Messages in this thread | | | Date | Mon, 20 Mar 2023 10:14:51 +0530 | Subject | Re: NMI reason 2d when running perf | From | Ravi Bangoria <> |
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On 17-Mar-23 7:55 PM, Jens Axboe wrote: > Hi, > > When running perf on my Dell R7525 on a running process, I get a ton of: > > [ 504.234782] Dazed and confused, but trying to continue > [ 504.267843] Uhhuh. NMI received for unknown reason 2d on CPU 48. > [ 504.267846] Dazed and confused, but trying to continue > [ 504.335975] Uhhuh. NMI received for unknown reason 2d on CPU 48. > [ 504.335977] Dazed and confused, but trying to continue > [ 504.368031] Uhhuh. NMI received for unknown reason 2d on CPU 48. > [ 504.368033] Dazed and confused, but trying to continue > [ 504.371037] Uhhuh. NMI received for unknown reason 2d on CPU 48. > [ 504.371038] Dazed and confused, but trying to continue > [ 504.439165] Uhhuh. NMI received for unknown reason 2d on CPU 48. > [ 504.439167] Dazed and confused, but trying to continue > > spew in dmesg. The box has 2x7763 CPUS.
Are you using IBS directly or indirectly (perf record, if run as root without explicit -e event, internally invokes IBS)? fwiw, Zen2 had similar hw issue where IBS can raise NMI without sample valid bit set while exiting from CC6 state[1]. But as per my knowledge, it's already fixed in Zen3.
[1]: https://lore.kernel.org/all/YFDSSxftYw9tCGC6@krava/
> This seems to be a recent > regression, been using this box for a while and haven't seen this > before. The test being traced is pinned to CPU 48. The box is currently > running: > > commit 6015b1aca1a233379625385feb01dd014aca60b5 (origin/master, origin/HEAD) > Author: Linus Torvalds <torvalds@linux-foundation.org> > Date: Tue Mar 14 19:32:38 2023 -0700 > > sched_getaffinity: don't assume 'cpumask_size()' is fully initialized > > with the pending block/io_uring branches merged in for testing. >
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