• Alexander Yarygin's avatar
    perf kvm stat live: Enable events copying · 673d659f
    Alexander Yarygin authored
    Process of analyzing events caused by 2 functions: mmap_read() and
    finished_round().
    
    During mmap_read(), perf receives events from shared memory, queues
    their pointers for further processing in finished_round() and notifies
    the kernel that the events have been processed.
    
    By the time when finished_round() is invoked, queued events can be
    overwritten by the kernel, so the finished_round() occurs on potentially
    corrupted memory.
    
    Since there is no place where the event can be safely consumed, let's
    copy events when queueing.
    Signed-off-by: default avatarAlexander Yarygin <yarygin@linux.vnet.ibm.com>
    Cc: Christian Borntraeger <borntraeger@de.ibm.com>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Namhyung Kim <namhyung.kim@lge.com>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Stephane Eranian <eranian@google.com>
    Link: http://lkml.kernel.org/r/1412347212-28237-3-git-send-email-yarygin@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    673d659f
builtin-kvm.c 35.1 KB