Messages in this thread | | | Date | Mon, 19 May 2014 09:11:15 -0400 (EDT) | From | Vince Weaver <> | Subject | Re: perfevents: irq loop stuck! |
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On Fri, 16 May 2014, Peter Zijlstra wrote:
> On Fri, May 16, 2014 at 12:25:28AM -0400, Vince Weaver wrote: > > anyway I'm not sure if it's worth tracking this more if it's possible to > > mostly fix the case by fixing the sample_period bounds. > > Right, so lets start with that, if it triggers again, we'll have another > look.
I applied the patch and can verify it avoids the too-big-period-wrapping problem.
I left things fuzzing over the weekend, and eventually the bug triggered again. The problem issue still seems to be caused by "sample_period=2,fixed counter 0" so maybe there's an erratum out there I should be looking up.
The fuzzing also turned up a few other issues, and in the end after 2 days it locked up the machine so hard that it also took out the ethernet switch due to some sort of packet trasmit storm, which is a failure mode I have to admit I haven't encountered before.
Vince
[69213.252805] ------------[ cut here ]------------ [69213.260637] WARNING: CPU: 4 PID: 11343 at arch/x86/kernel/cpu/perf_event_intel.c:1373 intel_pmu_handle_irq+0x2a4/0x3c0() [69213.276788] perfevents: irq loop stuck! ... [69213.686561] CPU#4: ctrl: 0000000000000000 [69213.694352] CPU#4: status: 0000000000000000 [69213.701979] CPU#4: overflow: 0000000000000000 [69213.709599] CPU#4: fixed: 00000000000000b8 [69213.717172] CPU#4: pebs: 0000000000000000 [69213.724596] CPU#4: active: 0000000300000000 [69213.731939] CPU#4: gen-PMC0 ctrl: 000000000013412e [69213.739877] CPU#4: gen-PMC0 count: 000000000000002c [69213.747820] CPU#4: gen-PMC0 left: 0000ffffffffffd7 [69213.755657] CPU#4: gen-PMC1 ctrl: 0000000000138b40 [69213.763461] CPU#4: gen-PMC1 count: 00000000000086b3 [69213.771152] CPU#4: gen-PMC1 left: 0000ffffffff81c9 [69213.778742] CPU#4: gen-PMC2 ctrl: 000000000013024e [69213.786271] CPU#4: gen-PMC2 count: 0000000000000001 [69213.793784] CPU#4: gen-PMC2 left: 0000ffffffffffff [69213.801227] CPU#4: gen-PMC3 ctrl: 0000000000134f2e [69213.808720] CPU#4: gen-PMC3 count: 00000000000009f9 [69213.816192] CPU#4: gen-PMC3 left: 0000fffffffff6de [69213.823620] CPU#4: fixed-PMC0 count: 0000fffffffffffe [69213.831035] CPU#4: fixed-PMC1 count: 0000ffffea2a90b2 [69213.838477] CPU#4: fixed-PMC2 count: 00000000051c5865 [69213.845792] perf_event_intel: clearing PMU state on CPU#4
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