David Miller reported soft lockup false-positives that trigger
on NOHZ due to CPUs idling for more than 10 seconds.
The solution is touch the softlockup watchdog when we return from
idle. (by definition we are not 'locked up' when we were idle)
http://bugzilla.kernel.org/show_bug.cgi?id=9409
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/net-2.6: (41 commits)
[XFRM]: Fix leak of expired xfrm_states
[ATM]: [he] initialize lock and tasklet earlier
[IPV4]: Remove bogus ifdef mess in arp_process
[SKBUFF]: Free old skb properly in skb_morph
[IPV4]: Fix memory leak in inet_hashtables.h when NUMA is on
[IPSEC]: Temporarily remove locks around copying of non-atomic fields
[TCP] MTUprobe: Cleanup send queue check (no need to loop)
[TCP]: MTUprobe: receiver window & data available checks fixed
[MAINTAINERS]: tlan list is subscribers-only
[SUNRPC]: Remove SPIN_LOCK_UNLOCKED
[SUNRPC]: Make xprtsock.c:xs_setup_{udp,tcp}() static
[PFKEY]: Sending an SADB_GET responds with an SADB_GET
[IRDA]: Compilation for CONFIG_INET=n case
[IPVS]: Fix compiler warning about unused register_ip_vs_protocol
[ARP]: Fix arp reply when sender ip 0
[IPV6] TCPMD5: Fix deleting key operation.
[IPV6] TCPMD5: Check return value of tcp_alloc_md5sig_pool().
[IPV4] TCPMD5: Use memmove() instead of memcpy() because we have overlaps.
[IPV4] TCPMD5: Omit redundant NULL check for kfree() argument.
ieee80211: Stop net_ratelimit/IEEE80211_DEBUG_DROP log pollution
...
* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
x86: fix APIC related bootup crash on Athlon XP CPUs
time: add ADJ_OFFSET_SS_READ
x86: export the symbol empty_zero_page on the 32-bit x86 architecture
x86: fix kprobes_64.c inlining borkage
pci: use pci=bfsort for HP DL385 G2, DL585 G2
x86: correctly set UTS_MACHINE for "make ARCH=x86"
lockdep: annotate do_debug() trap handler
x86: turn off iommu merge by default
x86: fix ACPI compile for LOCAL_APIC=n
x86: printk kernel version in WARN_ON and other dump_stack users
ACPI: Set max_cstate to 1 for early Opterons.
x86: fix NMI watchdog & 'stopped time' problem
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
virtio: fix net driver loop case where we fail to restart
module: fix and elaborate comments
virtio: fix module/device unloading
lguest: Fix uninitialized members in example launcher
increase the default minimum granularity some more - this gives us
more performance in aim7 benchmarks.
also correct some comments: we scale with ilog(ncpus) + 1.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The commit
commit 5cb350baf5
Author: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Date: Mon Oct 15 17:00:14 2007 +0200
sched: group scheduling, sysfs tunables
introduced the uids_mutex and the helpers to lock/unlock it.
Unfortunately, the error paths of alloc_uid() were not patched
to unlock it.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Michael Kerrisk reported that a long standing bug in the adjtimex()
system call causes glibc's adjtime(3) function to deliver the wrong
results if 'delta' is NULL.
add the ADJ_OFFSET_SS_READ API detail, which will be used by glibc
to fix this API compatibility bug.
Also see: http://bugzilla.kernel.org/show_bug.cgi?id=6761
[ mingo@elte.hu: added patch description and made it backwards compatible ]
NOTE: the new flag is defined 0xa001 so that it returns -EINVAL on
older kernels - this way glibc can use it safely. Suggested by Ulrich
Drepper.
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Remove binary sysctls that never worked due to missing strategy functions.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove binary sysctls that never worked due to missing strategy functions.
