Provide a threshold to relax the mlock accounting, increasing usability.
Each counter gets perf_counter_mlock_kb for free.
[ Impact: allow more mmap buffering ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090505155437.112113632@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Provide a way to reset an existing counter - this eases PAPI
libraries around perfcounters.
Similar to read() it doesn't collapse pending child counters.
[ Impact: new perfcounter fd ioctl method to reset counters ]
Suggested-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090505155437.022272933@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Keep data_head up-to-date irrespective of notifications. This fixes
the case where you disable a counter and don't get a notification for
the last few pending events, and it also allows polling usage.
[ Impact: increase precision of perfcounter mmap-ed fields ]
Suggested-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090505155436.925084300@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
percpu scheduling for perfcounters wants to take the context lock,
but that lock first needs to be initialized. Currently it is an
early_initcall() - but that is too late, the task tick runs much
sooner than that.
Call it explicitly from the scheduler init sequence instead.
[ Impact: fix access-before-init crash ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When two (or more) contexts output to the same buffer, it is possible
to observe half written output.
Suppose we have CPU0 doing perf_counter_mmap(), CPU1 doing
perf_counter_overflow(). If CPU1 does a wakeup and exposes head to
user-space, then CPU2 can observe the data CPU0 is still writing.
[ Impact: fix occasionally corrupted profiling records ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.007821627@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is necessary to avoid the conflict of syscall numbers.
Conflicts:
arch/x86/ia32/ia32entry.S
arch/x86/include/asm/unistd_32.h
arch/x86/include/asm/unistd_64.h
Fixes up the borked syscall numbers of perfcounters versus
preadv/pwritev as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
sys_kill has the per thread counterpart sys_tgkill. sigqueueinfo is
missing a thread directed counterpart. Such an interface is important
for migrating applications from other OSes which have the per thread
delivery implemented.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Ulrich Drepper <drepper@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (24 commits)
e100: do not go D3 in shutdown unless system is powering off
netfilter: revised locking for x_tables
Bluetooth: Fix connection establishment with low security requirement
Bluetooth: Add different pairing timeout for Legacy Pairing
Bluetooth: Ensure that HCI sysfs add/del is preempt safe
net: Avoid extra wakeups of threads blocked in wait_for_packet()
net: Fix typo in net_device_ops description.
ipv4: Limit size of route cache hash table
Add reference to CAPI 2.0 standard
Documentation/isdn/INTERFACE.CAPI
update Documentation/isdn/00-INDEX
ixgbe: Fix WoL functionality for 82599 KX4 devices
veth: prevent oops caused by netdev destructor
xfrm: wrong hash value for temporary SA
forcedeth: tx timeout fix
net: Fix LL_MAX_HEADER for CONFIG_TR_MODULE
mlx4_en: Handle page allocation failure during receive
mlx4_en: Fix cleanup flow on cq activation
vlan: update vlan carrier state for admin up/down
netfilter: xt_recent: fix stack overread in compat code
...
The type of counter index is sometimes implemented as unsigned
int. This patch changes this to have a consistent usage of int.
[ Impact: cleanup ]
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-21-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch renames struct hw_perf_counter_ops into struct pmu. It
introduces a structure to describe a cpu specific pmu (performance
monitoring unit). It may contain ops and data. The new name of the
structure fits better, is shorter, and thus better to handle. Where it
was appropriate, names of function and variable have been changed too.
[ Impact: cleanup ]
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-7-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is only needed for CONFIG_PERF_COUNTERS enabled.
[ Impact: cleanup ]
Signed-off-by: Robert Richter <robert.richter@amd.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1241002046-8832-3-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The x_tables are organized with a table structure and a per-cpu copies
of the counters and rules. On older kernels there was a reader/writer
lock per table which was a performance bottleneck. In 2.6.30-rc, this
was converted to use RCU and the counters/rules which solved the performance
problems for do_table but made replacing rules much slower because of
the necessary RCU grace period.
This version uses a per-cpu set of spinlocks and counters to allow to
table processing to proceed without the cache thrashing of a global
reader lock and keeps the same performance for table updates.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
drm/i915: fix up error path leak in i915_cmdbuffer
drm/i915: fix unpaired i915 device mutex on entervt failure.
drm/i915: add support for G41 chipset
drm/i915: Enable ASLE if present
drm/i915: Unregister ACPI video driver when exiting
drm/i915: Register ACPI video even when not modesetting
drm/i915: fix transition to I915_TILING_NONE
drm/i915: Don't let an oops get triggered from irq_emit without dma init.
