Messages in this thread |  | | Date | Thu, 12 Dec 2013 11:34:58 -0500 | From | Sasha Levin <> | Subject | Re: [RFC][PATCH 3/5] timekeeping: Avoid possible deadlock from clock_was_set_delayed |
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On 12/11/2013 02:11 PM, John Stultz wrote: > As part of normal operaions, the hrtimer subsystem frequently calls > into the timekeeping code, creating a locking order of > hrtimer locks -> timekeeping locks > > clock_was_set_delayed() was suppoed to allow us to avoid deadlocks > between the timekeeping the hrtimer subsystem, so that we could > notify the hrtimer subsytem the time had changed while holding > the timekeeping locks. This was done by scheduling delayed work > that would run later once we were out of the timekeeing code. > > But unfortunately the lock chains are complex enoguh that in > scheduling delayed work, we end up eventually trying to grab > an hrtimer lock. > > Sasha Levin noticed this in testing when the new seqlock lockdep > enablement triggered the following (somewhat abrieviated) message:
[snip]
This seems to work for me, I don't see the lockdep spew anymore.
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Thanks, Sasha
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