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Switch the remaining IPVS sysctl entries over to to use CTL_UNNUMBERED,
I stronly doubt that anyone is using the sys_sysctl interface to
these variables.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
sysctl table check failed: /net/ipv4/vs/lblc_expiration .3.5.21.19 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/lblcr_expiration .3.5.21.20 Missing strategy
Switch these entried over to use CTL_UNNUMBERED as clearly
the sys_syscal portion wasn't working.
This is along the same lines as Christian Borntraeger's patch that fixes
up entries with no stratergy in net/ipv4/ipvs/ip_vs_ctl.c
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Running the latest git code I get the following messages during boot:
sysctl table check failed: /net/ipv4/vs/drop_entry .3.5.21.4 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/drop_packet .3.5.21.5 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/secure_tcp .3.5.21.6 Missing strategy
[...]
sysctl table check failed: /net/ipv4/vs/sync_threshold .3.5.21.24 Missing strategy
I removed the binary sysctl handler for those messages and also removed
the definitions in ip_vs.h. The alternative would be to implement a
proper strategy handler, but syscall sysctl is deprecated.
There are other sysctl definitions that are commented out or work with
the default sysctl_data strategy. I did not touch these.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix a typo in ntp.c that has caused updating of the persistent (RTC)
clock when synced to NTP to behave erratically.
When debugging a freeze that arises on my AMD64 machines when I
run the ntpd service, I added a number of printk's to monitor the
sync_cmos_clock procedure. I discovered that it was not syncing to
cmos RTC every 11 minutes as documented, but instead would keep trying
every second for hours at a time. The reason turned out to be a typo
in sync_cmos_clock, where it attempts to ensure that
update_persistent_clock is called very close to 500 msec. after a 1
second boundary (required by the PC RTC's spec). That typo referred to
"xtime" in one spot, rather than "now", which is derived from "xtime"
but not equal to it. This makes the test erratic, creating a
"coin-flip" that decides when update_persistent_clock is called - when
it is called, which is rarely, it may be at any time during the one
second period, rather than close to 500 msec, so the value written is
needlessly incorrect, too.
Signed-off-by: David P. Reed
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
dont use the vgetcpu tcache - it's causing problems with tasks
migrating, they'll see the old cache up to a jiffy after the
migration, further increasing the costs of the migration.
In the worst case they see a complete bogus information from
the tcache, when a sys_getcpu() call "invalidated" the cache
info by incrementing the jiffies _and_ the cpuid info in the
cache and the following vdso_getcpu() call happens after
vdso_jiffies have been incremented.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
cpu_down() code is ok wrt sched_idle_next() placing the 'idle' task not
at the beginning of the queue.
So get rid of activate_idle_task() and make use of activate_task() instead.
It is the same as activate_task(), except for the update_rq_clock(rq) call
that is redundant.
Code size goes down:
text data bss dec hex filename
47853 3934 336 52123 cb9b sched.o.before
47828 3934 336 52098 cb82 sched.o.after
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Grant Wilson has reported rare SCHED_FAIR_USER crashes on his quad-core
system, which crashes can only be explained via runqueue corruption.
there is a narrow SMP race in __set_task_cpu(): after ->cpu is set up to
a new value, task_rq_lock(p, ...) can be successfuly executed on another
CPU. We must ensure that updates of per-task data have been completed by
this moment.
this bug has been hiding in the Linux scheduler for an eternity (we never
had any explicit barrier for task->cpu in set_task_cpu() - so the bug was
introduced in 2.5.1), but only became visible via set_task_cfs_rq() being
accidentally put after the task->cpu update. It also probably needs a
sufficiently out-of-order CPU to trigger.
Reported-by: Grant Wilson <grant.wilson@zen.co.uk>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Suppose that the SCHED_FIFO task does
switch_uid(new_user);
Now, p->se.cfs_rq and p->se.parent both point into the old
user_struct->tg because sched_move_task() doesn't call set_task_cfs_rq()
for !fair_sched_class case.
Suppose that old user_struct/task_group is freed/reused, and the task
does
sched_setscheduler(SCHED_NORMAL);
__setscheduler() sets fair_sched_class, but doesn't update
->se.cfs_rq/parent which point to the freed memory.
