Messages in this thread | | | Date | Sat, 24 Oct 2015 00:12:36 +0200 | From | Peter Zijlstra <> | Subject | Re: perf: fuzzer triggered trouble on AMD, maybe ibs related |
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On Thu, Oct 22, 2015 at 12:46:53PM -0400, Vince Weaver wrote: > Hello > > I've been busy but finally had a chance to run perf_fuzzer on current git. > I am running on an AMD A10 system (my traditional Haswell system is > otherwise occupied). > > I got the following WARNING which was followed by an NMI storm which > eventually managed to confuse ext4 enough that my / partition was > remounted read-only? Very alarming. > > This is in static void perf_ibs_start(struct perf_event *event, int flags) > > if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED))) > return;
Hurm, its been a long while since I looked at the AMD IBS stuff. But looking at it I would not be surprised if there's weird interaction between the HES flags and IBS_flags.
But I'll have to look more careful..
> [ 468.763231] Dazed and confused, but trying to continue > [ 468.794184] Uhhuh. NMI received for unknown reason 2d on CPU 2. > [ 468.794184] Do you have a strange power saving mode enabled? > [ 468.794184] Dazed and confused, but trying to continue > [ 473.190535] sd 0:0:0:0: [sda] tag#2 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT > [ 473.199631] sd 0:0:0:0: [sda] tag#2 CDB: Write(10) 2a 00 39 93 49 d0 00 00 18 00
This might just be the NMI storm starving a device interrupt.
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