NMI Dazed and Confused messages

Severity

Minor, mostly just syslog spam

Found With

perf_fuzzer

Reproducible

Yes

Summary

Included with the perf_event tests suite is a small chunk of code found by the tester that will flood the syslog of a core2 machine with NMI messages.

First Reported

3.12

Most recently seen

4.9-rc0

Seen On

Core2 (mostly). Also on Haswell and Pentium 4.

Reported to lkml

14 November 2013 -- perf/nmi : NMI Dazed and confused messages on core2

Kernel Spew

  1. *** perf_fuzzer 0.28 *** by Vince Weaver

        Linux version 3.15.0-rc1+ x86_64
        Processor: Intel 6/60/3

        Seeding random number generator with 1399334266
        /proc/sys/kernel/perf_event_max_sample_rate currently: 12500/s
        /proc/sys/kernel/perf_event_paranoid currently: 1
        Logging perf_event_open() failures: no
        Running fsync after every syscall: no
        To reproduce, try: ./perf_fuzzer -t OCIRMQWPFpAi -s 50000 -r 1399334266

Pid=28172, sleeping 1s
==================================================
Fuzzing the following syscalls:
        mmap perf_event_open close read write ioctl fork prctl poll 
*NOT* Fuzzing the following syscalls:
        
Also attempting the following:
        busy-instruction-loop accessing-perf-proc-and-sys-files trashing-the-mmap-page 
*NOT* attempting the following:
        signal-handler-on-overflow 
==================================================
Iteration 10000
        Open attempts: 351457  Successful: 947
                EPERM : 9
                ENOENT : 973
                E2BIG : 40892
                EBADF : 5819
                EACCES : 263
                EINVAL : 301703
                ENOSPC : 153
                EOPNOTSUPP : 698
        Close attempts: 928  Successful: 928
        Read attempts: 908  Successful: 761
        Write attempts: 898  Successful: 0
        Ioctl attempts: 836  Successful: 394
        Mmap attempts: 947  Successful: 278
        Prctl attempts: 865  Successful: 865
        Fork attempts: 440  Successful: 440
        Poll attempts: 939  Successful: 22
        Access attempts: 887  Successful: 439
        Trash mmap attempts: 923  Successful: 923
        Overflows: 0
        SIGIOs due to RT signal queue full: 0
Iteration 20000
        Open attempts: 353865  Successful: 933
                EPERM : 17
                ENOENT : 906
                E2BIG : 40757
                EBADF : 5737
                EACCES : 260
                EINVAL : 304248
                ENOSPC : 275
                EOPNOTSUPP : 732
        Close attempts: 878  Successful: 878
        Read attempts: 913  Successful: 794
        Write attempts: 911  Successful: 0
        Ioctl attempts: 889  Successful: 400
        Mmap attempts: 933  Successful: 256
        Prctl attempts: 905  Successful: 905
        Fork attempts: 472  Successful: 472
        Poll attempts: 896  Successful: 97
        Access attempts: 940  Successful: 473
        Trash mmap attempts: 876  Successful: 876
        Overflows: 0
        SIGIOs due to RT signal queue full: 0
Iteration 30000
        Open attempts: 346492  Successful: 914
                EPERM : 24
                ENOENT : 947
                E2BIG : 40433
                EBADF : 5478
                EACCES : 240
                EINVAL : 297368
                ENOSPC : 367
                EOPNOTSUPP : 721
        Close attempts: 885  Successful: 885
        Read attempts: 940  Successful: 797
        Write attempts: 861  Successful: 0
        Ioctl attempts: 944  Successful: 436
        Mmap attempts: 914  Successful: 229
        Prctl attempts: 900  Successful: 900
        Fork attempts: 438  Successful: 438
        Poll attempts: 908  Successful: 8
        Access attempts: 897  Successful: 448
        Trash mmap attempts: 925  Successful: 925
        Overflows: 0
        SIGIOs due to RT signal queue full: 0
[32503.108958] Uhhuh. NMI received for unknown reason 31 on CPU 3.
[32503.115306] Do you have a strange power saving mode enabled?
[32503.121384] Dazed and confused, but trying to continue

  2. [ 7911.810186] Uhhuh. NMI received for unknown reason 3d on CPU 0.
[ 7911.812756] Do you have a strange power saving mode enabled?
[ 7911.812756] Dazed and confused, but trying to continue
[ 7912.554225] Uhhuh. NMI received for unknown reason 2d on CPU 1.
[ 7912.556758] Do you have a strange power saving mode enabled?
[ 7912.556758] Dazed and confused, but trying to continue
[ 7912.838169] Uhhuh. NMI received for unknown reason 2d on CPU 0.
[ 7912.840726] Do you have a strange power saving mode enabled?
[ 7912.840726] Dazed and confused, but trying to continue
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