This means that check_preempt_wakeup() doing
while (!is_same_group(se, pse)) {
se = parent_entity(se);
pse = parent_entity(pse);
}
may OOPS in a similar way if rq->curr or p did something like above.
Perhaps we need something like the patch below, note that
__setscheduler() can't do set_task_cfs_rq().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently the scheduler checks for PF_VCPU to decide if this timeslice
has to be accounted as guest time. On s390 host interrupts are not
disabled during guest execution. This causes theses interrupts to be
accounted as guest time if CONFIG_VIRT_CPU_ACCOUNTING is set. Solution
is to check if an interrupt triggered account_system_time. As the tick
is timer interrupt based, we have to subtract hardirq_offset.
I tested the patch on s390 with CONFIG_VIRT_CPU_ACCOUNTING and on
x86_64. Seems to work.
CC: Avi Kivity <avi@qumranet.com>
CC: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The original meaning of the old test (p->state > TASK_STOPPED) was
"not dead", since it was before TASK_TRACED existed and before the
state/exit_state split. It was a wrong correction in commit
14bf01bb05 to make this test for
TASK_TRACED instead. It should have been changed when TASK_TRACED
was introducted and again when exit_state was introduced.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Kees Cook <kees@ubuntu.com>
Acked-by: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[NET]: rt_check_expire() can take a long time, add a cond_resched()
[ISDN] sc: Really, really fix warning
[ISDN] sc: Fix sndpkt to have the correct number of arguments
[TCP] FRTO: Clear frto_highmark only after process_frto that uses it
[NET]: Remove notifier block from chain when register_netdevice_notifier fails
[FS_ENET]: Fix module build.
[TCP]: Make sure write_queue_from does not begin with NULL ptr
[TCP]: Fix size calculation in sk_stream_alloc_pskb
[S2IO]: Fixed memory leak when MSI-X vector allocation fails
[BONDING]: Fix resource use after free
[SYSCTL]: Fix warning for token-ring from sysctl checker
[NET] random : secure_tcp_sequence_number should not assume CONFIG_KTIME_SCALAR
[IWLWIFI]: Not correctly dealing with hotunplug.
[TCP] FRTO: Plug potential LOST-bit leak
[TCP] FRTO: Limit snd_cwnd if TCP was application limited
[E1000]: Fix schedule while atomic when called from mii-tool.
[NETX]: Fix build failure added by 2.6.24 statistics cleanup.
[EP93xx_ETH]: Build fix after 2.6.24 NAPI changes.
[PKT_SCHED]: Check subqueue status before calling hard_start_xmit
We'd better not nlmsg_free on a pointer containing an undefined value
(and without having anything allocated).
Spotted by the Coverity checker.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lockdep reports a circular locking dependency in the hibernate code
because
- during system boot hibernate code (from an initcall) locks pm_mutex
and then a sysfs buffer mutex via name_to_dev_t
- during regular operation hibernate code locks pm_mutex under a
sysfs buffer mutex because it's called from sysfs methods.
The deadlock can never happen because during initcall invocation nothing
can write to sysfs yet. This removes the lockdep report by marking the
initcall locking as being in a different class.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In __do_IRQ(), the normal case is that IRQ_DISABLED is checked and if set
the handler (handle_IRQ_event()) is not called.
Earlier in __do_IRQ(), if IRQ_PER_CPU is set the code does not check
IRQ_DISABLED and calls the handler even though IRQ_DISABLED is set. This
behavior seems unintentional.
One user encountering this behavior is the CPE handler (in
arch/ia64/kernel/mca.c). When the CPE handler encounters too many CPEs
(such as a solid single bit error), it sets up a polling timer and disables
the CPE interrupt (to avoid excessive overhead logging the stream of single
bit errors). disable_irq_nosync() is called which sets IRQ_DISABLED. The
IRQ_PER_CPU flag was previously set (in ia64_mca_late_init()). The net
result is the CPE handler gets called even though it is marked disabled.