drm/i915: allow tiled front buffers on 965+
Add regulator header file missing kernel-doc:
Warning(include/linux/regulator/driver.h:117): No description found for parameter 'set_mode'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
cc: Liam Girdwood <lrg@slimlogic.co.uk>
cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
The Bluetooth stack uses a reference counting for all established ACL
links and if no user (L2CAP connection) is present, the link will be
terminated to save power. The problem part is the dedicated pairing
when using Legacy Pairing (Bluetooth 2.0 and before). At that point
no user is present and pairing attempts will be disconnected within
10 seconds or less. In previous kernel version this was not a problem
since the disconnect timeout wasn't triggered on incoming connections
for the first time. However this caused issues with broken host stacks
that kept the connections around after dedicated pairing. When the
support for Simple Pairing got added, the link establishment procedure
needed to be changed and now causes issues when using Legacy Pairing
When using Simple Pairing it is possible to do a proper reference
counting of ACL link users. With Legacy Pairing this is not possible
since the specification is unclear in some areas and too many broken
Bluetooth devices have already been deployed. So instead of trying to
deal with all the broken devices, a special pairing timeout will be
introduced that increases the timeout to 60 seconds when pairing is
triggered.
If a broken devices now puts the stack into an unforeseen state, the
worst that happens is the disconnect timeout triggers after 120 seconds
instead of 4 seconds. This allows successful pairings with legacy and
broken devices now.
Based on a report by Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In 2.6.25 we added UDP mem accounting.
This unfortunatly added a penalty when a frame is transmitted, since
we have at TX completion time to call sock_wfree() to perform necessary
memory accounting. This calls sock_def_write_space() and utimately
scheduler if any thread is waiting on the socket.
Thread(s) waiting for an incoming frame was scheduled, then had to sleep
again as event was meaningless.
(All threads waiting on a socket are using same sk_sleep anchor)
This adds lot of extra wakeups and increases latencies, as noted
by Christoph Lameter, and slows down softirq handler.
Reference : http://marc.info/?l=linux-netdev&m=124060437012283&w=2
Fortunatly, Davide Libenzi recently added concept of keyed wakeups
into kernel, and particularly for sockets (see commit
37e5540b3c
epoll keyed wakeups: make sockets use keyed wakeups)
Davide goal was to optimize epoll, but this new wakeup infrastructure
can help non epoll users as well, if they care to setup an appropriate
handler.
This patch introduces new DEFINE_WAIT_FUNC() helper and uses it
in wait_for_packet(), so that only relevant event can wakeup a thread
blocked in this function.
Trace of function calls from bnx2 TX completion bnx2_poll_work() is :
__kfree_skb()
skb_release_head_state()
sock_wfree()
sock_def_write_space()
__wake_up_sync_key()
__wake_up_common()
receiver_wake_function() : Stops here since thread is waiting for an INPUT
Reported-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The old refok sections
.text.init.refok
.data.init.refok
.exit.text.refok
have been deprecated since commit
312b1485fb. After the other patches in
this patch series nothing is put in these sections, so clean things up
by eliminating all the remaining references to them.
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: only save/restore existent registers in the PCIe capability
x86/PCI: don't bother with root quirks if _CRS is used
docbooks: add/fix PCI kernel-doc
PCI: cleanup debug output resources
x86/PCI: set_pci_bus_resources_arch_default cleanups
x86/PCI: Move set_pci_bus_resources_arch_default into arch/x86
x86/PCI: don't call e820_all_mapped with -1 in the mmconfig case
PCI quirk: disable MSI on VIA VT3364 chipsets
This patch is preparation for replacing all uses of ".head.text" or
".text.head" in the kernel with macros, so that the section name can
later be changed without having to touch a lot of the kernel.
Since some linker scripts do more complex things than referencing
HEAD_TEXT, we add a HEAD_TEXT_SECTION macro that just contains the
actual name.
I've defined HEAD_TEXT_SECTION in a new header,
include/linux/section-names.h, so that this section name only needs to
appear in one place. I anticipate creating similar macro structures
for a number of other section names.
The long-term goal here is to be able to change the kernel's magic
section names to those that are compatible with -ffunction-sections
-fdata-sections. This requires renaming all magic sections with names
of the form ".text.foo".
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (34 commits)
ACPI, i915: Register ACPI video even when not modesetting
Revert "ACPICA: delete check for AML access to port 0x81-83"
I/O port protection: update for windows compatibility.
