaps even when pat_disabled
x86, mtrr: make mtrr_aps_delayed_init static bool
x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init
generic-ipi: Allow cpus not yet online to call smp_call_function with irqs disabled
x86: Fix an incorrect argument of reserve_bootmem()
x86: Fix system crash when loading with "reservetop" parameter
* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits)
block: use blkdev_issue_discard in blk_ioctl_discard
Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads
block: don't assume device has a request list backing in nr_requests store
block: Optimal I/O limit wrapper
cfq: choose a new next_req when a request is dispatched
Seperate read and write statistics of in_flight requests
aoe: end barrier bios with EOPNOTSUPP
block: trace bio queueing trial only when it occurs
block: enable rq CPU completion affinity by default
cfq: fix the log message after dispatched a request
block: use printk_once
cciss: memory leak in cciss_init_one()
splice: update mtime and atime on files
block: make blk_iopoll_prep_sched() follow normal 0/1 return convention
cfq-iosched: get rid of must_alloc flag
block: use interrupts disabled version of raise_softirq_irqoff()
block: fix comment in blk-iopoll.c
block: adjust default budget for blk-iopoll
block: fix long lines in block/blk-iopoll.c
block: add blk-iopoll, a NAPI like approach for block devices
...
* 'kvm-updates/2.6.32' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (202 commits)
MAINTAINERS: update KVM entry
KVM: correct error-handling code
KVM: fix compile warnings on s390
KVM: VMX: Check cpl before emulating debug register access
KVM: fix misreporting of coalesced interrupts by kvm tracer
KVM: x86: drop duplicate kvm_flush_remote_tlb calls
KVM: VMX: call vmx_load_host_state() only if msr is cached
KVM: VMX: Conditionally reload debug register 6
KVM: Use thread debug register storage instead of kvm specific data
KVM guest: do not batch pte updates from interrupt context
KVM: Fix coalesced interrupt reporting in IOAPIC
KVM guest: fix bogus wallclock physical address calculation
KVM: VMX: Fix cr8 exiting control clobbering by EPT
KVM: Optimize kvm_mmu_unprotect_page_virt() for tdp
KVM: Document KVM_CAP_IRQCHIP
KVM: Protect update_cr8_intercept() when running without an apic
KVM: VMX: Fix EPT with WP bit change during paging
KVM: Use kvm_{read,write}_guest_virt() to read and write segment descriptors
KVM: x86 emulator: Add adc and sbb missing decoder flags
KVM: Add missing #include
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
slub: fix slab_pad_check()
slub: release kobject if sysfs_create_group failed in sysfs_slab_add
SLUB: fix ARCH_KMALLOC_MINALIGN cases 64 and 256
SLUB: Fix some coding style issues
SLUB: Drop write permission to /proc/slabinfo
slab: remove duplicate kmem_cache_init_late() declarations
slub: change kmem_cache->align to record the real alignment
slub: use size and objsize orders to disable debug flags
slub: add option to disable higher order debugging slabs
Introduce new function for generic inode syncing (vfs_fsync_range) and use
it from fsync() path. Introduce also new helper for syncing after a sync
write (generic_write_sync) using the generic function.
Use these new helpers for syncing from generic VFS functions. This makes
O_SYNC writes to block devices acquire i_mutex for syncing. If we really
care about this, we can make block_fsync() drop the i_mutex and reacquire
it before it returns.
CC: Evgeniy Polyakov <zbr@ioremap.net>
CC: ocfs2-devel@oss.oracle.com
CC: Joel Becker <joel.becker@oracle.com>
CC: Felix Blyakher <felixb@sgi.com>
CC: xfs@oss.sgi.com
CC: Anton Altaparmakov <aia21@cantab.net>
CC: linux-ntfs-dev@lists.sourceforge.net
CC: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
CC: linux-ext4@vger.kernel.org
CC: tytso@mit.edu
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
generic_file_aio_write_nolock() is now used only by block devices and raw
character device. Filesystems should use __generic_file_aio_write() in case
generic_file_aio_write() doesn't suit them. So rename the function to
blkdev_aio_write() and move it to fs/blockdev.c.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
generic_file_direct_write() and generic_file_buffered_write() called
generic_osync_inode() if it was called on O_SYNC file or IS_SYNC inode. But
this is superfluous since generic_file_aio_write() does the syncing as well.
Also XFS and OCFS2 which call these functions directly handle syncing
themselves. So let's have a single place where syncing happens:
generic_file_aio_write().
We slightly change the behavior by syncing only the range of file to which the
write happened for buffered writes but that should be all that is required.
CC: ocfs2-devel@oss.oracle.com
CC: Joel Becker <joel.becker@oracle.com>
CC: Felix Blyakher <felixb@sgi.com>
CC: xfs@oss.sgi.com
Signed-off-by: Jan Kara <jack@suse.cz>
Rename __generic_file_aio_write_nolock() to __generic_file_aio_write(), add
comments to write helpers explaining how they should be used and export
__generic_file_aio_write() since it will be used by some filesystems.
CC: ocfs2-devel@oss.oracle.com
CC: Joel Becker <joel.becker@oracle.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
This simple helper saves some filesystems conversion from byte offset
to page numbers and also makes the fdata* interface more complete.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
blk_ioctl_discard duplicates large amounts of code from blkdev_issue_discard,
the only difference between the two is that blkdev_issue_discard needs to
send a barrier discard request and blk_ioctl_discard a non-barrier one,
and blk_ioctl_discard needs to wait on the request. To facilitates this
add a flags argument to blkdev_issue_discard to control both aspects of the
behaviour. This will be very useful later on for using the waiting
funcitonality for other callers.
Based on an earlier patch from Matthew Wilcox <matthew@wil.cx>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
When SLAB_POISON is used and slab_pad_check() finds an overwrite of the
slab padding, we call restore_bytes() on the whole slab, not only
on the padding.
Acked-by: Christoph Lameer <cl@linux-foundation.org>
Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
* 'writeback' of git://git.kernel.dk/linux-2.6-block:
writeback: check for registered bdi in flusher add and inode dirty
writeback: add name to backing_dev_info
writeback: add some debug inode list counters to bdi stats
writeback: get rid of pdflush completely
writeback: switch to per-bdi threads for flushing data
writeback: move dirty inodes from super_block to backing_dev_info
writeback: get rid of generic_sync_sb_inodes() export
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: Improve the "Early log buffer exceeded" error message
kmemleak: fix sparse warning for static declarations
kmemleak: fix sparse warning over overshadowed flags
kmemleak: move common painting code together
kmemleak: add clear command support
kmemleak: use bool for true/false questions
kmemleak: Do no create the clean-up thread during kmemleak_disable()
kmemleak: Scan all thread stacks
kmemleak: Don't scan uninitialized memory when kmemcheck is enabled
kmemleak: Ignore the aperture memory hole on x86_64
kmemleak: Printing of the objects hex dump
kmemleak: Do not report alloc_bootmem blocks as leaks
kmemleak: Save the stack trace for early allocations
kmemleak: Mark the early log buffer as __initdata
kmemleak: Dump object information on request
kmemleak: Allow rescheduling during an object scanning
Based on a suggestion from Jaswinder, clarify what the user would need
to do to avoid this error message from kmemleak.
Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Also a debugging aid. We want to catch dirty inodes being added to
backing devices that don't do writeback.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This enables us to track who does what and print info. Its main use
is catching dirty inodes on the default_backing_dev_info, so we can
fix that up.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This gets rid of pdflush for bdi writeout and kupdated style cleaning.
pdflush writeout suffers from lack of locality and also requires more
threads to handle the same workload, since it has to work in a
non-blocking fashion against each queue. This also introduces lumpy
behaviour and potential request starvation, since pdflush can be starved
for queue access if others are accessing it. A sample ffsb workload that
does random writes to files is about 8% faster here on a simple SATA drive
during the benchmark phase. File layout also seems a LOT more smooth in
vmstat:
r b swpd free buff cache si so bi bo in cs us sy id wa
0 1 0 608848 2652 375372 0 0 0 71024 604 24 1 10 48 42
0 1 0 549644 2712 433736 0 0 0 60692 505 27 1 8 48 44
1 0 0 476928 2784 505192 0 0 4 29540 553 24 0 9 53 37
0 1 0 457972 2808 524008 0 0 0 54876 331 16 0 4 38 58
0 1 0 366128 2928 614284 0 0 4 92168 710 58 0 13 53 34
0 1 0 295092 3000 684140 0 0 0 62924 572 23 0 9 53 37
0 1 0 236592 3064 741704 0 0 4 58256 523 17 0 8 48 44
0 1 0 165608 3132 811464 0 0 0 57460 560 21 0 8 54 38
0 1 0 102952 3200 873164 0 0 4 74748 540 29 1 10 48 41
0 1 0 48604 3252 926472 0 0 0 53248 469 29 0 7 47 45
where vanilla tends to fluctuate a lot in the creation phase:
r b swpd free buff cache si so bi bo in cs us sy id wa
1 1 0 678716 5792 303380 0 0 0 74064 565 50 1 11 52 36
1 0 0 662488 5864 319396 0 0 4 352 302 329 0 2 47 51
0 1 0 599312 5924 381468 0 0 0 78164 516 55 0 9 51 40
0 1 0 519952 6008 459516 0 0 4 78156 622 56 1 11 52 37
1 1 0 436640 6092 541632 0 0 0 82244 622 54 0 11 48 41
0 1 0 436640 6092 541660 0 0 0 8 152 39 0 0 51 49
0 1 0 332224 6200 644252 0 0 4 102800 728 46 1 13 49 36
1 0 0 274492 6260 701056 0 0 4 12328 459 49 0 7 50 43
0 1 0 211220 6324 763356 0 0 0 106940 515 37 1 10 51 39
1 0 0 160412 6376 813468 0 0 0 8224 415 43 0 6 49 45
1 1 0 85980 6452 886556 0 0 4 113516 575 39 1 11 54 34
0 2 0 85968 6452 886620 0 0 0 1640 158 211 0 0 46 54
A 10 disk test with btrfs performs 26% faster with per-bdi flushing. A
SSD based writeback test on XFS performs over 20% better as well, with
the throughput being very stable around 1GB/sec, where pdflush only
manages 750MB/sec and fluctuates wildly while doing so. Random buffered
writes to many files behave a lot better as well, as does random mmap'ed
writes.
