lkml.org 
[lkml]   [2010]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: FW: sched_setaffinity not working with kernel 2.6.32.15
    On Sun, 20 Jun 2010 22:10:18 +0300
    ____________________ ______________________________ <psxlover@hotmail.com> wrote:

    >
    > From: psxlover@hotmail.com
    > To: mingo@elte.hu; peterz@infradead.org
    > Subject:
    > sched_setaffinity not working with kernel 2.6.32.15
    > Date: Sun, 20
    > Jun 2010 17:14:12 +0300

    I assume from this that you initially sent the email privately to
    Peter&Ingo, then forwarded it to the list without cc'ing Peter&Ingo.
    So if they're already responded to the inital email, I'm wasting my
    time. Ho hum.

    > ...

    That's a great bug report - fully bisected and it includes a testcase.
    Thanks.

    However I think your testcase is buggy. You have main() racing against
    print_affinity(). If a sub-thread runs print_affinity() before main()
    has run set_threadaffinity(), print_affinity() will obviously print
    main()'s affinity.

    Between 2.6.18 and 2.6.35-rc3 the timing changed a bit - in the later
    kernel the sub-threads are running before main() is able to change
    their affinity. In the earlier kernel the sub-threads run first.

    In both kernels, all CPU consumption is on CPU 0 as desired.

    Re-enabling the sleep(1) in threadCode() fixes the print_affinity()
    output, confirming that it's a userspace race.



    \
     
     \ /
      Last update: 2010-06-23 02:19    [W:0.028 / U:60.296 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site