sony-laptop: always try to unblock rfkill on load
sony-laptop: fix bogus error message display on resume
ACPI: EC: Fix ACPI EC resume non-query interrupt message
sony-laptop: SNC input event 38 fix
sony-laptop: SNC 127 Initialization Fix
sony-laptop: Duplicate SNC 127 Event Fix
ACPI: prevent processor.max_cstate=0 boot crash
ACPI/hpet: prevent boot hang when hpet=force used on ICH-4M
ACPI: delete obsolete "bus master activity" proc field
ACPI: idle: mark_tsc_unstable() at init-time, not run-time
ACPI: add /sys/firmware/acpi/interrupts/sci_not counter
ACPI video: fix an error when the brightness levels on AC and on Battery are same
acpi-cpufreq: Do not let get_measured perf depend on internal variable
acpi-cpufreq: style-only: add parens to math expression
acpi-cpufreq: Cleanup: Use printk_once
x86, acpi_cpufreq: Fix the NULL pointer dereference in get_measured_perf
thinkpad-acpi: bump up version to 0.23
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Fix potential inode allocation soft lockup in Orlov allocator
ext4: Make the extent validity check more paranoid
jbd: use SWRITE_SYNC_PLUG when writing synchronous revoke records
jbd2: use SWRITE_SYNC_PLUG when writing synchronous revoke records
ext4: really print the find_group_flex fallback warning only once
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
USB: pwc : do not pass stack allocated buffers to USB core.
USB: otg: Fix bug on remove path without transceiver
USB: correct error handling in cdc-wdm
USB: removal of tty->low_latency hack dating back to the old serial code
USB: serial: sierra driver bug fix for composite interface
USB: gadget: omap_udc uses platform_driver_probe()
USB: ci13xxx_udc: fix build error
USB: musb: Prevent multiple includes of musb.h
USB: pass mem_flags to dma_alloc_coherent
USB: g_file_storage: fix use-after-free bug when closing files
USB: ehci-sched.c: EHCI SITD scheduling bugfix
USB: fix mos7840 problem with minor numbers
USB: mos7840: add new device id
USB: musb: fix build when !CONFIG_PM
USB: musb: Remove my email address from few musb related drivers
USB: Gadget: MIPS CI13xxx UDC bugfixes
USB: Unusual Device support for Gold MP3 Player Energy
USB: serial: fix lifetime and locking problems
This patch adds missing role attribute to the DCCP type, otherwise
the creation of entries is not of any use.
The attribute added is CTA_PROTOINFO_DCCP_ROLE which contains the
role of the conntrack original tuple.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
cfq-iosched: cache prio_tree root in cfqq->p_root
cfq-iosched: fix bug with aliased request and cooperation detection
cfq-iosched: clear ->prio_trees[] on cfqd alloc
block: fix intermittent dm timeout based oops
umem: fix request_queue lock warning
block: simplify I/O stat accounting
pktcdvd.h should include mempool.h
cfq-iosched: use the default seek distance when there aren't enough seek samples
cfq-iosched: make seek_mean converge more quickly
block: make blk_abort_queue() ignore non-request based devices
block: include empty disks in /proc/diskstats
bio: use bio_kmalloc() in copy/map functions
bio: fix bio_kmalloc()
block: fix queue bounce limit setting
block: fix SG_IO vector request data length handling
scatterlist: make sure sg_miter_next() doesn't return 0 sized mappings
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (94 commits)
netfilter: ctnetlink: fix gcc warning during compilation
net/netrom: Fix socket locking
netlabel: Always remove the correct address selector
ucc_geth.c: Fix upsmr setting in RMII mode
8139too: fix HW initial flow
af_iucv: Fix race when queuing incoming iucv messages
af_iucv: Test additional sk states in iucv_sock_shutdown
af_iucv: Reject incoming msgs if RECV_SHUTDOWN is set
af_iucv: fix oops in iucv_sock_recvmsg() for MSG_PEEK flag
af_iucv: consider state IUCV_CLOSING when closing a socket
iwlwifi: DMA fixes
iwlwifi: add debugging for TX path
mwl8: fix build warning.
mac80211: fix alignment calculation bug
mac80211: do not print WARN if config interface
iwl3945: use cancel_delayed_work_sync to cancel rfkill_poll
iwlwifi: fix EEPROM validation mask to include OTP only devices
atmel: fix netdev ops conversion
pcnet_cs: add cis(firmware) of the Allied Telesis LA-PCM
mlx4_en: Fix cleanup if workqueue create in mlx4_en_add() fails
...
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
powerpc: Fix modular build of ide-pmac when mediabay is built in
powerpc/pasemi: Fix build error on UP
powerpc: Make macintosh/mediabay driver depend on CONFIG_BLOCK
maintainers: Fix PS3 patterns
powerpc/ps3: Fix CONFIG_PS3_FLASH=n build warning
powerpc/32: Don't clobber personality flags on exec
powerpc: Fix crash on CPU hotplug
powerpc/85xx: Remove defconfigs that mpc85xx_{smp_}defconfig cover
powerpc/85xx: Added SMP defconfig
powerpc/85xx: Enabled a bunch of FSL specific drivers/options
powerpc/85xx: Updated generic mpc85xx_defconfig
powerpc: don't disable SATA interrupts on Freescale MPC8610 HPCD
fsl_rio: Pass the proper device to dma mapping routines
powerpc: Fix of_node_put() exit path in of_irq_map_one()
powerpc/5200: defconfig updates
powerpc/5200: Add FLASH nodes to lite5200 device tree
powerpc/device-tree: Document MTD nodes with multiple "reg" tuples
powerpc/of-device-tree: Factor MTD physmap bindings out of booting-without-of
powerpc/5200: Bring the legacy fsl_spi_platform_data hooks back
This simplifies I/O stat accounting switching code and separates it
completely from I/O scheduler switch code.
