Messages in this thread | | | Date | Tue, 11 Sep 2007 09:58:32 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: 2.6.23-rc6: hanging ext3 dbench tests |
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On Tue, 11 Sep 2007, Andy Whitcroft wrote: > > I have a couple of failed test runs against 2.6.23-rc6 where the > job timed out while running dbench over ext3. Both on powerpc, > though both significantly different hardware setups. A failed > run like this implies that the machine was still responsive to > other processes but the dbench was making no progress. There is > no console diagnostics during the failure.
Since the machine seems to be otherwise alive, can you do a sysrq-W (which is most easily done by just doing a
echo w > /proc/sysrq-trigger
and you don't actually need any console access or anything like that).
That should give you all the blocked process traces, and if it's a deadlock on some semaphore or other, it should all stand out quite nicely.
In fact, things like the above are probably worth scripting for any automated testing - if you auto-fail after some time, please make the failure case do that sysrq-W by default.
(The other sysrq things can be useful too - "T" shows the same as "W", except for _all_ tasks, which is often so verbose that it hides the problem, but is sometimes the right thing to do).
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