1. 21 Dec, 2010 1 commit
    • Ian Munsie's avatar
      perf session: Fallback to unordered processing if no sample_id_all · 21ef97f0
      Ian Munsie authored
      If we are running the new perf on an old kernel without support for
      sample_id_all, we should fall back to the old unordered processing of
      events. If we didn't than we would *always* process events without
      timestamps out of order, whether or not we hit a reordering race. In
      other words, instead of there being a chance of not attributing samples
      correctly, we would guarantee that samples would not be attributed.
      
      While processing all events without timestamps before events with
      timestamps may seem like an intuitive solution, it falls down as
      PERF_RECORD_EXIT events would also be processed before any samples.
      Even with a workaround for that case, samples before/after an exec would
      not be attributed correctly.
      
      This patch allows commands to indicate whether they need to fall back to
      unordered processing, so that commands that do not care about timestamps
      on every event will not be affected. If we do fallback, this will print
      out a warning if report -D was invoked.
      
      This patch adds the test in perf_session__new so that we only need to
      test once per session. Commands that do not use an event_ops (such as
      record and top) can simply pass NULL in it's place.
      Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      LKML-Reference: <1291951882-sup-6069@au1.ibm.com>
      Signed-off-by: default avatarIan Munsie <imunsie@au1.ibm.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      21ef97f0
  2. 16 Dec, 2010 9 commits
  3. 13 Dec, 2010 1 commit
  4. 09 Dec, 2010 15 commits
  5. 08 Dec, 2010 10 commits
  6. 07 Dec, 2010 4 commits