If the behavior of not checking IRQ_DISABLED when IRQ_PER_CPU is set is
intentional, it would be worthy of a comment describing the intended
behavior. disable_irq_nosync() does call chip->disable() to provide a
chipset specifiec interface for disabling the interrupt, which avoids this
issue when used.
Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is my trivial patch to swat innumerable little bugs with a single
blow.
After some intensive review (my apologies for not having gotten to this
sooner) what we have looks like a good base to build on with the current
pid namespace code but it is not complete, and it is still much to simple
to find issues where the kernel does the wrong thing outside of the initial
pid namespace.
Until the dust settles and we are certain we have the ABI and the
implementation is as correct as humanly possible let's keep process ID
namespaces behind CONFIG_EXPERIMENTAL.
Allowing us the option of fixing any ABI or other bugs we find as long as
they are minor.
Allowing users of the kernel to avoid those bugs simply by ensuring their
kernel does not have support for multiple pid namespaces.
[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kir Kolyshkin <kir@swsoft.com>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit faf8c714f4 caused a regression:
parameter names longer than MAX_KBUILD_MODNAME will now be rejected,
although we just need to keep the module name part that short. This patch
restores the old behaviour while still avoiding that memchr is called with
its length parameter larger than the total string length.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Upon module load, we must take the markers mutex. It implies that the marker
mutex must be nested inside the module mutex.
It implies changing the nesting order : now the marker mutex nests inside the
module mutex. Make the necessary changes to reverse the order in which the
mutexes are taken.
Includes some cleanup from Dave Hansen <haveblue@us.ibm.com>.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert 62d0df6406.
This was originally intended as a simple initial example of how to create a
control groups subsystem; it wasn't intended for mainline, but I didn't make
this clear enough to Andrew.
The CFS cgroup subsystem now has better functionality for the per-cgroup usage
accounting (based directly on CFS stats) than the "usage" status file in this
patch, and the "load" status file is rather simplistic - although having a
per-cgroup load average report would be a useful feature, I don't believe this
patch actually provides it. If it gets into the final 2.6.24 we'd probably
have to support this interface for ever.
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
i386 and x86-64 registers System RAM as IORESOURCE_MEM | IORESOURCE_BUSY.
But ia64 registers it as IORESOURCE_MEM only.
In addition, memory hotplug code registers new memory as IORESOURCE_MEM too.
This difference causes a failure of memory unplug of x86-64. This patch
fixes it.
This patch adds IORESOURCE_BUSY to avoid potential overlap mapping by PCI
device.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Luck, Tony" <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I boot with the 'quiet' parameter, I see on the screen:
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 39.036026] Initializing cgroup subsys cpuacct
[ 39.036080] Initializing cgroup subsys debug
[ 39.036118] Initializing cgroup subsys ns
This patch lowers the priority of those messages, adds a "cgroup: " prefix
to another couple of printks and kills the useless reference to the source
file.
Signed-off-by: Diego Calleja <diegocg@gmail.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Original patch assumed args->nlen < CTL_MAXNAME, but it can be false.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As seen when booting ppc64_defconfig:
sysctl table check failed: /net/token-ring .3.14 procname does not match binary path procname
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
While a signal is blocked, it must be posted even if its action is
SIG_IGN or is SIG_DFL with the default action to ignore. This works
right most of the time, but is broken when a sigwait (rt_sigtimedwait)
is in progress. This changes the early-discard check to respect
real_blocked. ~blocked is the set to check for "should wake up now",
but ~(blocked|real_blocked) is the set for "blocked" semantics as
defined by POSIX.
This fixes bugzilla entry 9347, see
http://bugzilla.kernel.org/show_bug.cgi?id=9347
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
compat_exit_robust_list() computes a pointer to the
futex entry in userspace as follows:
(void __user *)entry + futex_offset
'entry' is a 'struct robust_list __user *', and
'futex_offset' is a 'compat_long_t' (typically a 's32').
Things explode if the 32-bit sign bit is set in futex_offset.
