[PATCH] perf sched: fix wrong conversion of task state

From: Tomoki Sekiyama
Date: Wed Jul 27 2016 - 09:15:42 EST


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.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@xxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
tools/perf/builtin-sched.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 0dfe8df..eb2f7f4 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -71,6 +71,7 @@ struct sched_atom {
};

#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
+#define TASK_STATE_MASK 0x7ff

enum thread_state {
THREAD_SLEEPING = 0,
@@ -899,7 +900,7 @@ static char sched_out_state(u64 prev_state)
{
const char *str = TASK_STATE_TO_CHAR_STR;

- return str[prev_state];
+ return str[ffs(prev_state & TASK_STATE_MASK)];
}

static int
--
2.7.4