Commit Graph

20 Commits

Author SHA1 Message Date
Oleg Nesterov
ad133ba3dc sched, signals: fix the racy usage of ->signal in account_group_xxx/run_posix_cpu_timers
Impact: fix potential NULL dereference

Contrary to ad474caca3 changelog, other
acct_group_xxx() helpers can be called after exit_notify() by timer tick.
Thanks to Roland for pointing out this. Somehow I missed this simple fact
when I read the original patch, and I am afraid I confused Frank during
the discussion. Sorry.

Fortunately, these helpers work with current, we can check ->exit_state
to ensure that ->signal can't go away under us.

Also, add the comment and compiler barrier to account_group_exec_runtime(),
to make sure we load ->signal only once.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-17 16:49:35 +01:00
Linus Torvalds
88ed86fee6 Merge branch 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc
* 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: (35 commits)
  proc: remove fs/proc/proc_misc.c
  proc: move /proc/vmcore creation to fs/proc/vmcore.c
  proc: move pagecount stuff to fs/proc/page.c
  proc: move all /proc/kcore stuff to fs/proc/kcore.c
  proc: move /proc/schedstat boilerplate to kernel/sched_stats.h
  proc: move /proc/modules boilerplate to kernel/module.c
  proc: move /proc/diskstats boilerplate to block/genhd.c
  proc: move /proc/zoneinfo boilerplate to mm/vmstat.c
  proc: move /proc/vmstat boilerplate to mm/vmstat.c
  proc: move /proc/pagetypeinfo boilerplate to mm/vmstat.c
  proc: move /proc/buddyinfo boilerplate to mm/vmstat.c
  proc: move /proc/vmallocinfo to mm/vmalloc.c
  proc: move /proc/slabinfo boilerplate to mm/slub.c, mm/slab.c
  proc: move /proc/slab_allocators boilerplate to mm/slab.c
  proc: move /proc/interrupts boilerplate code to fs/proc/interrupts.c
  proc: move /proc/stat to fs/proc/stat.c
  proc: move rest of /proc/partitions code to block/genhd.c
  proc: move /proc/cpuinfo code to fs/proc/cpuinfo.c
  proc: move /proc/devices code to fs/proc/devices.c
  proc: move rest of /proc/locks to fs/locks.c
  ...
2008-10-23 12:04:37 -07:00
Linus Torvalds
133e887f90 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: disable the hrtick for now
  sched: revert back to per-rq vruntime
  sched: fair scheduler should not resched rt tasks
  sched: optimize group load balancer
  sched: minor fast-path overhead reduction
  sched: fix the wrong mask_len, cleanup
  sched: kill unused scheduler decl.
  sched: fix the wrong mask_len
  sched: only update rq->clock while holding rq->lock
2008-10-23 09:37:16 -07:00
Alexey Dobriyan
b5aadf7f14 proc: move /proc/schedstat boilerplate to kernel/sched_stats.h
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-23 18:06:12 +04:00
Peter Zijlstra
b968905292 sched: fix the wrong mask_len, cleanup
Clean up the division in show_schedstat().

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-17 13:05:22 +02:00
Miao Xie
c851c8676b sched: fix the wrong mask_len
If NR_CPUS isn't a multiple of 32, we get a truncated string of sched
domains by catting /proc/schedstat. This is caused by the wrong mask_len.

This patch fixes it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-17 12:26:33 +02:00
Frank Mayhar
7086efe1c1 timers: fix itimer/many thread hang, v3
- fix UP lockup
- another set of UP/SMP cleanups and simplifications

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-27 20:04:45 +02:00
Frank Mayhar
bb34d92f64 timers: fix itimer/many thread hang, v2
This is the second resubmission of the posix timer rework patch, posted
a few days ago.

This includes the changes from the previous resubmittion, which addressed
Oleg Nesterov's comments, removing the RCU stuff from the patch and
un-inlining the thread_group_cputime() function for SMP.

In addition, per Ingo Molnar it simplifies the UP code, consolidating much
of it with the SMP version and depending on lower-level SMP/UP handling to
take care of the differences.

It also cleans up some UP compile errors, moves the scheduler stats-related
macros into kernel/sched_stats.h, cleans up a merge error in
kernel/fork.c and has a few other minor fixes and cleanups as suggested
by Oleg and Ingo. Thanks for the review, guys.

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 13:38:44 +02:00
Ankita Garg
46ac22bab4 sched: fix accounting in task delay accounting & migration
On Thu, Jun 19, 2008 at 12:27:14PM +0200, Peter Zijlstra wrote:
> On Thu, 2008-06-05 at 10:50 +0530, Ankita Garg wrote:
>
> > Thanks Peter for the explanation...
> >
> > I agree with the above and that is the reason why I did not see weird
> > values with cpu_time. But, run_delay still would suffer skews as the end
> > points for delta could be taken on different cpus due to migration (more
> > so on RT kernel due to the push-pull operations). With the below patch,
> > I could not reproduce the issue I had seen earlier. After every dequeue,
> > we take the delta and start wait measurements from zero when moved to a
> > different rq.
>
> OK, so task delay delay accounting is broken because it doesn't take
> migration into account.
>
> What you've done is make it symmetric wrt enqueue, and account it like
>
>   cpu0      cpu1
>
> enqueue
>  <wait-d1>
> dequeue
>             enqueue
>              <wait-d2>
>             run
>
> Where you add both d1 and d2 to the run_delay,.. right?
>

Thanks for reviewing the patch. The above is exactly what I have done.