A separate thread is added to sync the super blocks. In the long term,
adding sync_supers_bdi() functionality could get rid of this thread again.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is a first step at introducing per-bdi flusher threads. We should
have no change in behaviour, although sb_has_dirty_inodes() is now
ridiculously expensive, as there's no easy way to answer that question.
Not a huge problem, since it'll be deleted in subsequent patches.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
shmfs wants purely standard POSIX ACL semantics, so we can use the new
generic VFS layer POSIX ACL checking rather than cooking our own
'permission()' function.
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes these sparse warnings:
mm/kmemleak.c:1179:6: warning: symbol 'start_scan_thread' was not declared. Should it be static?
mm/kmemleak.c:1194:6: warning: symbol 'stop_scan_thread' was not declared. Should it be static?
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
A secondary irq_save is not required as a locking before it was
already disabling irqs.
This fixes this sparse warning:
mm/kmemleak.c:512:31: warning: symbol 'flags' shadows an earlier one
mm/kmemleak.c:448:23: originally declared here
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When painting grey or black we do the same thing, bring
this together into a helper and identify coloring grey or
black explicitly with defines. This makes this a little
easier to read.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In an ideal world your kmemleak output will be small, when its
not (usually during initial bootup) you can use the clear command
to ingore previously reported and unreferenced kmemleak objects. We
do this by painting all currently reported unreferenced objects grey.
We paint them grey instead of black to allow future scans on the same
objects as such objects could still potentially reference newly
allocated objects in the future.
To test a critical section on demand with a clean
/sys/kernel/debug/kmemleak you can do:
echo clear > /sys/kernel/debug/kmemleak
test your kernel or modules
echo scan > /sys/kernel/debug/kmemleak
Then as usual to get your report with:
cat /sys/kernel/debug/kmemleak
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The kmemleak_disable() function could be called from various contexts
including IRQ. It creates a clean-up thread but the kthread_create()
function has restrictions on which contexts it can be called from,
mainly because of the kthread_create_lock. The patch changes the
kmemleak clean-up thread to a workqueue.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Eric Paris <eparis@redhat.com>
On low-memory systems, anti-fragmentation gets disabled as fragmentation
cannot be avoided on a sufficiently large boundary to be worthwhile. Once
disabled, there is a period of time when all the pageblocks are marked
MOVABLE and the expectation is that they get marked UNMOVABLE at each call
to __rmqueue_fallback().
However, when MAX_ORDER is large the pageblocks do not change ownership
because the normal criteria are not met. This has the effect of
prematurely breaking up too many large contiguous blocks. This is most
serious on NOMMU systems which depend on high-order allocations to boot.
This patch causes pageblocks to change ownership on every fallback when
anti-fragmentation is disabled. This prevents the large blocks being
prematurely broken up.
This is a fix to commit 49255c619f [page
allocator: move check for disabled anti-fragmentation out of fastpath] and
the problem affects 2.6.31-rc8.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the error handling in do_mmap_pgoff(). If do_mmap_shared_file() or
do_mmap_private() fail, we jump to the error_put_region label at which
point we cann __put_nommu_region() on the region - but we haven't yet
added the region to the tree, and so __put_nommu_region() may BUG
because the region tree is empty or it may corrupt the region tree.
To get around this, we can afford to add the region to the region tree
before calling do_mmap_shared_file() or do_mmap_private() as we keep
nommu_region_sem write-locked, so no-one can race with us by seeing a
transient region.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch changes the for_each_process() loop with the
do_each_thread()/while_each_thread() pair.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ingo Molnar reported the following kmemcheck warning when running both
kmemleak and kmemcheck enabled:
PM: Adding info for No Bus:vcsa7
WARNING: kmemcheck: Caught 32-bit read from uninitialized memory
(f6f6e1a4)
d873f9f600000000c42ae4c1005c87f70000000070665f666978656400000000
i i i i u u u u i i i i i i i i i i i i i i i i i i i i i u u u
^
Pid: 3091, comm: kmemleak Not tainted (2.6.31-rc7-tip #1303) P4DC6
EIP: 0060:[<c110301f>] EFLAGS: 00010006 CPU: 0
EIP is at scan_block+0x3f/0xe0
EAX: f40bd700 EBX: f40bd780 ECX: f16b46c0 EDX: 00000001
ESI: f6f6e1a4 EDI: 00000000 EBP: f10f3f4c ESP: c2605fcc
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: e89a4844 CR3: 30ff1000 CR4: 000006f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff4ff0 DR7: 00000400
[<c110313c>] scan_object+0x7c/0xf0
[<c1103389>] kmemleak_scan+0x1d9/0x400
[<c1103a3c>] kmemleak_scan_thread+0x4c/0xb0
[<c10819d4>] kthread+0x74/0x80
[<c10257db>] kernel_thread_helper+0x7/0x3c
[<ffffffff>] 0xffffffff
kmemleak: 515 new suspected memory leaks (see
/sys/kernel/debug/kmemleak)
kmemleak: 42 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
The problem here is that kmemleak will scan partially initialized
objects that makes kmemcheck complain. Fix that up by skipping
uninitialized memory regions when kmemcheck is enabled.
Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
kmem_cache_destroy() should call rcu_barrier() *after* kmem_cache_close() and
*before* sysfs_slab_remove() or risk rcu_free_slab() being called after
kmem_cache is deleted (kfreed).
rmmod nf_conntrack can crash the machine because it has to kmem_cache_destroy()
a SLAB_DESTROY_BY_RCU enabled cache.
Cc: <stable@kernel.org>
Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
When CONFIG_SLUB_DEBUG is enabled, sysfs_slab_add should unlink and put the
kobject if sysfs_create_group failed. Otherwise, sysfs_slab_add returns error
then free kmem_cache s, thus memory of s->kobj is leaked.
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
percpu incorrectly assumed that cpu0 was always there which led to the
following warning and eventual oops on sparc machines w/o cpu0.
WARNING: at mm/percpu.c:651 pcpu_map+0xdc/0x100()
Modules linked in:
Call Trace:
[000000000045eb70] warn_slowpath_common+0x50/0xa0
[000000000045ebdc] warn_slowpath_null+0x1c/0x40
[00000000004d493c] pcpu_map+0xdc/0x100
[00000000004d59a4] pcpu_alloc+0x3e4/0x4e0
[00000000004d5af8] __alloc_percpu+0x18/0x40
[00000000005b112c] __percpu_counter_init+0x4c/0xc0
...
Unable to handle kernel NULL pointer dereference
...
I7: <sysfs_new_dirent+0x30/0x120>
Disabling lock debugging due to kernel taint
Caller[000000000053c1b0]: sysfs_new_dirent+0x30/0x120
Caller[000000000053c7a4]: create_dir+0x24/0xc0
Caller[000000000053c870]: sysfs_create_dir+0x30/0x80
Caller[00000000005990e8]: kobject_add_internal+0xc8/0x200
...
Kernel panic - not syncing: Attempted to kill the idle task!
This patch fixes the problem by backporting parts from devel branch to
make percpu core not depend on the existence of cpu0.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Meelis Roos <mroos@linux.ee>
Cc: David Miller <davem@davemloft.net>
CONFIG_PAGEFLAGS_EXTENDED disables a trick to conserve pageflags.
This trick is indended to be enabled when the pressure on page flags
is very high.
The previous condition was:
- depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM
... however, the sparsemem code already has a way to crowd out the
node number from the pageflags, which means that !NUMA actually
doesn't contribute to hard pageflags exhaustion.