Type promotion sign extends futex_offset to a 64-bit value before
adding it to 'entry'.
This triggered a problem on sparc64 running 32-bit applications which
would lock up a cpu looping forever in the fault handling for the
userspace load in handle_futex_death().
Compat userspace runs with address masking (wherein the cpu zeros out
the top 32-bits of every effective address given to a memory operation
instruction) so the sparc64 fault handler accounts for this by
zero'ing out the top 32-bits of the fault address too.
Since the kernel properly uses the compat_uptr interfaces, kernel side
accesses to compat userspace work too since they will only use
addresses with the top 32-bit clear.
Because of this compat futex layer bug we get into the following loop
when executing the get_user() load near the top of handle_futex_death():
1) load from address '0xfffffffff7f16bd8', FAULT
2) fault handler clears upper 32-bits, processes fault
for address '0xf7f16bd8' which succeeds
3) goto #1
I want to thank Bernd Zeimetz, Josip Rodin, and Fabio Massimo Di Nitto
for their tireless efforts helping me track down this bug.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds a proper prototype for migration_init() in
include/linux/sched.h
Since there's no point in always returning 0 to a caller that doesn't check
the return value it also changes the function to return void.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
SMP balancing is done with IRQs disabled and can iterate the full rq.
When rqs are large this can cause large irq-latencies. Limit the nr of
iterations on each run.
This fixes a scheduling latency regression reported by the -rt folks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Sukadev Bhattiprolu reported a kernel crash with control groups.
There are couple of problems discovered by Suka's test:
- The test requires the cgroup filesystem to be mounted with
atleast the cpu and ns options (i.e both namespace and cpu
controllers are active in the same hierarchy).
# mkdir /dev/cpuctl
# mount -t cgroup -ocpu,ns none cpuctl
(or simply)
# mount -t cgroup none cpuctl -> Will activate all controllers
in same hierarchy.
- The test invokes clone() with CLONE_NEWNS set. This causes a a new child
to be created, also a new group (do_fork->copy_namespaces->ns_cgroup_clone->
cgroup_clone) and the child is attached to the new group (cgroup_clone->
attach_task->sched_move_task). At this point in time, the child's scheduler
related fields are uninitialized (including its on_rq field, which it has
inherited from parent). As a result sched_move_task thinks its on
runqueue, when it isn't.
As a solution to this problem, I moved sched_fork() call, which
initializes scheduler related fields on a new task, before
copy_namespaces(). I am not sure though whether moving up will
cause other side-effects. Do you see any issue?
- The second problem exposed by this test is that task_new_fair()
assumes that parent and child will be part of the same group (which
needn't be as this test shows). As a result, cfs_rq->curr can be NULL
for the child.
The solution is to test for curr pointer being NULL in
task_new_fair().
With the patch below, I could run ns_exec() fine w/o a crash.
Reported-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
clean up the preemption check to not use unnecessary 64-bit
variables. This improves code size:
text data bss dec hex filename
44227 3326 36 47589 b9e5 sched.o.before
44201 3326 36 47563 b9cb sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
wakeup preemption fix: do not make it dependent on p->prio.
Preemption purely depends on ->vruntime.
This improves preemption in mixed-nice-level workloads.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
remove PREEMPT_RESTRICT. (this is a separate commit so that any
regression related to the removal itself is bisectable)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
PREEMPT_RESTRICT was a method aimed at reducing the amount of wakeup
related preemption. It has a disadvantage though, it can prevent
legitimate wakeups if a task is 'unlucky' to be hit too early by a tick
that clears peer_preempt.
Now that the wakeup preemption has been cleaned up we dont seem to have
excessive preemptions anymore, so this feature can be turned off. (and
removed in the next patch)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1) hardcoded 1000000000 value is used five times in places where
NSEC_PER_SEC might be more readable.
