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kernel-ark/kernel/sched
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Stanislaw Gruszka 68aa8efcd1 sched: Avoid prev->stime underflow 
Dave Hansen reported strange utime/stime values on his system:
https://lkml.org/lkml/2013/4/4/435

This happens because prev->stime value is bigger than rtime
value. Root of the problem are non-monotonic rtime values (i.e.
current rtime is smaller than previous rtime) and that should be
debugged and fixed.

But since problem did not manifest itself before commit
62188451f0 "cputime: Avoid
multiplication overflow on utime scaling", it should be threated
as regression, which we can easily fixed on cputime_adjust()
function.

For now, let's apply this fix, but further work is needed to fix
root of the problem.

Reported-and-tested-by: Dave Hansen <dave@sr71.net>
Cc: <stable@vger.kernel.org> # 3.9+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: rostedt@goodmis.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1367314507-9728-3-git-send-email-sgruszka@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-04-30 19:13:05 +02:00
..
auto_group.c sched: split out css_online/css_offline from tg creation/destruction 2013-01-24 12:05:18 -08:00
auto_group.h Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" 2012-12-11 10:23:45 +01:00
clock.c
core.c sched: Rename load_balance_tmpmask to load_balance_mask 2013-04-24 08:52:45 +02:00
cpuacct.c sched/cpuacct/UML: Fix header file dependency bug on the UML build 2013-04-10 15:12:41 +02:00
cpuacct.h sched/cpuacct: Initialize root cpuacct earlier 2013-04-10 13:54:20 +02:00
cpupri.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
cpupri.h
cputime.c sched: Avoid prev->stime underflow 2013-04-30 19:13:05 +02:00
debug.c Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-26 19:42:08 -08:00
fair.c sched: Fix init NOHZ_IDLE flag 2013-04-26 12:13:44 +02:00
features.h Automatic NUMA Balancing V11 2012-12-16 15:18:08 -08:00
idle_task.c sched: Fix wrong rq's runnable_avg update with rt tasks 2013-04-21 11:22:52 +02:00
Makefile sched: Split cpuacct code out of core.c 2013-04-10 13:54:15 +02:00
rt.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
sched.h sched: Fix init NOHZ_IDLE flag 2013-04-26 12:13:44 +02:00
stats.c sched: Fix /proc/sched_stat failure on very very large systems 2013-02-22 10:27:24 +01:00
stats.h
stop_task.c