diff options
| author | Oleg Nesterov | 2014-01-23 15:55:35 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2014-01-23 16:37:01 -0800 |
| commit | 74e37200de8e9c4e09b70c21c3f13c2071e77457 (patch) | |
| tree | de7db4aa1113562665ba7f72d92ef33be788f7b7 | |
| parent | 942be3875a1931c379bbc37053829dd6847e0f3f (diff) | |
proc: cleanup/simplify get_task_state/task_state_array
get_task_state() and task_state_array[] look confusing and suboptimal, it
is not clear what it can actually report to user-space and
task_state_array[] blows .data for no reason.
1. state = (tsk->state & TASK_REPORT) | tsk->exit_state is not
clear. TASK_REPORT is self-documenting but it is not clear
what ->exit_state can add.
Move the potential exit_state's (EXIT_ZOMBIE and EXIT_DEAD)
into TASK_REPORT and use it to calculate the final result.
2. With the change above it is obvious that task_state_array[]
has the unused entries just to make BUILD_BUG_ON() happy.
Change this BUILD_BUG_ON() to use TASK_REPORT rather than
TASK_STATE_MAX and shrink task_state_array[].
3. Turn the "while (state)" loop into fls(state).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/proc/array.c | 15 | ||||
| -rw-r--r-- | include/linux/sched.h | 2 |
2 files changed, 4 insertions, 13 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 1bd2077187fd..554a0b229ac2 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -140,24 +140,15 @@ static const char * const task_state_array[] = { "t (tracing stop)", /* 8 */ "Z (zombie)", /* 16 */ "X (dead)", /* 32 */ - "x (dead)", /* 64 */ - "K (wakekill)", /* 128 */ - "W (waking)", /* 256 */ - "P (parked)", /* 512 */ }; static inline const char *get_task_state(struct task_struct *tsk) { - unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state; - const char * const *p = &task_state_array[0]; + unsigned int state = (tsk->state | tsk->exit_state) & TASK_REPORT; - BUILD_BUG_ON(1 + ilog2(TASK_STATE_MAX) != ARRAY_SIZE(task_state_array)); + BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array)-1); - while (state) { - p++; - state >>= 1; - } - return *p; + return task_state_array[fls(state)]; } static inline void task_state(struct seq_file *m, struct pid_namespace *ns, diff --git a/include/linux/sched.h b/include/linux/sched.h index cf9e414dbb9e..33e4e9e1f621 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -229,7 +229,7 @@ extern char ___assert_task_state[1 - 2*!!( /* get_task_state() */ #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ - __TASK_TRACED) + __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD) #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0) #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0) |