• Peter Zijlstra's avatar
    perf_events: Fix sample_period transfer on inherit · 75c9f328
    Peter Zijlstra authored
    One problem with frequency driven counters is that we cannot
    predict the rate at which they trigger, therefore we have to
    start them at period=1, this causes a ramp up effect. However,
    if we fail to propagate the stable state on fork each new child
    will have to ramp up again. This can lead to significant
    artifacts in sample data.
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: eranian@google.com
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    LKML-Reference: <1264752266.4283.2121.camel@laptop>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    75c9f328
perf_event.c 126 KB