> This seems like a good fix, however it looks like the patch will break
> compilation in !CONFIG_SCHEDSTATS && !CONFIG_TASK_DELAY_ACCT, of it
> failing to provide a stub for sched_info_dequeue() in that case.

Fixed. Pl. find the new patch below.

Signed-off-by: Ankita Garg <ankita@in.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Gregory Haskins <ghaskins@novell.com>
Cc: rostedt@goodmis.org
Cc: suresh.b.siddha@intel.com
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: dhaval@linux.vnet.ibm.com
Cc: vatsa@linux.vnet.ibm.com
Cc: David Bahi <DBahi@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-04 12:50:23 +02:00
Bharath Ravi
d4abc238c9 sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue
This patch corrects the incorrect value of per process run-queue wait
time reported by delay statistics. The anomaly was due to the following
reason. When a process leaves the CPU and immediately starts waiting for
CPU on the runqueue (which means it remains in the TASK_RUNNABLE state),
the time of re-entry into the run-queue is never recorded. Due to this,
the waiting time on the runqueue from this point of re-entry upto the
next time it hits the CPU is not accounted for. This is solved by
recording the time of re-entry of a process leaving the CPU in the
sched_info_depart() function IF the process will go back to waiting on
the run-queue. This IF condition is verified by checking whether the
process is still in the TASK_RUNNABLE state.

The patch was tested on 2.6.26-rc6 using two simple CPU hog programs.
The values noted prior to the fix did not account for the time spent on
the runqueue waiting. After the fix, the correct values were reported
back to user space.

Signed-off-by: Bharath Ravi <bharathravi1@gmail.com>
Signed-off-by: Madhava K R  <madhavakr@gmail.com>
Cc: dhaval@linux.vnet.ibm.com
Cc: vatsa@in.ibm.com
Cc: balbir@in.ibm.com
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 14:15:28 +02:00
Adrian Bunk
c6fba5451a show_schedstat(): fix memleak
The Coverity checker spotted a memleak introduced by commit
39106dcf85 (cpumask: use new cpus_scnprintf
function).

It seems the kfree() got lost between v2 and v3 of this patch...

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-29 11:25:15 +02:00
Mike Travis
39106dcf85 cpumask: use new cpus_scnprintf function
* Cleaned up references to cpumask_scnprintf() and added new
    cpulist_scnprintf() interfaces where appropriate.

  * Fix some small bugs (or code efficiency improvments) for various uses
    of cpumask_scnprintf.

  * Clean up some checkpatch errors.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Ingo Molnar
f95e0d1c2a sched: clean up kernel/sched_stat.h
clean up kernel/sched_stat.h.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-28 15:52:56 +01:00
Balbir Singh
9a41785cc4 sched: fix delay accounting regression
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>
2007-11-09 22:39:37 +01:00
Ken Chen
480b9434c5 sched: reduce schedstat variable overhead a bit
schedstat is useful in investigating CPU scheduler behavior.  Ideally,
I think it is beneficial to have it on all the time.  However, the
cost of turning it on in production system is quite high, largely due
to number of events it collects and also due to its large memory
footprint.

Most of the fields probably don't need to be full 64-bit on 64-bit
arch.  Rolling over 4 billion events will most like take a long time
and user space tool can be made to accommodate that.  I'm proposing
kernel to cut back most of variable width on 64-bit system.  (note,
the following patch doesn't affect 32-bit system).

Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-18 21:32:56 +02:00
Ingo Molnar
2d72376b3a sched: clean up schedstats, cnt -> count
rename all 'cnt' fields and variables to the less yucky 'count' name.

yuckage noticed by Andrew Morton.

no change in code, other than the /proc/sched_debug bkl_count string got
a bit larger:

   text    data     bss     dec     hex filename
  38236    3506      24   41766    a326 sched.o.before
  38240    3506      24   41770    a32a sched.o.after

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Ingo Molnar
75d4ef16a6 sched: fix delay accounting performance regression
fix delay accounting performance regression - those sched_clock()
calls are not needed.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:08 +02:00
Ingo Molnar
c3c7011969 [PATCH] sched: add schedstat_set() API
add the schedstat_set() API, to allow the reduction of
CONFIG_SCHEDSTAT related #ifdefs. No code changed.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-08-02 17:41:40 +02:00
Balbir Singh
172ba844a8 sched: update delay-accounting to use CFS's precise stats
update delay-accounting to use CFS's precise stats.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 18:52:00 +02:00
Ingo Molnar
425e0968a2 sched: move code into kernel/sched_stats.h
create sched_stats.h and move sched.c schedstats code into it.
This cleans up sched.c a bit.

no code changes are caused by this patch.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-09 18:51:58 +02:00