Zhaolei
b11c53e12f
ftrace: Add task_comm support for trace_event
If we enable a trace event alone without any tracer running (such as
function tracer, sched switch tracer, etc...) it can't output enough
task command information.
We need to use the tracing_{start/stop}_cmdline_record() helpers
which are designed to keep track of cmdlines for any tasks that
were scheduled during the tracing.
Before this patch:
# echo 1 > debugfs/tracing/events/sched/sched_switch/enable
# cat debugfs/tracing/trace
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
<...>-2289 [000] 526276.724790: sched_switch: task bash:2289 [120] ==> sshd:2287 [120]
<...>-2287 [000] 526276.725231: sched_switch: task sshd:2287 [120] ==> bash:2289 [120]
<...>-2289 [000] 526276.725452: sched_switch: task bash:2289 [120] ==> sshd:2287 [120]
<...>-2287 [000] 526276.727181: sched_switch: task sshd:2287 [120] ==> swapper:0 [140]
<idle>-0 [000] 526277.032734: sched_switch: task swapper:0 [140] ==> events/0:5 [115]
<...>-5 [000] 526277.032782: sched_switch: task events/0:5 [115] ==> swapper:0 [140]
...
After this patch:
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
bash-2269 [000] 527347.989229: sched_switch: task bash:2269 [120] ==> sshd:2267 [120]
sshd-2267 [000] 527347.990960: sched_switch: task sshd:2267 [120] ==> bash:2269 [120]
bash-2269 [000] 527347.991143: sched_switch: task bash:2269 [120] ==> sshd:2267 [120]
sshd-2267 [000] 527347.992959: sched_switch: task sshd:2267 [120] ==> swapper:0 [140]
<idle>-0 [000] 527348.531989: sched_switch: task swapper:0 [140] ==> events/0:5 [115]
events/0-5 [000] 527348.532115: sched_switch: task events/0:5 [115] ==> swapper:0 [140]
...
Changelog:
v1->v2: Update Kconfig to select CONTEXT_SWITCH_TRACER in
ENABLE_EVENT_TRACING
v2->v3: v2 can solve problem that was caused by config EVENT_TRACING
alone, but when CONFIG_FTRACE is off and CONFIG_TRACING is
selected by other config, compile fail happened again.
This version solves it.
[ Impact: fix incomplete output of event tracing ]
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A14FDFE.2080402@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-05-26 03:03:21 +02:00
..
2009-05-19 10:29:21 +02:00
2009-05-18 10:24:13 +02:00
2009-05-26 03:03:21 +02:00
2009-04-14 00:00:56 +02:00
2009-05-07 13:36:22 +02:00
2009-05-11 13:22:26 -04:00
2009-05-11 23:33:06 -04:00
2009-04-07 14:43:06 +02:00
2009-05-07 11:17:34 +02:00
2009-03-22 18:16:54 +01:00
2009-05-06 10:38:19 +02:00
2009-04-29 14:06:03 +02:00
2009-05-14 23:55:12 -04:00
2009-05-26 03:03:21 +02:00
2009-04-29 14:06:03 +02:00
2009-03-24 23:41:11 -04:00
2009-02-18 01:40:20 +01:00
2009-05-07 13:36:22 +02:00
2009-03-04 22:15:30 -05:00
2009-04-07 14:43:06 +02:00
2009-03-23 09:22:15 +01:00
2009-05-25 23:53:41 +02:00
2009-05-25 23:53:41 +02:00
2009-05-07 11:17:34 +02:00
2009-04-07 14:43:07 +02:00
2009-04-14 22:05:43 -04:00
2009-04-23 23:01:36 -04:00
2008-05-23 21:13:23 +02:00
2009-04-07 13:36:21 +02:00
2009-04-07 14:43:07 +02:00
2009-04-07 13:47:45 +02:00
2009-03-24 23:22:58 -04:00
2009-04-09 05:43:32 +02:00
2009-04-07 14:43:07 +02:00
2009-04-07 13:47:45 +02:00
2009-05-25 23:53:41 +02:00
2009-05-07 13:36:22 +02:00