• Stephane Eranian's avatar
    perf: Disable PERF_RECORD_MMAP2 support · 3090ffb5
    Stephane Eranian authored
    For now, we disable the extended MMAP record support (MMAP2).
    
    We have identified cases where it would not report the correct mapping
    information, clone(VM_CLONE) but with separate pids.  We will revisit
    the support once we find a solution for this case.
    
    The patch changes the kernel to return EINVAL if attr->mmap2 is set. The
    patch also modifies the perf tool to use regular PERF_RECORD_MMAP for
    synthetic events and it also prevents the tool from requesting
    attr->mmap2 mode because the kernel would reject it.
    
    The support will be revisited once the kenrel interface is updated.
    
    In V2, we reduce the patch to the strict minimum.
    
    In V3, we avoid calling perf_event_open() with mmap2 set because we know
    it will fail and require fallback retry.
    Signed-off-by: default avatarStephane Eranian <eranian@google.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Link: http://lkml.kernel.org/r/20131017173215.GA8820@quadSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    3090ffb5
event.c 19.7 KB