2) A conversion from nsec to msec uses the hardcoded 1000000 value,
which is a candidate for NSEC_PER_MSEC.
no code changed:
text data bss dec hex filename
44359 3326 36 47721 ba69 sched.o.before
44359 3326 36 47721 ba69 sched.o.after
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Yanmin Zhang reported an aim7 regression and bisected it down to:
| commit 38ad464d41
| Author: Ingo Molnar <mingo@elte.hu>
| Date: Mon Oct 15 17:00:02 2007 +0200
|
| sched: uniform tunings
|
| use the same defaults on both UP and SMP.
fix this by reintroducing similar SMP tunings again. This resolves
the regression.
(also update the comments to match the ilog2(nr_cpus) tuning effect)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the
deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been
broken on powerpc, because we end up counting user time twice: once in
timer_interrupt() and once in update_process_times().
This fixes the problem by pulling the code in update_process_times
that updates utime and stime into a separate function called
account_process_tick. If CONFIG_VIRT_CPU_ACCOUNTING is not defined,
there is a version of account_process_tick in kernel/timer.c that
simply accounts a whole tick to either utime or stime as before. If
CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to
implement account_process_tick.
This also lets us simplify the s390 code a bit; it means that the s390
timer interrupt can now call update_process_times even when
CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a
suitable account_process_tick().
account_process_tick() now takes the task_struct * as an argument.
Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the delay accounting regression introduced by commit
75d4ef16a6. rq no longer has sched_info
data associated with it. task_struct sched_info structure is used by delay
accounting to provide back statistics to user space.
also remove direct use of sched_clock() (which is not a valid thing to
do anymore) and use rq->clock instead.
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
we lost the sched_min_granularity tunable to a clever optimization
that uses the sched_latency/min_granularity ratio - but the ratio
is quite unintuitive to users and can also crash the kernel if the
ratio is set to 0. So reintroduce the min_granularity tunable,
while keeping the ratio maintained internally.
no functionality changed.
[ mingo@elte.hu: some fixlets. ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a few comments to place_entity(). No code changed.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
vslice was missing a factor NICE_0_LOAD, as weight is in
weight*NICE_0_LOAD units.
the effect of this bug was larger initial slices and
thus latency-noisier forks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's make immediately obvious from where sysctl comes from and messages
itself more noticeable.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following functions can now become static again:
- get_futex_key()
- get_futex_key_refs()
- drop_futex_key_refs()
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Do not allow processes to clear their TIF_SIGPENDING if TIF_FREEZE is set,
so that they will not race with the freezer (like mysqld does, for example).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@suspend2.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fix style of swap() macro in kernel/sched_fair.c.
( this macro should eventually move to a general header, as ext3 uses
a similar construct too. )
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Adds a cpu.usage file to the CFS cgroup that reports CPU usage in
milliseconds for that cgroup's tasks
[ mingo@elte.hu: style cleanups. ]
Signed-off-by: Paul Menage <menage@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Peter Zijlstra noticed that the rcu_head object need not be present
in every cfs_rq of a group. Move it to the task_group structure
instead.
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch:
commit 9b5b77512d
Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Date: Mon Oct 15 17:00:09 2007 +0200
sched: clean up code under CONFIG_FAIR_GROUP_SCHED
Introduced an assumption of the existence of CPU0 via this line
cfs_rq = tg->cfs_rq[0];
If you have no CPU0, that will be NULL. The fix seems to be just to
take whatever cfs_rq queue comes out of the for_each_possible_cpu()
loop, since they're all equally good for the destruction operation.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
keep utime/stime monotonic.
cpustats use utime/stime as a ratio against sum_exec_runtime, as a
consequence it can happen - when the ratio changes faster than time
accumulates - that either can be appear to go backwards.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Don't undef __i386__/__x86_64__ in uml anymore, make sure that (few) places
that required adjusting the ifdefs got those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the hrtimer printk "Switched to high resolution mode .." to
be KERN_DEBUG, rather than KERN_INFO. If users need to see this they
can pass "loglevel" or "debug" on the command line, or check dmesg.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kernel/hrtimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
This makes sure printk format strings contain no more than a single
line.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch removes the unused
EXPORT_SYMBOL_GPL(tick_nohz_get_sleep_length).