This is required for the new PG_uncached flag to not cause pageflags
exhaustion on x86_32 + PAE + SPARSEMEM + !NUMA.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4A9828F4.4040905@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.siddha@intel.com>
If the minalign is 64 bytes, then the 96 byte cache should not be created
because it would conflict with the 128 byte cache.
If the minalign is 256 bytes, patching the size_index table should not
result in a buffer overrun.
The calculation "(i - 1) / 8" used to access size_index[] is moved to
a separate function as suggested by Christoph Lameter.
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Introducing printing of the objects hex dump to the seq file.
The number of lines to be printed is limited to HEX_MAX_LINES
to prevent seq file spamming. The actual number of printed
bytes is less than or equal to (HEX_MAX_LINES * HEX_ROW_SIZE).
(slight adjustments by Catalin Marinas)
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch sets the min_count for alloc_bootmem objects to 0 so that
they are never reported as leaks. This is because many of these blocks
are only referred via the physical address which is not looked up by
kmemleak.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Before slab is initialised, kmemleak save the allocations in an early
log buffer. They are later recorded as normal memory allocations. This
patch adds the stack trace saving to the early log buffer, otherwise the
information shown for such objects only refers to the kmemleak_init()
function.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This buffer isn't needed after kmemleak was initialised so it can be
freed together with the .init.data section. This patch also marks
functions conditionally accessing the early log variables with __ref.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
By writing dump=<addr> to the kmemleak file, kmemleak will look up an
object with that address and dump the information it has about it to
syslog. This is useful in debugging memory leaks.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
If the object size is bigger than a predefined value (4K in this case),
release the object lock during scanning and call cond_resched().
Re-acquire the lock after rescheduling and test whether the object is
still valid.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
An mlocked page might lose the isolatation race. This causes the page to
clear PG_mlocked while it remains in a VM_LOCKED vma. This means it can
be put onto the [in]active list. We can rescue it by using try_to_unmap()
in shrink_page_list().
But now, As Wu Fengguang pointed out, vmscan has a bug. If the page has
PG_referenced, it can't reach try_to_unmap() in shrink_page_list() but is
put into the active list. If the page is referenced repeatedly, it can
remain on the [in]active list without being moving to the unevictable
list.
This patch fixes it.
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <<kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: use the right flag for get_vm_area()
percpu, sparc64: fix sparse possible cpu map handling
init: set nr_cpu_ids before setup_per_cpu_areas()
If node_load[] is cleared everytime build_zonelists() is
called,node_load[] will have no help to find the next node that should
appear in the given node's fallback list.
Because of the bug, zonelist's node_order is not calculated as expected.
This bug affects on big machine, which has asynmetric node distance.
[synmetric NUMA's node distance]
0 1 2
0 10 12 12
1 12 10 12
2 12 12 10
[asynmetric NUMA's node distance]
0 1 2
0 10 12 20
1 12 10 14
2 20 14 10
This (my bug) is very old but no one has reported this for a long time.
Maybe because the number of asynmetric NUMA is very small and they use
cpuset for customizing node memory allocation fallback.
[akpm@linux-foundation.org: fix CONFIG_NUMA=n build]
Signed-off-by: Bo Liu <bo-liu@hotmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
According to the POSIX (1003.1-2008), the file descriptor shall have been
opened with read permission, regardless of the protection options specified to
mmap(). The ltp test cases mmap06/07 need this.
Signed-off-by: Graff Yang <graff.yang@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to
the mm_struct. It was a very good first step for sanitize OOM.
However Paul Menage reported the commit makes regression to his job
scheduler. Current OOM logic can kill OOM_DISABLED process.
Why? His program has the code of similar to the following.
...
set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */
...
if (vfork() == 0) {
set_oom_adj(0); /* Invoked child can be killed */
execve("foo-bar-cmd");
}
....
vfork() parent and child are shared the same mm_struct. then above
set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also
change oom_adj for vfork() parent. Then, vfork() parent (job scheduler)
lost OOM immune and it was killed.
Actually, fork-setting-exec idiom is very frequently used in userland program.
We must not break this assumption.
Then, this patch revert commit 2ff05b2b and related commit.
Reverted commit list
---------------------
- commit 2ff05b2b4e (oom: move oom_adj value from task_struct to mm_struct)
- commit 4d8b9135c3 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE)
- commit 8123681022 (oom: only oom kill exiting tasks with attached memory)
- commit 933b787b57 (mm: copy over oom_adj value at fork time)
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLUB does not support writes to /proc/slabinfo so there should not be write
permission to do that either.
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Currently SELinux enforcement of controls on the ability to map low memory
is determined by the mmap_min_addr tunable. This patch causes SELinux to
ignore the tunable and instead use a seperate Kconfig option specific to how
much space the LSM should protect.
The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
permissions will always protect the amount of low memory designated by
CONFIG_LSM_MMAP_MIN_ADDR.
This allows users who need to disable the mmap_min_addr controls (usual reason
being they run WINE as a non-root user) to do so and still have SELinux
controls preventing confined domains (like a web server) from being able to
map some area of low memory.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
With x86 converted to embedding allocator, lpage doesn't have any user
left. Kill it along with cpa handling code.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Now that percpu core can handle very sparse units, given that vmalloc
space is large enough, embedding first chunk allocator can use any
memory to build the first chunk. This patch teaches
pcpu_embed_first_chunk() about distances between cpus and to use
alloc/free callbacks to allocate node specific areas for each group
and use them for the first chunk.
This brings the benefits of embedding allocator to NUMA configurations
- no extra TLB pressure with the flexibility of unified dynamic
allocator and no need to restructure arch code to build memory layout
suitable for percpu. With units put into atom_size aligned groups
according to cpu distances, using large page for dynamic chunks is
also easily possible with falling back to reuglar pages if large
allocation fails.
Embedding allocator users are converted to specify NULL
cpu_distance_fn, so this patch doesn't cause any visible behavior
difference. Following patches will convert them.
Signed-off-by: Tejun Heo <tj@kernel.org>
ai->groups[] contains which units need to be put consecutively and at
what offset from the chunk base address. Compile this information
into pcpu_group_offsets[] and pcpu_group_sizes[] in
pcpu_setup_first_chunk() and use them to allocate sparse vm areas
using pcpu_get_vm_areas().
This will be used to allow directly using sparse NUMA memories as
percpu areas.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
To directly use spread NUMA memories for percpu units, percpu
allocator will be updated to allow sparsely mapping units in a chunk.
As the distances between units can be very large, this makes
allocating single vmap area for each chunk undesirable. This patch
implements pcpu_get_vm_areas() and pcpu_free_vm_areas() which
allocates and frees sparse congruent vmap areas.
pcpu_get_vm_areas() take @offsets and @sizes array which define
distances and sizes of vmap areas. It scans down from the top of
vmalloc area looking for the top-most address which can accomodate all
the areas. The top-down scan is to avoid interacting with regular
vmallocs which can push up these congruent areas up little by little
ending up wasting address space and page table.
To speed up top-down scan, the highest possible address hint is
maintained. Although the scan is linear from the hint, given the
usual large holes between memory addresses between NUMA nodes, the
scanning is highly likely to finish after finding the first hole for
the last unit which is scanned first.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
Separate out insert_vmalloc_vm() from __get_vm_area_node().
insert_vmalloc_vm() initializes vm_struct from vmap_area and inserts
it into vmlist. insert_vmalloc_vm() only initializes fields which can
be determined from @vm, @flags and @caller The rest should be
initialized by the caller. For __get_vm_area_node(), all other fields
just need to be cleared and this is done by using kzalloc instead of
kmalloc.
This will be used to implement pcpu_get_vm_areas().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
The only thing percpu allocator wants to know about a vmalloc area is
the base address. Instead of requiring chunk->vm, add
chunk->base_addr which contains the necessary value. This simplifies
the code a bit and makes the dummy first_vm unnecessary. This change
will ease allowing a chunk to be mapped by multiple vms.
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently units are mapped sequentially into address space. This
patch adds pcpu_unit_offsets[] which allows units to be mapped to
arbitrary offsets from the chunk base address. This is necessary to
allow sparse embedding which might would need to allocate address
ranges and memory areas which aren't aligned to unit size but
allocation atom size (page or large page size). This also simplifies
things a bit by removing the need to calculate offset from unit
number.
With this change, there's no need for the arch code to know
pcpu_unit_size. Update pcpu_setup_first_chunk() and first chunk
allocators to return regular 0 or -errno return code instead of unit
size or -errno.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Till now, non-linear cpu->unit map was expressed using an integer
array which maps each cpu to a unit and used only by lpage allocator.
Although how many units have been placed in a single contiguos area
(group) is known while building unit_map, the information is lost when
the result is recorded into the unit_map array. For lpage allocator,
as all allocations are done by lpages and whether two adjacent lpages
are in the same group or not is irrelevant, this didn't cause any
problem. Non-linear cpu->unit mapping will be used for sparse
embedding and this grouping information is necessary for that.
