From: Stanislaw Gruszka <sgruszka@redhat.com>
To: Dave Hansen <dave@sr71.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Subject: Re: sched/cputime: sig->prev_stime underflow
Date: Fri, 3 May 2013 13:00:04 +0200 [thread overview]
Message-ID: <20130503110003.GA1588@redhat.com> (raw)
In-Reply-To: <51828EC8.5090805@sr71.net>
On Thu, May 02, 2013 at 09:05:28AM -0700, Dave Hansen wrote:
> On 04/30/2013 05:36 AM, Stanislaw Gruszka wrote:
> > On Tue, Apr 16, 2013 at 02:05:22PM -0700, Dave Hansen wrote:
> >>> But since this (most likely) is rtime monotonicity problem it
> >>> is bug by itself and probably that should be fixed. Can you
> >>> check second patch attached and see if it trigger the warning.
> >>
> >> Yup, it triggers lots of warnings. Here's one.
> >>
> >>> [ 460.789710] ------------[ cut here ]------------
> >>> [ 460.789730] WARNING: at /home/davehans/linux.git/kernel/sched/cputime.c:563 cputime_adjust+0xe6/0xf0()
> >>> [ 460.789736] Hardware name: PRIMEQUEST 1800E2
> >>> [ 460.789739] Modules linked in:
> >>> [ 460.789745] Pid: 4245, comm: top Tainted: G W 3.9.0-rc7-00004-gbb33db7-dirty #19
> >>> [ 460.789748] Call Trace:
> >>> [ 460.789777] [<ffffffff810c6dc7>] warn_slowpath_common+0xb7/0x120
> >>> [ 460.789783] [<ffffffff810c6e5a>] warn_slowpath_null+0x2a/0x40
> >>> [ 460.789789] [<ffffffff8111a8d6>] cputime_adjust+0xe6/0xf0
> >>> [ 460.789795] [<ffffffff8111b755>] ? thread_group_cputime+0x5/0x140
> >>> [ 460.789800] [<ffffffff8111bbb9>] thread_group_cputime_adjusted+0x59/0x70
> >
> > Dave, could you test attached patch and check if make warnings gone.
> > Patch is not right fix, but if it prevent the warnings, this will
> > give clue where the problem can be.
>
> Does this have any relation to the other four -tip patches you also
> posted? What do you want this applied on top of?
No, they are not related. But if you apply patch " sched: Avoid
prev->stime underflow", you will also need previous additional
patch, which WARN if rtime goes backward to detect that condition
and see if it is fixed by times->sum_exec_runtime calculation
change.
Stanislaw
prev parent reply other threads:[~2013-05-03 10:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-04 17:40 sched/cputime: sig->prev_stime underflow Dave Hansen
2013-04-04 23:41 ` Frederic Weisbecker
2013-04-08 15:57 ` Dave Hansen
2013-04-11 7:45 ` Stanislaw Gruszka
2013-04-11 18:47 ` Dave Hansen
2013-04-16 11:06 ` Stanislaw Gruszka
2013-04-16 21:05 ` Dave Hansen
2013-04-30 12:36 ` Stanislaw Gruszka
2013-05-02 16:05 ` Dave Hansen
2013-05-03 11:00 ` Stanislaw Gruszka [this message]
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