• Peter Zijlstra's avatar
    perf_counter: Simplify and fix task migration counting · e5289d4a
    Peter Zijlstra authored
    The task migrations counter was causing rare and hard to decypher
    memory corruptions under load. After a day of debugging and bisection
    we found that the problem was introduced with:
    
      3f731ca6: perf_counter: Fix cpu migration counter
    
    Turning them off fixes the crashes. Incidentally, the whole
    perf_counter_task_migration() logic can be done simpler as well,
    by injecting a proper sw-counter event.
    
    This cleanup also fixed the crashes. The precise failure mode is
    not completely clear yet, but we are clearly not unhappy about
    having a fix ;-)
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
    Cc: Marcelo Tosatti <mtosatti@redhat.com>
    Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
    LKML-Reference: <new-submission>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    e5289d4a
sched.c 258 KB