This patch introduces pcpu_alloc_info which contains all the
information necessary for initializing percpu allocator.
pcpu_alloc_info contains array of pcpu_group_info which describes how
units are grouped and mapped to cpus. pcpu_group_info also has
base_offset field to specify its offset from the chunk's base address.
pcpu_build_alloc_info() initializes this field as if all groups are
allocated back-to-back as is currently done but this will be used to
sparsely place groups.
pcpu_alloc_info is a rather complex data structure which contains a
flexible array which in turn points to nested cpu_map arrays.
* pcpu_alloc_alloc_info() and pcpu_free_alloc_info() are provided to
help dealing with pcpu_alloc_info.
* pcpu_lpage_build_unit_map() is updated to build pcpu_alloc_info,
generalized and renamed to pcpu_build_alloc_info().
@cpu_distance_fn may be NULL indicating that all cpus are of
LOCAL_DISTANCE.
* pcpul_lpage_dump_cfg() is updated to process pcpu_alloc_info,
generalized and renamed to pcpu_dump_alloc_info(). It now also
prints which group each alloc unit belongs to.
* pcpu_setup_first_chunk() now takes pcpu_alloc_info instead of the
separate parameters. All first chunk allocators are updated to use
pcpu_build_alloc_info() to build alloc_info and call
pcpu_setup_first_chunk() with it. This has the side effect of
packing units for sparse possible cpus. ie. if cpus 0, 2 and 4 are
possible, they'll be assigned unit 0, 1 and 2 instead of 0, 2 and 4.
* x86 setup_pcpu_lpage() is updated to deal with alloc_info.
* sparc64 setup_per_cpu_areas() is updated to build alloc_info.
Although the changes made by this patch are pretty pervasive, it
doesn't cause any behavior difference other than packing of sparse
cpus. It mostly changes how information is passed among
initialization functions and makes room for more flexibility.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Unit map handling will be generalized and extended and used for
embedding sparse first chunk and other purposes. Relocate two
unit_map related functions upward in preparation. This patch just
moves the code without any actual change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that all actual first chunk allocation and copying happen in the
first chunk allocators and helpers, there's no reason for
pcpu_setup_first_chunk() to try to determine @dyn_size automatically.
The only left user is page first chunk allocator. Make it determine
dyn_size like other allocators and make @dyn_size mandatory for
pcpu_setup_first_chunk().
Signed-off-by: Tejun Heo <tj@kernel.org>
First chunk allocators assume percpu areas have been linked using one
of PERCPU_*() macros and depend on __per_cpu_load symbol defined by
those macros, so there isn't much point in passing in static area size
explicitly when it can be easily calculated from __per_cpu_start and
__per_cpu_end. Drop @static_size from all percpu first chunk
allocators and helpers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that all first chunk allocators are in mm/percpu.c, it makes sense
to make generalize percpu_alloc kernel parameter. Define PCPU_FC_*
and set pcpu_chosen_fc using early_param() in mm/percpu.c. Arch code
can use the set value to determine which first chunk allocator to use.
Signed-off-by: Tejun Heo <tj@kernel.org>
There's no need to build unused first chunk allocators in. Define
CONFIG_NEED_PER_CPU_*_FIRST_CHUNK and let archs enable them
selectively.
Signed-off-by: Tejun Heo <tj@kernel.org>
Page size isn't always 4k depending on arch and configuration. Rename
4k first chunk allocator to page.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Improve percpu boot messages such that they're uniform and contain
more information.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
pcpu_reclaim() calls pcpu_depopulate_chunk() which makes use of pages
array and bitmap returned by pcpu_get_pages_and_bitmap() and thus
should be called under pcpu_alloc_mutex. pcpu_reclaim() released the
mutex before calling depopulate leading to double free and other
strange problems caused by the unexpected concurrent usages of pages
array and bitmap. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Conflicts:
arch/sparc/kernel/smp_64.c
arch/x86/kernel/cpu/perf_counter.c
arch/x86/kernel/setup_percpu.c
drivers/cpufreq/cpufreq_ondemand.c
mm/percpu.c
Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids. As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
get_vm_area() only accepts VM_* flags, not GFP_*.
And according to the doc of get_vm_area(), here should be
VM_ALLOC.
Signed-off-by: WANG Cong <amwang@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
percpu code has been assuming num_possible_cpus() == nr_cpu_ids which
is incorrect if cpu_possible_map contains holes. This causes percpu
code to access beyond allocated memories and vmalloc areas. On a
sparc64 machine with cpus 0 and 2 (u60), this triggers the following
warning or fails boot.
WARNING: at /devel/tj/os/work/mm/vmalloc.c:106 vmap_page_range_noflush+0x1f0/0x240()
Modules linked in:
Call Trace:
[00000000004b17d0] vmap_page_range_noflush+0x1f0/0x240
[00000000004b1840] map_vm_area+0x20/0x60
[00000000004b1950] __vmalloc_area_node+0xd0/0x160
[0000000000593434] deflate_init+0x14/0xe0
[0000000000583b94] __crypto_alloc_tfm+0xd4/0x1e0
[00000000005844f0] crypto_alloc_base+0x50/0xa0
[000000000058b898] alg_test_comp+0x18/0x80
[000000000058dad4] alg_test+0x54/0x180
[000000000058af00] cryptomgr_test+0x40/0x60
[0000000000473098] kthread+0x58/0x80
[000000000042b590] kernel_thread+0x30/0x60
[0000000000472fd0] kthreadd+0xf0/0x160
---[ end trace 429b268a213317ba ]---
This patch fixes generic percpu functions and sparc64
setup_per_cpu_areas() so that they handle sparse cpu_possible_map
properly.
Please note that on x86, cpu_possible_map() doesn't contain holes and
thus num_possible_cpus() == nr_cpu_ids and this patch doesn't cause
any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
clean up type-casting twice. "size_t" is typedef as "unsigned long" in
64-bit system, and "unsigned int" in 32-bit system, and the intermediate
cast to 'long' is pointless.
Signed-off-by: Figo.zhang <figo1802@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At first, init_task's mems_allowed is initialized as this.
init_task->mems_allowed == node_state[N_POSSIBLE]
And cpuset's top_cpuset mask is initialized as this
top_cpuset->mems_allowed = node_state[N_HIGH_MEMORY]
Before 2.6.29:
policy's mems_allowed is initialized as this.
1. update tasks->mems_allowed by its cpuset->mems_allowed.
2. policy->mems_allowed = nodes_and(tasks->mems_allowed, user's mask)
Updating task's mems_allowed in reference to top_cpuset's one.
cpuset's mems_allowed is aware of N_HIGH_MEMORY, always.
In 2.6.30: After commit 58568d2a82
("cpuset,mm: update tasks' mems_allowed in time"), policy's mems_allowed
is initialized as this.
1. policy->mems_allowd = nodes_and(task->mems_allowed, user's mask)
Here, if task is in top_cpuset, task->mems_allowed is not updated from
init's one. Assume user excutes command as #numactrl --interleave=all
,....
policy->mems_allowd = nodes_and(N_POSSIBLE, ALL_SET_MASK)
Then, policy's mems_allowd can includes a possible node, which has no pgdat.
MPOL's INTERLEAVE just scans nodemask of task->mems_allowd and access this
directly.
NODE_DATA(nid)->zonelist even if NODE_DATA(nid)==NULL
Then, what's we need is making policy->mems_allowed be aware of
N_HIGH_MEMORY. This patch does that. But to do so, extra nodemask will
be on statck. Because I know cpumask has a new interface of
CPUMASK_ALLOC(), I added it to node.
This patch stands on old behavior. But I feel this fix itself is just a
Band-Aid. But to do fundametal fix, we have to take care of memory
hotplug and it takes time. (task->mems_allowd should be N_HIGH_MEMORY, I
think.)
mpol_set_nodemask() should be aware of N_HIGH_MEMORY and policy's nodemask
should be includes only online nodes.
In old behavior, this is guaranteed by frequent reference to cpuset's
code. Now, most of them are removed and mempolicy has to check it by
itself.
To do check, a few nodemask_t will be used for calculating nodemask. But,
size of nodemask_t can be big and it's not good to allocate them on stack.
Now, cpumask_t has CPUMASK_ALLOC/FREE an easy code for get scratch area.
NODEMASK_ALLOC/FREE shoudl be there.
[akpm@linux-foundation.org: cleanups & tweaks]
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kmem_cache_init_late() has been declared in slab.h
CC: Nick Piggin <npiggin@suse.de>
CC: Matt Mackall <mpm@selenic.com>
CC: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
kmem_cache->align records the original align parameter value specified
by users. Function calculate_alignment might change it based on cache
line size. So change kmem_cache->align correspondingly.
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
The page allocator warns once when an order >= MAX_ORDER is specified.
This is to catch callers of the allocator that are always falling back to
their worst-case when it was not expected. However, there are cases where
the caller is behaving correctly but cannot suppress the warning. This
patch allows the warning to be suppressed by the callers by specifying
__GFP_NOWARN.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit ec64f51545 ("cgroup: fix
frequent -EBUSY at rmdir"), cgroup's rmdir (especially against memcg)
doesn't return -EBUSY by temporary ref counts. That commit expects all
refs after pre_destroy() is temporary but...it wasn't. Then, rmdir can
wait permanently. This patch tries to fix that and change followings.
