• Maria Dimakopoulou's avatar
    perf/x86: Fix constraint table end marker bug · cf30d52e
    Maria Dimakopoulou authored
    The EVENT_CONSTRAINT_END() macro defines the end marker as
    a constraint with a weight of zero. This was all fine
    until we blacklisted the corrupting memory events on
    Intel IvyBridge. These events are blacklisted by using
    a counter bitmask of zero. Thus, they also get a constraint
    weight of zero.
    
    The iteration macro: for_each_constraint tests the weight==0.
    Therefore, it was stopping at the first blacklisted event, i.e.,
    0xd0. The corrupting events were therefore considered as
    unconstrained and were scheduled on any of the generic counters.
    
    This patch fixes the end marker to have a weight of -1. With
    this, the blacklisted events get an empty constraint and cannot
    be scheduled which is what we want for now.
    Signed-off-by: default avatarMaria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
    Reviewed-by: default avatarStephane Eranian <eranian@google.com>
    Cc: peterz@infradead.org
    Cc: ak@linux.intel.com
    Cc: jolsa@redhat.com
    Cc: zheng.z.yan@intel.com
    Link: http://lkml.kernel.org/r/20131204232437.GA10689@starlightSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    cf30d52e
perf_event.h 18.4 KB