Re: NMI reason 2d when running perf

From: Dr. David Alan Gilbert
Date: Sat Mar 18 2023 - 11:59:01 EST


* Jens Axboe (axboe@xxxxxxxxx) 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. 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:

I'm not sure this is new; I've seen this intermittently on AMD boxes
for a few years. Always when running perf or related tools.

Dave

> commit 6015b1aca1a233379625385feb01dd014aca60b5 (origin/master, origin/HEAD)
> Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> 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.
>
> --
> Jens Axboe
>
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