- set CGRP_WAIT_ON_RMDIR flag before pre_destroy().
- clear CGRP_WAIT_ON_RMDIR flag when the subsys finds racy case.
if there are sleeping ones, wakes them up.
- rmdir() sleeps only when CGRP_WAIT_ON_RMDIR flag is set.
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Paul Menage <menage@google.com>
Acked-by: Balbir Sigh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported in Red Hat bz #509671, i_blocks for files on hugetlbfs get
accounting wrong when doing something like:
$ > foo
$ date > foo
date: write error: Invalid argument
$ /usr/bin/stat foo
File: `foo'
Size: 0 Blocks: 18446744073709547520 IO Block: 2097152 regular
...
This is because hugetlb_unreserve_pages() is unconditionally removing
blocks_per_huge_page(h) on each call rather than using the freed amount.
If there were 0 blocks, it goes negative, resulting in the above.
This is a regression from commit a551643895
("hugetlb: modular state for hugetlb page size")
which did:
- inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed;
+ inode->i_blocks -= blocks_per_huge_page(h);
so just put back the freed multiplier, and it's all happy again.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Andi Kleen <andi@firstfloor.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a task is oom killed and still cannot find memory when trying with
no watermarks, it's better to fail the allocation attempt than to loop
endlessly. Direct reclaim has already failed and the oom killer will
be a no-op since current has yet to die, so there is no other
alternative for allocations that are not __GFP_NOFAIL.
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a post-2.6.24 performace regression caused by
3dfa5721f1 ("page-allocator: preserve PFN
ordering when __GFP_COLD is set").
Narayanan reports "The regression is around 15%. There is no disk controller
as our setup is based on Samsung OneNAND used as a memory mapped device on a
OMAP2430 based board."
The page allocator tries to preserve contiguous PFN ordering when returning
pages such that repeated callers to the allocator have a strong chance of
getting physically contiguous pages, particularly when external fragmentation
is low. However, of the bulk of the allocations have __GFP_COLD set as they
are due to aio_read() for example, then the PFNs are in reverse PFN order.
This can cause performance degration when used with IO controllers that could
have merged the requests.
This patch attempts to preserve the contiguous ordering of PFNs for users of
__GFP_COLD.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reported-by: Narayananu Gopalakrishnan <narayanan.g@samsung.com>
Tested-by: Narayanan Gopalakrishnan <narayanan.g@samsung.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Objects passed to kmemleak_seq_next() have an incremented reference
count (hence not freed) but they may point via object_list.next to
other freed objects. To avoid this, the whole start/next/stop sequence
must be protected by rcu_read_lock().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create bdgrab(). This function copies an existing reference to a
block_device. It is safe to call from any context.
Hibernation code wishes to copy a reference to the active swap device.
Right now it calls bdget() under a spinlock, but this is wrong because
bdget() can sleep. It doesn't need a full bdget() because we already
hold a reference to active swap devices (and the spinlock protects
against swapoff).
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13827
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch moves the masking of debugging flags which increase a cache's
min order due to metadata when `slub_debug=O' is used from
kmem_cache_flags() to kmem_cache_open().
Instead of defining the maximum metadata size increase in a preprocessor
macro, this approach uses the cache's ->size and ->objsize members to
determine if the min order increased due to debugging options. If so,
the flags specified in the more appropriately named DEBUG_METADATA_FLAGS
are masked off.
This approach was suggested by Christoph Lameter
<cl@linux-foundation.org>.
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
mm: Pass virtual address to [__]p{te,ud,md}_free_tlb()
Upcoming paches to support the new 64-bit "BookE" powerpc architecture
will need to have the virtual address corresponding to PTE page when
freeing it, due to the way the HW table walker works.
Basically, the TLB can be loaded with "large" pages that cover the whole
virtual space (well, sort-of, half of it actually) represented by a PTE
page, and which contain an "indirect" bit indicating that this TLB entry
RPN points to an array of PTEs from which the TLB can then create direct
entries. Thus, in order to invalidate those when PTE pages are deleted,
we need the virtual address to pass to tlbilx or tlbivax instructions.
The old trick of sticking it somewhere in the PTE page struct page sucks
too much, the address is almost readily available in all call sites and
almost everybody implemets these as macros, so we may as well add the
argument everywhere. I added it to the pmd and pud variants for consistency.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Howells <dhowells@redhat.com> [MN10300 & FRV]
Acked-by: Nick Piggin <npiggin@suse.de>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: Remove alloc_bootmem annotations introduced in the past
kmemleak: Add callbacks to the bootmem allocator
kmemleak: Allow partial freeing of memory blocks
kmemleak: Trace the kmalloc_large* functions in slub
kmemleak: Scan objects allocated during a scanning episode
kmemleak: Do not acquire scan_mutex in kmemleak_open()
kmemleak: Remove the reported leaks number limitation
kmemleak: Add more cond_resched() calls in the scanning thread
kmemleak: Renice the scanning thread to +10
Commit 1faa16d228 accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
When debugging is enabled, slub requires that additional metadata be
stored in slabs for certain options: SLAB_RED_ZONE, SLAB_POISON, and
SLAB_STORE_USER.
Consequently, it may require that the minimum possible slab order needed
to allocate a single object be greater when using these options. The
most notable example is for objects that are PAGE_SIZE bytes in size.
Higher minimum slab orders may cause page allocation failures when oom or
under heavy fragmentation.
This patch adds a new slub_debug option, which disables debugging by
default for caches that would have resulted in higher minimum orders:
slub_debug=O
When this option is used on systems with 4K pages, kmalloc-4096, for
example, will not have debugging enabled by default even if
CONFIG_SLUB_DEBUG_ON is defined because it would have resulted in a
order-1 minimum slab order.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
kmemleak_alloc() calls were added in some places where alloc_bootmem was
called. Since now kmemleak tracks bootmem allocations, these explicit
calls should be run.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
This patch adds kmemleak_alloc/free callbacks to the bootmem allocator.
This would allow scanning of such blocks and help avoiding a whole class
of false positives and more kmemleak annotations.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Functions like free_bootmem() are allowed to free only part of a memory
block. This patch adds support for this via the kmemleak_free_part()
callback which removes the original object and creates one or two
additional objects as a result of the memory block split.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
The kmalloc_large() and kmalloc_large_node() functions were missed when
adding the kmemleak hooks to the slub allocator. However, they should be
traced to avoid false positives.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Many of the false positives in kmemleak happen on busy systems where
objects are allocated during a kmemleak scanning episode. These objects
aren't scanned by default until the next memory scan. When such object
is added, for example, at the head of a list, it is possible that all
the other objects in the list become unreferenced until the next scan.
This patch adds checking for newly allocated objects at the end of the
scan and repeats the scanning on these objects. If Linux allocates
new objects at a higher rate than their scanning, it stops after a
predefined number of passes.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Initially, the scan_mutex was acquired in kmemleak_open() and released
in kmemleak_release() (corresponding to /sys/kernel/debug/kmemleak
operations). This was causing some lockdep reports when the file was
closed from a different task than the one opening it. This patch moves
the scan_mutex acquiring in kmemleak_write() or kmemleak_seq_start()
with releasing in kmemleak_seq_stop().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Since the leaks are no longer printed to the syslog, there is no point
in keeping this limitation. All the suspected leaks are shown on
/sys/kernel/debug/kmemleak file.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Following recent fix to no longer reschedule in the scan_block()
function, the system may become unresponsive with !PREEMPT. This patch
re-adds the cond_resched() call to scan_block() but conditioned by the
allow_resched parameter.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
SLAB: Fix lockdep annotations
fix RCU-callback-after-kmem_cache_destroy problem in sl[aou]b
These warnings were observed on MIPS32 using 2.6.31-rc1 and gcc-4.2.0:
mm/page_alloc.c: In function 'alloc_pages_exact':
mm/page_alloc.c:1986: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast
drivers/usb/mon/mon_bin.c: In function 'mon_alloc_buff':
drivers/usb/mon/mon_bin.c:1264: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast
[akpm@linux-foundation.org: fix kernel/perf_counter.c too]
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In testing a backport of the write_begin/write_end AOPs, a 10% re-read
regression was noticed when running iozone. This regression was
introduced because the old AOPs would always do a mark_page_accessed(page)
after the commit_write, but when the new AOPs where introduced, the only
place this was kept was in pagecache_write_end().
This patch does the same thing in the generic case as what is done in
pagecache_write_end(), which is just to mark the page accessed before we
do write_end().
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Large page first chunk allocator is primarily used for NUMA machines;
however, its NUMA handling is extremely simplistic. Regardless of
their proximity, each cpu is put into separate large page just to
return most of the allocated space back wasting large amount of
vmalloc space and increasing cache footprint.
