Messages in this thread Patch in this message | | | From | Tomoki Sekiyama <> | Subject | [PATCH v2] perf sched: fix wrong conversion of task state | Date | Thu, 28 Jul 2016 01:07:40 +0900 |
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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.qu@hitachi.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Masami Hiramatsu <mhiramat@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
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