sched: Assert task state bits at build time

Since everybody is lazy and prone to forgetting things, make the
compiler help us a bit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121830.060186433@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-12-17 13:16:30 +01:00 committed by Ingo Molnar
parent 464763cf1c
commit e1781538cf
2 changed files with 14 additions and 8 deletions

View File

@ -134,14 +134,14 @@ static inline void task_name(struct seq_file *m, struct task_struct *p)
* simple bit tests.
*/
static const char *task_state_array[] = {
"R (running)", /* 0 */
"S (sleeping)", /* 1 */
"D (disk sleep)", /* 2 */
"T (stopped)", /* 4 */
"t (tracing stop)", /* 8 */
"Z (zombie)", /* 16 */
"X (dead)", /* 32 */
"x (dead)", /* 64 */
"R (running)", /* 0 */
"S (sleeping)", /* 1 */
"D (disk sleep)", /* 2 */
"T (stopped)", /* 4 */
"t (tracing stop)", /* 8 */
"Z (zombie)", /* 16 */
"X (dead)", /* 32 */
"x (dead)", /* 64 */
"K (wakekill)", /* 128 */
"W (waking)", /* 256 */
};
@ -151,6 +151,8 @@ static inline const char *get_task_state(struct task_struct *tsk)
unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state;
const char **p = &task_state_array[0];
BUILD_BUG_ON(1 + ilog2(TASK_STATE_MAX) != ARRAY_SIZE(task_state_array));
while (state) {
p++;
state >>= 1;

View File

@ -192,9 +192,13 @@ print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
#define TASK_DEAD 64
#define TASK_WAKEKILL 128
#define TASK_WAKING 256
#define TASK_STATE_MAX 512
#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
extern char ___assert_task_state[1 - 2*!!(
sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
/* Convenience macros for the sake of set_task_state */
#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)