This patch teachs NUMA details to large page allocator. Given
processor proximity information, pcpu_lpage_build_unit_map() will find
fitting cpu -> unit mapping in which cpus in LOCAL_DISTANCE share the
same large page and not too much virtual address space is wasted.
This greatly reduces the unit and thus chunk size and wastes much less
address space for the first chunk. For example, on 4/4 NUMA machine,
the original code occupied 16MB of virtual space for the first chunk
while the new code only uses 4MB - one 2MB page for each node.
[ Impact: much better space efficiency on NUMA machines ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Miller <davem@davemloft.net>
Currently cpu and unit are always identity mapped. To allow more
efficient large page support on NUMA and lazy allocation for possible
but offline cpus, cpu -> unit mapping needs to be non-linear and/or
sparse. This can be easily implemented by adding a cpu -> unit
mapping array and using it whenever looking up the matching unit for a
cpu.
The only unusal conversion is in pcpu_chunk_addr_search(). The passed
in address is unit0 based and unit0 might not be in use so it needs to
be converted to address of an in-use unit. This is easily done by
adding the unit offset for the current processor.
[ Impact: allows non-linear/sparse cpu -> unit mapping, no visible change yet ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
percpu core doesn't need to tack all the allocated pages. It needs to
know whether certain pages are populated and a way to reverse map
address to page when freeing. This patch drops pcpu_chunk->page[] and
use populated bitmap and vmalloc_to_page() lookup instead. Using
vmalloc_to_page() exclusively is also possible but complicates first
chunk handling, inflates cache footprint and prevents non-standard
memory allocation for percpu memory.
pcpu_chunk->page[] was used to track each page's allocation and
allowed asymmetric population which happens during failure path;
however, with single bitmap for all units, this is no longer possible.
Bite the bullet and rewrite (de)populate functions so that things are
done in clearly separated steps such that asymmetric population
doesn't happen. This makes the (de)population process much more
modular and will also ease implementing non-standard memory usage in
the future (e.g. large pages).
This makes @get_page_fn parameter to pcpu_setup_first_chunk()
unnecessary. The parameter is dropped and all first chunk helpers are
updated accordingly. Please note that despite the volume most changes
to first chunk helpers are symbol renames for variables which don't
need to be referenced outside of the helper anymore.
This change reduces memory usage and cache footprint of pcpu_chunk.
Now only #unit_pages bits are necessary per chunk.
[ Impact: reduced memory usage and cache footprint for bookkeeping ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
(de)populate functions are about to be reimplemented to drop
pcpu_chunk->page array. Move a few functions so that the rewrite
patch doesn't have code movement making it more difficult to read.
[ Impact: code movement ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Now that all first chunk allocator helpers allocate and map the first
chunk themselves, there's no need to have optional default alloc/map
in pcpu_setup_first_chunk(). Drop @populate_pte_fn and only leave
@dyn_size optional and make all other params mandatory.
This makes it much easier to follow what pcpu_setup_first_chunk() is
doing and what actual differences tweaking each parameter results in.
[ Impact: drop unused code path ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Generalize and move x86 setup_pcpu_lpage() into
pcpu_lpage_first_chunk(). setup_pcpu_lpage() now is a simple wrapper
around the generalized version. Other than taking size parameters and
using arch supplied callbacks to allocate/free/map memory,
pcpu_lpage_first_chunk() is identical to the original implementation.
This simplifies arch code and will help converting more archs to
dynamic percpu allocator.
While at it, factor out pcpu_calc_fc_sizes() which is common to
pcpu_embed_first_chunk() and pcpu_lpage_first_chunk().
[ Impact: code reorganization and generalization ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
At first, percpu first chunk was always setup page-by-page by the
generic code. To add other allocators, different parts of the generic
initialization was made optional. Now we have three allocators -
embed, remap and 4k. embed and remap fully handle allocation and
mapping of the first chunk while 4k still depends on generic code for
those. This makes the generic alloc/map paths specifci to 4k and
makes the code unnecessary complicated with optional generic
behaviors.
This patch makes the 4k allocator to allocate and map memory directly
instead of depending on the generic code. The only outside visible
change is that now dynamic area in the first chunk is allocated
up-front instead of on-demand. This doesn't make any meaningful
difference as the area is minimal (usually less than a page, just
enough to fill the alignment) on 4k allocator. Plus, dynamic area in
the first chunk usually gets fully used anyway.
This will allow simplification of pcpu_setpu_first_chunk() and removal
of chunk->page array.
[ Impact: no outside visible change other than up-front allocation of dyn area ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Generalize and move x86 setup_pcpu_4k() into pcpu_4k_first_chunk().
setup_pcpu_4k() now is a simple wrapper around the generalized
version. Other than taking size parameters and using arch supplied
callbacks to allocate/free memory, pcpu_4k_first_chunk() is identical
to the original implementation.
This simplifies arch code and will help converting more archs to
dynamic percpu allocator.
While at it, s/pcpu_populate_pte_fn_t/pcpu_fc_populate_pte_fn_t/ for
consistency.
[ Impact: code reorganization and generalization ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
The only extra feature @unit_size provides is making dead space at the
end of the first chunk which doesn't have any valid usecase. Drop the
parameter. This will increase consistency with generalized 4k
allocator.
James Bottomley spotted missing conversion for the default
setup_per_cpu_areas() which caused build breakage on all arcsh which
use it.
[ Impact: drop unused code path ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Ingo Molnar <mingo@elte.hu>
The @addr passed into pcpu_chunk_addr_search() is unit0 based address
and thus should be matched inside unit0 area. Currently, when it uses
chunk size when determining whether the address falls in the first
chunk. Addresses in unitN where N>0 shouldn't be passed in anyway, so
this doesn't cause any malfunction but fix it for consistency.
[ Impact: mostly cleanup ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Pull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix
changes. As alpha in percpu tree uses 'weak' attribute instead of
inline assembly, there's no need for __used attribute.
Conflicts:
arch/alpha/include/asm/percpu.h
arch/mn10300/kernel/vmlinux.lds.S
include/linux/percpu-defs.h
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
sh: LCDC dcache flush for deferred io
sh: Fix compiler error and include the definition of IS_ERR_VALUE
sh: re-add LCDC fbdev support to the Migo-R defconfig
sh: fix se7724 ceu names
sh: ms7724se: Enable sh_eth in defconfig.
arch/sh/boards/mach-se/7206/io.c: Remove unnecessary semicolons
sh: ms7724se: Add sh_eth support
nommu: provide follow_pfn().
sh: Kill off unused DEBUG_BOOTMEM symbol.
perf_counter tools: add cpu_relax()/rmb() definitions for sh.
sh64: Hook up page fault events for software perf counters.
sh: Hook up page fault events for software perf counters.
sh: make set_perf_counter_pending() static inline.
clocksource: sh_tmu: Make undefined TCOR behaviour less undefined.
One of the kmemleak changes caused the following
scheduling-while-holding-the-tasklist-lock regression on x86:
BUG: sleeping function called from invalid context at mm/kmemleak.c:795
in_atomic(): 1, irqs_disabled(): 0, pid: 1737, name: kmemleak
2 locks held by kmemleak/1737:
#0: (scan_mutex){......}, at: [<c10c4376>] kmemleak_scan_thread+0x45/0x86
#1: (tasklist_lock){......}, at: [<c10c3bb4>] kmemleak_scan+0x1a9/0x39c
Pid: 1737, comm: kmemleak Not tainted 2.6.31-rc1-tip #59266
Call Trace:
[<c105ac0f>] ? __debug_show_held_locks+0x1e/0x20
[<c102e490>] __might_sleep+0x10a/0x111
[<c10c38d5>] scan_yield+0x17/0x3b
[<c10c3970>] scan_block+0x39/0xd4
[<c10c3bc6>] kmemleak_scan+0x1bb/0x39c
[<c10c4331>] ? kmemleak_scan_thread+0x0/0x86
[<c10c437b>] kmemleak_scan_thread+0x4a/0x86
[<c104d73e>] kthread+0x6e/0x73
[<c104d6d0>] ? kthread+0x0/0x73
[<c100959f>] kernel_thread_helper+0x7/0x10
kmemleak: 834 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
The bit causing it is highly dubious:
static void scan_yield(void)
{
might_sleep();
if (time_is_before_eq_jiffies(next_scan_yield)) {
schedule();
next_scan_yield = jiffies + jiffies_scan_yield;
}
}
It called deep inside the codepath and in a conditional way,
and that is what crapped up when one of the new scan_block()
uses grew a tasklist_lock dependency.
This minimal patch removes that yielding stuff and adds the
proper cond_resched().
The background scanning thread could probably also be reniced
to +10.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: Inform kmemleak about pid_hash
kmemleak: Do not warn if an unknown object is freed
kmemleak: Do not report new leaked objects if the scanning was stopped
kmemleak: Slightly change the policy on newly allocated objects
kmemleak: Do not trigger a scan when reading the debug/kmemleak file
kmemleak: Simplify the reports logged by the scanning thread
kmemleak: Enable task stacks scanning by default
kmemleak: Allow the early log buffer to be configurable.
