[lkml]   [2010]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    Subject[PATCH 0/4] [GIT PULL] tracing: Harry Potter and the Deathly Macros


    This pull request is for 2.6.38.

    The first two patches are boring and are just some updates for tracing.

    But the second two patches are the Deathly Macros.

    The first of the two is the Macro of Invisibility. Not really anything
    to worry about. It adds the TP_CONDITION() which allows a tracepoint
    to "hide" unwanted traces nicely. If the condition is not met, that
    tracepoint will not be traced. Also, the "if" statement is outside
    the fast path and is only hit during actual tracing (not there when
    tracing is disabled).

    The second patch is the Macro of Resurrection. It is resurrecting
    the debate about stable tracepoints and if current tracepoints may change.
    This patch uses the first patch to only trace the wakeup tracepoint
    if it succeeds to actually wake something up. This makes the
    "success" field in the tracepoint redundant and it seems silly to
    keep it there. It wastes space in the buffers and adds a slight overhead
    just to record it. But this wasted space is more of an issue than
    the overhead.

    Now if we change this, it may break tools that analyze the wakeup
    tracepoint and checks the "success" field to know if it should
    ignore it or not. Any tools that do this should have tested to
    see if that field was there and if not assume the wakeup succeeded.

    If we had the Macro of Invinicibility (true stable events), then
    this would not be an issue for us. But unfortunately, the Macro of
    Invincibility is not here, and is probably buried somewhere
    with an old gay wizard.

    Please pull the latest tip/perf/core tree, which can be found at:


    Steven Rostedt (3):
    tracing/events: Show real number in array fields
    tracing: Only trace sched_wakeup if it actually work something up

    Wu Zhangjin (1):
    ftrace: Speed up recordmcount

    include/linux/ftrace_event.h | 4 ++++
    include/linux/tracepoint.h | 29 +++++++++++++++++++++++------
    include/trace/define_trace.h | 15 +++++++++++++++
    include/trace/events/sched.h | 16 ++++++++--------
    include/trace/ftrace.h | 14 ++++++++++----
    kernel/trace/trace_events.c | 6 ++++++
    kernel/trace/trace_export.c | 14 ++++++++++----
    scripts/ | 13 +++++++++----
    8 files changed, 85 insertions(+), 26 deletions(-)

     \ /
      Last update: 2010-12-04 03:33    [W:0.031 / U:89.880 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site