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IV56264: WHEN MULTITHREADED, GPROF SHOWS WRONG NUMBER OF FUNCTION CALLS APPLIES TO AIX 7100-03

A fix is available

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APAR status

  • Closed as program error.

Error description

  • In multithreaded environments, the gprof command displays
    smaller number of function calls than the actual number.
    In this example the right number of function calls
    are 256, however we get numbers like 254 or 255, running
    in a loop.
    
        $ ./xlf.out; gprof | grep sub2
        [1]      0.0    0.00        0.00     256
    .sub2 [1]     <== OK
                        0.00        0.00     256/256
    .sub2 [1]
          0.0       0.00     0.00      256     0.00     0.00
    .sub2 [1]
          [86] ._lib_mutex_unlock   [92] .monitor
     [1] .sub2
        $  ./xlf.out; gprof | grep sub2
        [1]      0.0    0.00        0.00     254
    .sub2 [1]    <== BAD
                        0.00        0.00     254/254
    .sub2 [1]
          0.0       0.00     0.00      254     0.00     0.00
    .sub2 [1]
          [86] ._lib_mutex_unlock   [92] .monitor
     [1] .sub2
    

Local fix

Problem summary

  • When using gprof to analyze the gmon.out file generated by a
    multi threaded process, the gprof might show incorrect number
    of function calls.
    

Problem conclusion

  • Ensure counter increments/decrements are thread-safe.
    

Temporary fix

Comments

  • 6100-07 - use AIX APAR IV58355
    6100-08 - use AIX APAR IV57965
    6100-09 - use AIX APAR IV56212
    6100-09 - use AIX APAR IV56212
    6100-09 - use AIX APAR IV56212
    7100-01 - use AIX APAR IV57635
    7100-02 - use AIX APAR IV51877
    7100-03 - use AIX APAR IV56264
    7100-04 - use AIX APAR IV56276
    

APAR Information

  • APAR number

    IV56264

  • Reported component name

    AIX V7.1

  • Reported component ID

    5765H4000

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2014-03-05

  • Closed date

    2014-03-05

  • Last modified date

    2016-05-10

  • APAR is sysrouted FROM one or more of the following:

    IV51877

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    AIX V7.1

  • Fixed component ID

    5765H4000

Applicable component levels

  • R710 PSY U858977

       UP14/05/22 I 1000

PTF to Fileset Mapping



Document information

More support for: AIX Enterprise Edition

Software version: 710

Operating system(s): AIX

Reference #: IV56264

Modified date: 10 May 2016