Nathan reported that
| commit 73d60b7f74
| Author: Yinghai Lu <yinghai@kernel.org>
| Date: Tue Jun 16 15:33:00 2009 -0700
|
| page-allocator: clear N_HIGH_MEMORY map before we set it again
|
| SRAT tables may contains nodes of very small size. The arch code may
| decide to not activate such a node. However, currently the early boot
| code sets N_HIGH_MEMORY for such nodes. These nodes therefore seem to be
| active although these nodes have no present pages.
|
| For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too
unintentionally and incorrectly clears the cpuset.mems cgroup attribute on
an i386 kvm guest, meaning that cpuset.mems can not be used.
Fix this by only clearing node_states[N_NORMAL_MEMORY] for 64bit only.
and need to do save/restore for that in find_zone_movable_pfn
Reported-by: Nathan Lynch <ntl@pobox.com>
Tested-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
balance_dirty_pages can overreact and move all of the dirty pages to
writeback unnecessarily.
balance_dirty_pages makes its decision to throttle based on the number of
dirty plus writeback pages that are over the calculated limit,so it will
continue to move pages even when there are plenty of pages in writeback
and less than the threshold still dirty.
This allows it to overshoot its limits and move all the dirty pages to
writeback while waiting for the drives to catch up and empty the writeback
list.
A simple fio test easily demonstrates this problem.
fio --name=f1 --directory=/disk1 --size=2G -rw=write --name=f2 --directory=/disk2 --size=1G --rw=write --startdelay=10
This is the simplest fix I could find, but I'm not entirely sure that it
alone will be enough for all cases. But it certainly is an improvement on
my desktop machine writing to 2 disks.
Do we need something more for machines with large arrays where
bdi_threshold * number_of_drives is greater than the dirty_ratio ?
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
show_pools() walks the page_list of a pool w/o protection against the list
modifications in alloc/free. Take pool->lock to avoid stomping into
nirvana.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmap'ed memory blocks are not tracked by kmemleak (yet) but they may be
released with vfree() which is tracked. The corresponding kmemleak
warning is only enabled in debug mode. Future patch will add support for
ioremap and vmap.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
If the scanning was stopped with a signal, it is possible that some
objects are left with a white colour (potential leaks) and reported. Add
a check to avoid reporting such objects.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, delay: tsc based udelay should have rdtsc_barrier
x86, setup: correct include file in <asm/boot.h>
x86, setup: Fix typo "CONFIG_x86_64" in <asm/boot.h>
x86, mce: percpu mcheck_timer should be pinned
x86: Add sysctl to allow panic on IOCK NMI error
x86: Fix uv bau sending buffer initialization
x86, mce: Fix mce resume on 32bit
x86: Move init_gbpages() to setup_arch()
x86: ensure percpu lpage doesn't consume too much vmalloc space
x86: implement percpu_alloc kernel parameter
x86: fix pageattr handling for lpage percpu allocator and re-enable it
x86: reorganize cpa_process_alias()
x86: prepare setup_pcpu_lpage() for pageattr fix
x86: rename remap percpu first chunk allocator to lpage
x86: fix duplicate free in setup_pcpu_remap() failure path
percpu: fix too lazy vunmap cache flushing
x86: Set cpu_llc_id on AMD CPUs
Newly allocated objects are more likely to be reported as false
positives. Kmemleak ignores the reporting of objects younger than 5
seconds. However, this age was calculated after the memory scanning
completed which usually takes longer than 5 seconds. This patch
make the minimum object age calculation in relation to the start of the
memory scanning.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Since there is a kernel thread for automatically scanning the memory, it
makes sense for the debug/kmemleak file to only show its findings. This
patch also adds support for "echo scan > debug/kmemleak" to trigger an
intermediate memory scan and eliminates the kmemleak_mutex (scan_mutex
covers all the cases now).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Because of false positives, the memory scanning thread may print too
much information. This patch changes the scanning thread to only print
the number of newly suspected leaks. Further information can be read
from the /sys/kernel/debug/kmemleak file.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Jesper noted that kmem_cache_destroy() invokes synchronize_rcu() rather than
rcu_barrier() in the SLAB_DESTROY_BY_RCU case, which could result in RCU
callbacks accessing a kmem_cache after it had been destroyed.
Cc: <stable@kernel.org>
Acked-by: Matt Mackall <mpm@selenic.com>
Reported-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
With the introduction of follow_pfn() as an exported symbol, modules have
begun making use of it. Unfortunately this was not reflected on nommu at
the time, so the in-tree users have subsequently all blown up with link
errors there.
This provides a simple follow_pfn() that just returns addr >> PAGE_SHIFT,
which will do the right thing on nommu. There is no need to do range
checking within the vma, as the find_vma() case will already take care of
this.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Currently the 4th parameter of get_user_pages() is called len, but its
in pages, not bytes. Rename the thing to nr_pages to avoid future
confusion.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(feature suggested by Sergey Senozhatsky)
Kmemleak needs to track all the memory allocations but some of these
happen before kmemleak is initialised. These are stored in an internal
buffer which may be exceeded in some kernel configurations. This patch
adds a configuration option with a default value of 400 and also removes
the stack dump when the early log buffer is exceeded.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
another race fix in jfs_check_acl()
Get "no acls for this inode" right, fix shmem breakage
inline functions left without protection of ifdef (acl)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
audit: inode watches depend on CONFIG_AUDIT not CONFIG_AUDIT_SYSCALL
SLUB uses higher order allocations by default but falls back to small
orders under memory pressure. Make sure the GFP mask used in the initial
allocation doesn't include __GFP_NOFAIL.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Traditionally, we never failed small orders (even regardless of any
__GFP_NOFAIL flags), and slab will allocate order-1 allocations even for
small allocations that could fit in a single page (in order to avoid
excessive fragmentation).
Maybe we should remove this warning entirely, but before making that
judgement, at least limit it to bigger allocations.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Percpu variable definition is about to be updated such that all percpu
symbols including the static ones must be unique. Update percpu
variable definitions accordingly.
* as,cfq: rename ioc_count uniquely
* cpufreq: rename cpu_dbs_info uniquely
* xen: move nesting_count out of xen_evtchn_do_upcall() and rename it
* mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and
rename it
* ipv4,6: rename cookie_scratch uniquely
* x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to
pmc_irq_entry and nmi_entry to pmc_nmi_entry
* perf_counter: rename disable_count to perf_disable_count
* ftrace: rename test_event_disable to ftrace_test_event_disable
* kmemleak: rename test_pointer to kmemleak_test_pointer
* mce: rename next_interval to mce_next_interval
[ Impact: percpu usage cleanups, no duplicate static percpu var names ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm <linux-mm@kvack.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Currently, the following three different ways to define percpu arrays
are in use.
1. DEFINE_PER_CPU(elem_type[array_len], array_name);
2. DEFINE_PER_CPU(elem_type, array_name[array_len]);
3. DEFINE_PER_CPU(elem_type, array_name)[array_len];
Unify to #1 which correctly separates the roles of the two parameters
and thus allows more flexibility in the way percpu variables are
defined.
[ Impact: cleanup ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm@kvack.org
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use
dynamic percpu allocator. The first chunk is allocated using
embedding helper and 8k is reserved for modules. This ensures that
the new allocator behaves almost identically to the original allocator
as long as static percpu variables are concerned, so it shouldn't
introduce much breakage.
s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing
range limit the addressing model imposes. Unfortunately, this breaks
if the address is specified using a variable, so for now, the two
archs aren't converted.
The following architectures are affected by this change.
* sh
* arm
* cris
* mips
* sparc(32)
* blackfin
* avr32
* parisc (broken, under investigation)
* m32r
* powerpc(32)
As this change makes the dynamic allocator the default one,
CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert -
CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted
archs. These archs implement their own setup_per_cpu_areas() and the
conversion is not trivial.
* powerpc(64)
* sparc(64)
* ia64
* alpha
* s390
Boot and batch alloc/free tests on x86_32 with debug code (x86_32
doesn't use default first chunk initialization). Compile tested on
sparc(32), powerpc(32), arm and alpha.
Kyle McMartin reported that this change breaks parisc. The problem is
still under investigation and he is okay with pushing this patch
forward and fixing parisc later.
[ Impact: use dynamic allocator for most archs w/o custom percpu setup ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
After downing/upping a cpu, an attempt to set
/proc/sys/vm/percpu_pagelist_fraction results in an oops in
percpu_pagelist_fraction_sysctl_handler().
If a processor is downed then we need to set the pageset pointer back to
the boot pageset.
Updates of the high water marks should not access pagesets of unpopulated
zones (those pointer go to the boot pagesets which would be no longer
functional if their size would be increased beyond zero).
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a kthread happens to use get_user_pages() on an mm (as KSM does),
there's a chance that it will end up trying to read in a swap page, then
oops in grab_swap_token() because the kthread has no mm: GUP passes down
the right mm, so grab_swap_token() ought to be using it.
