sched_out_state() converts the prev_state u64 bitmask to a char in
a wrong way, which may cause wrong results of 'perf sched latency'.
This patch fixes the conversion.
Also, preempted tasks must be considered that they are in the
THREAD_WAIT_CPU state.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama...@hitachi.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: David Ahern <dsah...@gmail.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Masami Hiramatsu <mhira...@kernel.org>
---
tools/perf/builtin-sched.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 0dfe8df..8651c36 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -70,7 +70,8 @@ struct sched_atom {
struct task_desc *wakee;
};
-#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
+/* TASK_STATE_MAX means the task is preempted(R+). Use '+' for it here. */
+#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN+"
enum thread_state {
THREAD_SLEEPING = 0,
@@ -897,9 +898,10 @@ static int thread_atoms_insert(struct perf_sched *sched,
struct thread *thread)
static char sched_out_state(u64 prev_state)
{
- const char *str = TASK_STATE_TO_CHAR_STR;
+ const char str[] = TASK_STATE_TO_CHAR_STR;
+ unsigned int bit = prev_state ? __ffs(prev_state) + 1 : 0;
- return str[prev_state];
+ return bit < sizeof(str) - 1 ? str[bit] : '?';
}
static int
@@ -915,7 +917,7 @@ add_sched_out_event(struct work_atoms *atoms,
atom->sched_out_time = timestamp;
- if (run_state == 'R') {
+ if (run_state == 'R' || run_state == '+') {
atom->state = THREAD_WAIT_CPU;
atom->wake_up_time = atom->sched_out_time;
}
--
2.7.4
