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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-05-31 18:13:25 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-06-01 09:27:17 +0200 |
| commit | 02f726949f2be0967aa4871dd4e47d3967779b26 (patch) | |
| tree | cca72d10f5db4d5d2b37c0d3fb9c424fbef051ca /include | |
| parent | e51fd5e22e12b39f49b1bb60b37b300b17378a43 (diff) | |
| download | linux-02f726949f2be0967aa4871dd4e47d3967779b26.tar.bz2 | |
sched, trace: Fix sched_switch() prev_state argument
For CONFIG_PREEMPT=y kernels the sched_switch(.prev_state) argument isn't
useful because we can get preempted with current->state != TASK_RUNNING
without actually getting removed from the runqueue.
Cure this by treating all preempted tasks as runnable from the tracer's
point of view.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cautiously-acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1275322715.27810.23323.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
| -rw-r--r-- | include/trace/events/sched.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 4f733ecea46e..b9e1dd6c6208 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -115,6 +115,23 @@ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, TP_PROTO(struct task_struct *p, int success), TP_ARGS(p, success)); +#ifdef CREATE_TRACE_POINTS +static inline long __trace_sched_switch_state(struct task_struct *p) +{ + long state = p->state; + +#ifdef CONFIG_PREEMPT + /* + * For all intents and purposes a preempted task is a running task. + */ + if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE) + state = TASK_RUNNING; +#endif + + return state; +} +#endif + /* * Tracepoint for task switches, performed by the scheduler: */ @@ -139,7 +156,7 @@ TRACE_EVENT(sched_switch, memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); __entry->prev_pid = prev->pid; __entry->prev_prio = prev->prio; - __entry->prev_state = prev->state; + __entry->prev_state = __trace_sched_switch_state(prev); memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); __entry->next_pid = next->pid; __entry->next_prio = next->prio; |