Message-ID: <25fccb43-8338-a690-0009-384dc0640169@kernel.dk>
Date:   Fri, 17 Mar 2023 08:25:47 -0600
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To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>, acme@kernel.org
Cc:     linux-perf-users@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
From:   Jens Axboe <axboe@kernel.dk>
Subject: NMI reason 2d when running perf
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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:

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.

-- 
Jens Axboe