diff options
| author |   Steven Rostedt <rostedt@goodmis.org> | 2008-07-10 20:58:09 -0400 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2008-07-11 15:49:18 +0200 |
| commit | 007c05d4d2ce42fabd58cb54ed98e0a1714d9d86 (patch) | |
| tree | 94873072975275a1e03ccc1dad27a15c41ee3cc4 /kernel/trace/trace.h | |
| parent | ftrace: prevent ftrace modifications while being kprobe'd, v2 (diff) | |
| download | linux-dev-007c05d4d2ce42fabd58cb54ed98e0a1714d9d86.tar.xz linux-dev-007c05d4d2ce42fabd58cb54ed98e0a1714d9d86.zip | |
ftrace: move sched_switch enable after markers
We have two markers now that are enabled on sched_switch. One that records
the context switching and the other that records task wake ups. Currently
we enable the tracing first and then set the markers. This causes some
confusing traces:
# tracer: sched_switch
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
trace-cmd-3973 [00] 115.834817: 3973:120:R + 3: 0:S
trace-cmd-3973 [01] 115.834910: 3973:120:R + 6: 0:S
trace-cmd-3973 [02] 115.834910: 3973:120:R + 9: 0:S
trace-cmd-3973 [03] 115.834910: 3973:120:R + 12: 0:S
trace-cmd-3973 [02] 115.834910: 3973:120:R + 9: 0:S
<idle>-0 [02] 115.834910: 0:140:R ==> 3973:120:R
Here we see that trace-cmd with PID 3973 wakes up task 9 but the next line
shows the idle task doing a context switch to task 3973.
Enabling the tracing to _after_ the markers are set creates a much saner
output:
# tracer: sched_switch
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
<idle>-0 [02] 7922.634225: 0:140:R ==> 4790:120:R
trace-cmd-4789 [03] 7922.634225: 0:140:R + 4790:120:R
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace.h')
0 files changed, 0 insertions, 0 deletions