We have not identified a stronger case than KSM's daemon (not yet in
mainline), but the issue must have come up before, since RHEL has included
a fix for this for years (though a different fix, they just back out of
grab_swap_token if current->mm is unset: which is what we first proposed,
but using the right mm here seems more correct).
Reported-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Indeed FOLL_WRITE matches FAULT_FLAG_WRITE, matches GUP_FLAGS_WRITE,
and it's tempting to devise a set of Grand Unified Paging flags;
but not today. So until then, let's rely upon the compiler to spot
the coincidence, "rather than have that subtle dependency and a
comment for it" - as you remarked in another context yesterday.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
handle_mm_fault() is now passing fault flags rather than write_access
down to hugetlb_fault(), so better recognize that in hugetlb_fault(),
and in hugetlb_no_page().
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The isolated page is "cursor_page" not "page".
This could cause LRU list corruption under memory pressure, caught by
CONFIG_DEBUG_LIST.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
According to Andi, it isn't clear whether lpage allocator is worth the
trouble as there are many processors where PMD TLB is far scarcer than
PTE TLB. The advantage or disadvantage probably depends on the actual
size of percpu area and specific processor. As performance
degradation due to TLB pressure tends to be highly workload specific
and subtle, it is difficult to decide which way to go without more
data.
This patch implements percpu_alloc kernel parameter to allow selecting
which first chunk allocator to use to ease debugging and testing.
While at it, make sure all the failure paths report why something
failed to help determining why certain allocator isn't working. Also,
kill the "Great future plan" comment which had already been realized
quite some time ago.
[ Impact: allow explicit percpu first chunk allocator selection ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
In pcpu_unmap(), flushing virtual cache on vunmap can't be delayed as
the page is going to be returned to the page allocator. Only TLB
flushing can be put off such that vmalloc code can handle it lazily.
Fix it.
[ Impact: fix subtle virtual cache flush bug ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
This allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault(). All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The fault handling routines really want more fine-grained flags than a
single "was it a write fault" boolean - the callers will want to set
flags like "you can return a retry error" etc.
And that's actually how the VM works internally, but right now the
top-level fault handling functions in mm/memory.c all pass just the
'write_access' boolean around.
This switches them over to pass around the FAULT_FLAG_xyzzy 'flags'
variable instead. The 'write_access' calling convention still exists
for the exported 'handle_mm_fault()' function, but that is next.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
da456f1 "page allocator: do not disable interrupts in free_page_mlock()" moved
the PG_mlocked clearing after the flag sanity checking which makes mlocked
pages always trigger 'bad page'. Fix this by clearing the bit up front.
Reported--and-debugged-by: Peter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page allocator also needs the masking of gfp flags during boot,
so this moves it out of slab/slub and uses it with the page allocator
as well.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Try to fix memcg's lru rotation sanity: make memcg use the same logic as
the global LRU does.
Now, at __isolate_lru_page() retruns -EBUSY, the page is rotated to the
tail of LRU in global LRU's isolate LRU pages. But in memcg, it's not
handled. This makes memcg do the same behavior as global LRU and rotate
LRU in the page is busy.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A user can set memcg.limit_in_bytes == memcg.memsw.limit_in_bytes when the
user just want to limit the total size of applications, in other words,
not very interested in memory usage itself. In this case, swap-out will
be done only by global-LRU.
But, under current implementation, memory.limit_in_bytes is checked at
first and try_to_free_page() may do swap-out. But, that swap-out is
useless for memsw.limit_in_bytes and the thread may hit limit again.
This patch tries to fix the current behavior at memory.limit ==
memsw.limit case. And documentation is updated to explain the behavior of
this special case.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes mis-accounting of swap usage in memcg.
In the current implementation, memcg's swap account is uncharged only when
swap is completely freed. But there are several cases where swap cannot
be freed cleanly. For handling that, this patch changes that memcg
uncharges swap account when swap has no references other than cache.
By this, memcg's swap entry accounting can be fully synchronous with the
application's behavior.
This patch also changes memcg's hooks for swap-out.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't need to check do_swap_account in the case that the function which
checks do_swap_account will never get called if do_swap_account == 0.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add file RSS tracking per memory cgroup
We currently don't track file RSS, the RSS we report is actually anon RSS.
All the file mapped pages, come in through the page cache and get
accounted there. This patch adds support for accounting file RSS pages.
It should
1. Help improve the metrics reported by the memory resource controller
2. Will form the basis for a future shared memory accounting heuristic
that has been proposed by Kamezawa.
Unfortunately, we cannot rename the existing "rss" keyword used in
memory.stat to "anon_rss". We however, add "mapped_file" data and hope to
educate the end user through documentation.
[hugh.dickins@tiscali.co.uk: fix mem_cgroup_update_mapped_file_stat oops]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.cn>
Cc: Paul Menage <menage@google.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix some cgroup messages to read better.
Update MAINTAINERS to include mm/*cgroup* files.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: Fix some typos in comments
kmemleak: Rename kmemleak_panic to kmemleak_stop
kmemleak: Only use GFP_KERNEL|GFP_ATOMIC for the internal allocations
This is to avoid the confusion created by the "panic" word.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Kmemleak allocates memory for pointer tracking and it tries to avoid
using GFP_ATOMIC if the caller doesn't require it. However other gfp
flags may be passed by the caller which aren't required by kmemleak.
This patch filters the gfp flags so that only GFP_KERNEL | GFP_ATOMIC
are used.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
* akpm: (182 commits)
fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
fbdev: *bfin*: fix __dev{init,exit} markings
fbdev: *bfin*: drop unnecessary calls to memset
fbdev: bfin-t350mcqb-fb: drop unused local variables
fbdev: blackfin has __raw I/O accessors, so use them in fb.h
fbdev: s1d13xxxfb: add accelerated bitblt functions
tcx: use standard fields for framebuffer physical address and length
fbdev: add support for handoff from firmware to hw framebuffers
intelfb: fix a bug when changing video timing
fbdev: use framebuffer_release() for freeing fb_info structures
radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
s3c-fb: CPUFREQ frequency scaling support
s3c-fb: fix resource releasing on error during probing
carminefb: fix possible access beyond end of carmine_modedb[]
acornfb: remove fb_mmap function
mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
mb862xxfb: restrict compliation of platform driver to PPC
Samsung SoC Framebuffer driver: add Alpha Channel support
atmel-lcdc: fix pixclock upper bound detection
offb: use framebuffer_alloc() to allocate fb_info struct
...
Manually fix up conflicts due to kmemcheck in mm/slab.c
At lumpy reclaim, a page failed to be taken by __isolate_lru_page() can be
pushed back to "src" list by list_move(). But the page may not be from
"src" list. This pushes the page back to wrong LRU. And list_move()
itself is unnecessary because the page is not on top of LRU. Then, leave
it as it is if __isolate_lru_page() fails.
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On NUMA machines, the administrator can configure zone_reclaim_mode that
is a more targetted form of direct reclaim. On machines with large NUMA
distances for example, a zone_reclaim_mode defaults to 1 meaning that
clean unmapped pages will be reclaimed if the zone watermarks are not
being met.
There is a heuristic that determines if the scan is worthwhile but it is
possible that the heuristic will fail and the CPU gets tied up scanning
uselessly. Detecting the situation requires some guesswork and
experimentation so this patch adds a counter "zreclaim_failed" to
/proc/vmstat. If during high CPU utilisation this counter is increasing
rapidly, then the resolution to the problem may be to set
/proc/sys/vm/zone_reclaim_mode to 0.
[akpm@linux-foundation.org: name things consistently]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On NUMA machines, the administrator can configure zone_reclaim_mode that
is a more targetted form of direct reclaim. On machines with large NUMA
distances for example, a zone_reclaim_mode defaults to 1 meaning that
clean unmapped pages will be reclaimed if the zone watermarks are not
being met. The problem is that zone_reclaim() failing at all means the
zone gets marked full.
This can cause situations where a zone is usable, but is being skipped
because it has been considered full. Take a situation where a large tmpfs
mount is occuping a large percentage of memory overall. The pages do not
get cleaned or reclaimed by zone_reclaim(), but the zone gets marked full
and the zonelist cache considers them not worth trying in the future.
This patch makes zone_reclaim() return more fine-grained information about
what occured when zone_reclaim() failued. The zone only gets marked full
if it really is unreclaimable. If it's a case that the scan did not occur
or if enough pages were not reclaimed with the limited reclaim_mode, then
the zone is simply skipped.
There is a side-effect to this patch. Currently, if zone_reclaim()
successfully reclaimed SWAP_CLUSTER_MAX, an allocation attempt would go
ahead. With this patch applied, zone watermarks are rechecked after
zone_reclaim() does some work.
This bug was introduced by commit 9276b1bc96
("memory page_alloc zonelist caching speedup") way back in 2.6.19 when the
zonelist_cache was introduced. It was not intended that zone_reclaim()
aggressively consider the zone to be full when it failed as full direct
reclaim can still be an option. Due to the age of the bug, it should be
considered a -stable candidate.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
