From: David Miller <davem@davemloft.net>
To: mingo@elte.hu
Cc: linux-kernel@vger.kernel.org
Subject: Soft lockup regression from today's sched.git merge.
Date: Tue, 22 Apr 2008 01:59:31 -0700 (PDT) [thread overview]
Message-ID: <20080422.015931.70144614.davem@davemloft.net> (raw)
The following commit:
commit 27ec4407790d075c325e1f4da0a19c56953cce23
Author: Ingo Molnar <mingo@elte.hu>
Date: Thu Feb 28 21:00:21 2008 +0100
sched: make cpu_clock() globally synchronous
Alexey Zaytsev reported (and bisected) that the introduction of
cpu_clock() in printk made the timestamps jump back and forth.
Make cpu_clock() more reliable while still keeping it fast when it's
called frequently.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
causes watchdog triggers when a cpu exits NOHZ state when it has been
there for >= the soft lockup threshold, for example here are some
messages from a 128 cpu Niagara2 box:
[ 168.106406] BUG: soft lockup - CPU#11 stuck for 128s! [dd:3239]
[ 168.989592] BUG: soft lockup - CPU#21 stuck for 86s! [swapper:0]
[ 168.999587] BUG: soft lockup - CPU#29 stuck for 91s! [make:4511]
[ 168.999615] BUG: soft lockup - CPU#2 stuck for 85s! [swapper:0]
[ 169.020514] BUG: soft lockup - CPU#37 stuck for 91s! [swapper:0]
[ 169.020514] BUG: soft lockup - CPU#45 stuck for 91s! [sh:4515]
[ 169.020515] BUG: soft lockup - CPU#69 stuck for 92s! [swapper:0]
[ 169.020515] BUG: soft lockup - CPU#77 stuck for 92s! [swapper:0]
[ 169.020515] BUG: soft lockup - CPU#61 stuck for 92s! [swapper:0]
[ 169.112554] BUG: soft lockup - CPU#85 stuck for 92s! [swapper:0]
[ 169.112554] BUG: soft lockup - CPU#101 stuck for 92s! [swapper:0]
[ 169.112554] BUG: soft lockup - CPU#109 stuck for 92s! [swapper:0]
[ 169.112554] BUG: soft lockup - CPU#117 stuck for 92s! [swapper:0]
[ 169.171483] BUG: soft lockup - CPU#40 stuck for 80s! [dd:3239]
[ 169.331483] BUG: soft lockup - CPU#13 stuck for 86s! [swapper:0]
[ 169.351500] BUG: soft lockup - CPU#43 stuck for 101s! [dd:3239]
[ 169.531482] BUG: soft lockup - CPU#9 stuck for 129s! [mkdir:4565]
[ 169.595754] BUG: soft lockup - CPU#20 stuck for 93s! [swapper:0]
[ 169.626787] BUG: soft lockup - CPU#52 stuck for 93s! [swapper:0]
[ 169.626787] BUG: soft lockup - CPU#84 stuck for 92s! [swapper:0]
[ 169.636812] BUG: soft lockup - CPU#116 stuck for 94s! [swapper:0]
It's simple enough to trigger this by doing a 10 minute sleep after a
fresh bootup then starting a parallel kernel build.
I suspect this might be reintroducing a problem we've had and fixed
before, see the thread:
http://marc.info/?l=linux-kernel&m=119546414004065&w=2
Please have a look, thank you.
next reply other threads:[~2008-04-22 8:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-22 8:59 David Miller [this message]
2008-04-22 9:14 ` Soft lockup regression from today's sched.git merge Ingo Molnar
2008-04-22 10:05 ` David Miller
2008-04-22 12:45 ` Peter Zijlstra
2008-05-06 22:41 ` Rafael J. Wysocki
2008-05-06 23:05 ` David Miller
2008-05-07 6:43 ` Ingo Molnar
2008-05-07 18:56 ` Rafael J. Wysocki
2008-04-23 8:50 ` [patch] softlockup: fix false positives on nohz if CPU is 100% idle for more than 60 seconds Ingo Molnar
2008-04-23 10:55 ` David Miller
2008-04-23 12:29 ` David Miller
2008-04-23 13:36 ` Ingo Molnar
2008-04-23 23:23 ` David Miller
2008-04-23 5:42 ` Soft lockup regression from today's sched.git merge David Miller
2008-04-23 7:32 ` Dhaval Giani
2008-04-23 7:51 ` Ingo Molnar
2008-04-23 9:40 ` Ingo Molnar
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