Messages in this thread | | | Subject | Re: 3.4.4-rt13: btrfs + xfstests 006 = BOOM.. and a bonus rt_mutex deadlock report for absolutely free! | From | Mike Galbraith <> | Date | Mon, 16 Jul 2012 18:36:07 +0200 |
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On Mon, 2012-07-16 at 18:26 +0200, Mike Galbraith wrote: > On Mon, 2012-07-16 at 12:02 -0400, Steven Rostedt wrote: > > On Mon, 2012-07-16 at 04:02 +0200, Mike Galbraith wrote: > > > > > > Great, thanks! I got stuck in bug land on Friday. You mentioned > > > > performance problems earlier on Saturday, did this improve performance? > > > > > > Yeah, the read_trylock() seems to improve throughput. That's not > > > heavily tested, but it certainly looks like it does. No idea why. > > > > Ouch, you just turned the rt_read_lock() into a spin lock. If a higher > > priority process preempted a lower priority process that holds the same > > lock, it will deadlock. > > Hm, how, it's doing cpu_chill()?
'course PI is toast, so *poof*. Since just enabling the lockdep bits seems to fix it up, maybe that's the patchlet to submit (less is more).
-Mike
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