Messages in this thread | | | Subject | Re: [2.6.33-rc5] Weird deadlock when shutting down | From | Johannes Berg <> | Date | Thu, 18 Feb 2010 19:45:35 +0100 |
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On Thu, 2010-02-18 at 08:31 -0800, Linus Torvalds wrote:
> > > halt/4071 is trying to acquire lock: > > > (s_active){++++.+}, at: [<c0000000001ef868>] > > > .sysfs_addrm_finish+0x58/0xc0 > > > > > > but task is already holding lock: > > > (&per_cpu(cpu_policy_rwsem, cpu)){+.+.+.}, at: > [<c0000000004cd6ac>] > > > .lock_policy_rwsem_write+0x84/0xf4 > > > > > > which lock already depends on the new lock. > > You don't have a full backtrace for these things?
No, it deadlocks right there, unfortunately.
> We've had lots of trouble with the cpu governors, and I suspect the > problem isn't new, but the lockdep warning is likely new (see commit > 846f99749ab68bbc7f75c74fec305de675b1a1bf: "sysfs: Add lockdep > annotations > for the sysfs active reference"). > > So it is likely to be an old issue that (a) now gets warned about and > (b) might have had timing changes enough to trigger it.
Well, it used to not deadlock and actually shut down the machine :) So in that sense it's definitely new. It might have printed a lockdep warning before, which you wouldn't normally see since the machine turns off right after this.
> I suspect it is G5-specific (or specific to whatever CPU frequency > code > that gets used there), since I think we'd have had lots of reports if > this > happened on x86.
Yeah, that's puzzling me as well.
johannes [unhandled content-type:application/pgp-signature] | |