Re: perf: 3.17 another perf_fuzzer lockup

From: Vince Weaver
Date: Mon Oct 20 2014 - 00:42:11 EST


On Fri, 17 Oct 2014, Vince Weaver wrote:

> On Fri, 17 Oct 2014, Vince Weaver wrote:
>
> > Now to find out why this could happen. Probably something to do with
> > crazy RCU magic :(
>
> it looks like there's an unbalanced get_ctx() / put_ctx() here, as the
> software event context on the main process should not get decremented
> to 0 unless that process is exiting, yet it happens.
>
> Maybe this is bisectable. Hmmm.

nope. Wasted 3 days trying to bisect this. Something during the 3.17
merge window changed enough to make the perf_fuzzer results
non-deterministic, and that makes it nearly impossibe to reproduce the
issue properly. Ugh. I might be reduced to sprinkling printks around
unless anyone chimes in with better advice.

Vince
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