Requests are accounted according to the state of their request queue
at the time of the request allocation. There is no need anymore to
flush the request queue when switching I/O accounting state.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Fix this build error:
In file included from fs/compat_ioctl.c:104:
include/linux/pktcdvd.h:285: error: expected specifier-qualifier-list before 'mempool_t'
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Add #ifndef to musb header file to prevent multiple inclusions.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Finds the first set bit in a 64 bit word. This is required in order
to fix a bug in GFS2, but I think it should be a generic function
in case of future users.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Willy Tarreau <w@1wt.eu>
Linux-2.6.29 deleted the legacy ACPI idle handler, leaving
the CPU_IDLE handler, which does not track bus master activity.
So delete the unused bm_activity field -- it is confusing to
print an always zero value.
This patch could break programs that parse
/proc/acpi/processor/*/power, since it deletes this
line from that file:
bus master activity: 00000000
http://bugzilla.kernel.org/show_bug.cgi?id=13145
is not fixed by this patch, but provoked this patch.
Signed-off-by: Len Brown <len.brown@intel.com>
PCIe 1.1 base neither requires the endpoint to implement the entire
PCIe capability structure nor specifies default values of registers
that are not implemented by the device. So we only save and restore
registers that must be implemented by different device types if the
device PCIe capability version is 1.
PCIe 1.1 Capability Structure Expansion ECN and PCIe 2.0 requires
all registers in the PCIe capability to be either implemented or
hardwired to 0. Their PCIe capability version is 2.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When checking for overlapping slots on registration of a new one, kvm
currently also considers zero-length (ie. deleted) slots and rejects
requests incorrectly. This finally denies user space from joining slots.
Fix the check by skipping deleted slots and advertise this via a
KVM_CAP_JOIN_MEMORY_REGIONS_WORKS.
Cc: stable@kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
/proc/diskstats used to show stats for all disks whether they're
zero-sized or not and their non-zero partitions. Commit
074a7aca7a accidentally changed the
behavior such that it doesn't print out zero sized disks. This patch
implements DISK_PITER_INCL_EMPTY_PART0 flag to partition iterator and
uses it in diskstats_show() such that empty part0 is shown in
/proc/diskstats.
Reported and bisectd by Dianel Collins.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Daniel Collins <solemnwarning@solemnwarning.no-ip.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Impact: fix bio_kmalloc() and its destruction path
bio_kmalloc() was broken in two ways.
* bvec_alloc_bs() first allocates bvec using kmalloc() and then
ignores it and allocates again like non-kmalloc bvecs.
* bio_kmalloc_destructor() didn't check for and free bio integrity
data.
This patch fixes the above problems. kmalloc patch is separated out
from bio_alloc_bioset() and allocates the requested number of bvecs as
inline bvecs.
* bio_alloc_bioset() no longer takes NULL @bs. None other than
bio_kmalloc() used it and outside users can't know how it was
allocated anyway.
* Define and use BIO_POOL_NONE so that pool index check in
bvec_free_bs() triggers if inline or kmalloc allocated bvec gets
there.
* Relocate destructors on top of each allocation function so that how
they're used is more clear.
Jens Axboe suggested allocating bvecs inline.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
There is currently only one way for userspace to say "wait for my storage
device to get ready for the modules I just loaded": to load the
scsi_wait_scan module. Expectations of userspace are that once this
module is loaded, all the (storage) devices for which the drivers
were loaded before the module load are present.
Now, there are some issues with the implementation, and the async
stuff got caught in the middle of this: The existing code only
waits for the scsy async probing to finish, but it did not take
into account at all that probing might not have begun yet.
(Russell ran into this problem on his computer and the fix works for him)
This patch fixes this more thoroughly than the previous "fix", which
had some bad side effects (namely, for kernel code that wanted to wait for
the scsi scan it would also do an async sync, which would deadlock if you did
it from async context already.. there's a report about that on lkml):
The patch makes the module first wait for all device driver probes, and then it
will wait for the scsi parallel scan to finish.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a comment typo in slow-work.h
...a trivial mistake, but it will mess up kerneldoc if nothing else.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Collect the DECLARE/DEFINE declarations together in linux/percpu-defs.h so
that they're in one place, and give them descriptive comments, particularly
the SHARED_ALIGNED variant.
It would be nice to collect these in linux/percpu.h, but that's not possible
without sorting out the severe #include recursion between the x86 arch headers
and the general headers (and possibly other arches too).
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
