• D
    tracing: Format non-nanosec times from tsc clock without a decimal point. · 8be0709f
    David Sharp 提交于
    With the addition of the "tsc" clock, formatting timestamps to look like
    fractional seconds is misleading. Mark clocks as either in nanoseconds or
    not, and format non-nanosecond timestamps as decimal integers.
    
    Tested:
    $ cd /sys/kernel/debug/tracing/
    $ cat trace_clock
    [local] global tsc
    $ echo sched_switch > set_event
    $ echo 1 > tracing_on ; sleep 0.0005 ; echo 0 > tracing_on
    $ cat trace
              <idle>-0     [000]  6330.555552: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=29964 next_prio=120
               sleep-29964 [000]  6330.555628: sched_switch: prev_comm=bash prev_pid=29964 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
      ...
    $ echo 1 > options/latency-format
    $ cat trace
      <idle>-0       0 4104553247us+: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=29964 next_prio=120
       sleep-29964   0 4104553322us+: sched_switch: prev_comm=bash prev_pid=29964 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
      ...
    $ echo tsc > trace_clock
    $ cat trace
    $ echo 1 > tracing_on ; sleep 0.0005 ; echo 0 > tracing_on
    $ echo 0 > options/latency-format
    $ cat trace
              <idle>-0     [000] 16490053398357: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=31128 next_prio=120
               sleep-31128 [000] 16490053588518: sched_switch: prev_comm=bash prev_pid=31128 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
      ...
    echo 1 > options/latency-format
    $ cat trace
      <idle>-0       0 91557653238+: sched_switch: prev_comm=swapper prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=bash next_pid=31128 next_prio=120
       sleep-31128   0 91557843399+: sched_switch: prev_comm=bash prev_pid=31128 prev_prio=120 prev_state=S ==> next_comm=swapper next_pid=0 next_prio=120
      ...
    
    v2:
    Move arch-specific bits out of generic code.
    v4:
    Fix x86_32 build due to 64-bit division.
    
    Google-Bug-Id: 6980623
    Link: http://lkml.kernel.org/r/1352837903-32191-2-git-send-email-dhsharp@google.com
    
    Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
    Signed-off-by: NDavid Sharp <dhsharp@google.com>
    Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
    8be0709f
ftrace_event.h 9.0 KB