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix a typo in the __lock_acquire comment.
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At the moment, a lot of load balancing code that is irrelevant to non
SMP systems gets included during non SMP builds.
This patch addresses this issue and reduces the binary size on non
SMP systems:
text data bss dec hex filename
10983 28 1192 12203 2fab sched.o.before
10739 28 1192 11959 2eb7 sched.o.after
Signed-off-by: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At the moment, balance_tasks() provides low level functionality for both
move_tasks() and move_one_task() (indirectly) via the load_balance()
function (in the sched_class interface) which also provides dual
functionality. This dual functionality complicates the interfaces and
internal mechanisms and makes the run time overhead of operations that
are called with two run queue locks held.
This patch addresses this issue and reduces the overhead of these
operations.
Signed-off-by: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- replace "cont" with "cgrp" in a few places in the CFS cgroup code,
- use write_uint rather than write for cpu.shares write function
Signed-off-by: Paul Menage <menage@google.com>
Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
profile=sleep only works if CONFIG_SCHEDSTATS is set. This patch notes
the limitation in Documentation/kernel-parameters.txt and prints a
warning at boot-time if profile=sleep is used without CONFIG_SCHEDSTAT.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
A full register dump along with stack backtrace would make the
"scheduling while atomic" message more helpful. Use show_regs() instead
of dump_stack() for this. We already know we're atomic in here (that is
why this function was called) so show_regs()'s atomicity expectations
are guaranteed.
Also, modify the output of the "BUG: scheduling while atomic:" header a
bit to keep task->comm and task->pid together and preempt_count() after
them.
Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
clean up sched_domain_debug().
this also shrinks the code a bit:
text data bss dec hex filename
50474 4306 480 55260 d7dc sched.o.before
50404 4306 480 55190 d796 sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jeff Dike noticed that wait_for_completion_interruptible()'s prototype
had a mismatched fastcall.
Fix this by removing the fastcall attributes from all the completion APIs.
Found-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
commit 029190c515 (cpuset
sched_load_balance flag) was not tested SCHED_DEBUG enabled as
committed as it dereferences NULL when used and it reordered
the sysctl registration to cause it to never show any domains
or their tunables.
Fixes:
1) restore arch_init_sched_domains ordering
we can't walk the domains before we build them
presently we register cpus with empty directories (no domain
directories or files).
2) make unregister_sched_domain_sysctl do nothing when already unregistered
detach_destroy_domains is now called one set of cpus at a time
unregister_syctl dereferences NULL if called with a null.
While the the function would always dereference null if called
twice, in the previous code it was always called once and then
was followed a register. So only the hidden bug of the
sysctl_root_table not being allocated followed by an attempt to
free it would have shown the error.
3) always call unregister and register in partition_sched_domains
The code is "smart" about unregistering only needed domains.
Since we aren't guaranteed any calls to unregister, always
unregister. Without calling register on the way out we
will not have a table or any sysctl tree.
4) warn if register is called without unregistering
The previous table memory is lost, leaving pointers to the
later freed memory in sysctl and leaking the memory of the
tables.
Before this patch on a 2-core 4-thread box compiled for SMT and NUMA,
the domains appear empty (there are actually 3 levels per cpu). And as
soon as two domains a null pointer is dereferenced (unreliable in this
case is stack garbage):
bu19a:~# ls -R /proc/sys/kernel/sched_domain/
/proc/sys/kernel/sched_domain/:
cpu0 cpu1 cpu2 cpu3
/proc/sys/kernel/sched_domain/cpu0:
/proc/sys/kernel/sched_domain/cpu1:
/proc/sys/kernel/sched_domain/cpu2:
/proc/sys/kernel/sched_domain/cpu3:
bu19a:~# mkdir /dev/cpuset
bu19a:~# mount -tcpuset cpuset /dev/cpuset/
bu19a:~# cd /dev/cpuset/
bu19a:/dev/cpuset# echo 0 > sched_load_balance
bu19a:/dev/cpuset# mkdir one
bu19a:/dev/cpuset# echo 1 > one/cpus
bu19a:/dev/cpuset# echo 0 > one/sched_load_balance
Unable to handle kernel paging request for data at address 0x00000018
Faulting instruction address: 0xc00000000006b608
NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000
REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml)
MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000
DAR: 0000000000000018, DSISR: 0000000040000000
TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2
..
NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110
LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110
Call Trace:
[c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable)
[c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0
[c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230
[c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0
[c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170
[c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820
[c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180
[c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0
[c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90
[c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As it is some callers of synchronize_irq rely on memory barriers
to provide synchronisation against the IRQ handlers. For example,
the tg3 driver does
tp->irq_sync = 1;
smp_mb();
synchronize_irq();
and then in the IRQ handler:
if (!tp->irq_sync)
netif_rx_schedule(dev, &tp->napi);
Unfortunately memory barriers only work well when they come in
pairs. Because we don't actually have memory barriers on the
IRQ path, the memory barrier before the synchronize_irq() doesn't
actually protect us.
In particular, synchronize_irq() may return followed by the
result of netif_rx_schedule being made visible.
This patch (mostly written by Linus) fixes this by using spin
locks instead of memory barries on the synchronize_irq() path.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kernel-doc for auditsc parameter changes.
Warning(linux-2.6.23-git17//kernel/auditsc.c:1623): No description found for parameter 'dentry'
Warning(linux-2.6.23-git17//kernel/auditsc.c:1666): No description found for parameter 'dentry'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
KVM: Use new smp_call_function_mask() in kvm_flush_remote_tlbs()
sched: don't clear PF_VCPU in scheduler
KVM: Improve local apic timer wraparound handling
KVM: Fix local apic timer divide by zero
KVM: Move kvm_guest_exit() after local_irq_enable()
KVM: x86 emulator: fix access registers for instructions with ModR/M byte and Mod = 3
KVM: VMX: Force vm86 mode if setting flags during real mode
KVM: x86 emulator: implement 'movnti mem, reg'
KVM: VMX: Reset mmu context when entering real mode
KVM: VMX: Handle NMIs before enabling interrupts and preemption
KVM: MMU: Set shadow pte atomically in mmu_pte_write_zap_pte()
KVM: x86 emulator: fix repne/repnz decoding
KVM: x86 emulator: fix merge screwup due to emulator split
Gabriel C reported that modprobing appletalk on current git gives a
warning in dmesg :
"sysctl table check failed: /net/appletalk .3.7 procname does not match binary path procname"
Oops. My apologies it appears I made a mistake when creating my table
to check up on sysctl values.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KVM clears it by itself now, and for s390 this is plain wrong.
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is. Limitations:
* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there. New command
tells audit to recalculate the trees, trimming such sources of false
positives.
Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (74 commits)
fix do_sys_open() prototype
sysfs: trivial: fix sysfs_create_file kerneldoc spelling mistake
Documentation: Fix typo in SubmitChecklist.
Typo: depricated -> deprecated
Add missing profile=kvm option to Documentation/kernel-parameters.txt
fix typo about TBI in e1000 comment
proc.txt: Add /proc/stat field
small documentation fixes
Fix compiler warning in smount example program from sharedsubtree.txt
docs/sysfs: add missing word to sysfs attribute explanation
documentation/ext3: grammar fixes
Documentation/java.txt: typo and grammar fixes
Documentation/filesystems/vfs.txt: typo fix
include/asm-*/system.h: remove unused set_rmb(), set_wmb() macros
trivial copy_data_pages() tidy up
Fix typo in arch/x86/kernel/tsc_32.c
file link fix for Pegasus USB net driver help
remove unused return within void return function
Typo fixes retrun -> return
x86 hpet.h: remove broken links
...
Weird I thought I had written the makefile so this would be handled. Oh
well this should fix it.
Sorry about that.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-and-tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the loop style of copy_data_pages() to remove a duplicate condition.
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Ingo Molnar