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| author |   Pavankumar Kondeti <pkondeti@codeaurora.org> | 2018-10-30 12:24:33 +0530 |
|---|---|---|
| committer |   Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-11-27 20:31:55 -0500 |
| commit | 3054426dc68e5d63aa6a6e9b91ac4ec78e3f3805 (patch) | |
| tree | f13ab8110247ddf2acfd5f68061825f35f877775 /include/trace | |
| parent | function_graph: Have profiler use curr_ret_stack and not depth (diff) | |
| download | linux-dev-3054426dc68e5d63aa6a6e9b91ac4ec78e3f3805.tar.xz linux-dev-3054426dc68e5d63aa6a6e9b91ac4ec78e3f3805.zip | |
sched, trace: Fix prev_state output in sched_switch tracepoint
commit 3f5fe9fef5b2 ("sched/debug: Fix task state recording/printout")
tried to fix the problem introduced by a previous commit efb40f588b43
("sched/tracing: Fix trace_sched_switch task-state printing"). However
the prev_state output in sched_switch is still broken.
task_state_index() uses fls() which considers the LSB as 1. Left
shifting 1 by this value gives an incorrect mapping to the task state.
Fix this by decrementing the value returned by __get_task_state()
before shifting.
Link: http://lkml.kernel.org/r/1540882473-1103-1-git-send-email-pkondeti@codeaurora.org
Cc: stable@vger.kernel.org
Fixes: 3f5fe9fef5b2 ("sched/debug: Fix task state recording/printout")
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/sched.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index f07b270d4fc4..9a4bdfadab07 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -107,6 +107,8 @@ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, #ifdef CREATE_TRACE_POINTS static inline long __trace_sched_switch_state(bool preempt, struct task_struct *p) { + unsigned int state; + #ifdef CONFIG_SCHED_DEBUG BUG_ON(p != current); #endif /* CONFIG_SCHED_DEBUG */ @@ -118,7 +120,15 @@ static inline long __trace_sched_switch_state(bool preempt, struct task_struct * if (preempt) return TASK_REPORT_MAX; - return 1 << task_state_index(p); + /* + * task_state_index() uses fls() and returns a value from 0-8 range. + * Decrement it by 1 (except TASK_RUNNING state i.e 0) before using + * it for left shift operation to get the correct task->state + * mapping. + */ + state = task_state_index(p); + + return state ? (1 << (state - 1)) : state; } #endif /* CREATE_TRACE_POINTS */ |