diff options
| author | Ingo Molnar | 2005-09-10 00:26:12 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2005-09-10 10:06:22 -0700 |
| commit | d79fc0fc6645b0cf5cd980da76942ca6d6300fa4 (patch) | |
| tree | e74aca1df1d37dbd7af66636a4e39a3f7e1af479 | |
| parent | 95cdf3b799a481969a48d69a1a52916ad5da6694 (diff) | |
[PATCH] sched: TASK_NONINTERACTIVE
This patch implements a task state bit (TASK_NONINTERACTIVE), which can be
used by blocking points to mark the task's wait as "non-interactive". This
does not mean the task will be considered a CPU-hog - the wait will simply
not have an effect on the waiting task's priority - positive or negative
alike. Right now only pipe_wait() will make use of it, because it's a
common source of not-so-interactive waits (kernel compilation jobs, etc.).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | fs/pipe.c | 6 | ||||
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/sched.c | 11 |
3 files changed, 16 insertions, 2 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 2c7a23dde2d8..66aa0b938d6a 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -39,7 +39,11 @@ void pipe_wait(struct inode * inode) { DEFINE_WAIT(wait); - prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE); + /* + * Pipes are system-local resources, so sleeping on them + * is considered a noninteractive wait: + */ + prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE); up(PIPE_SEM(*inode)); schedule(); finish_wait(PIPE_WAIT(*inode), &wait); diff --git a/include/linux/sched.h b/include/linux/sched.h index 8a1fcfe80fc7..ac70f845b5b1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -114,6 +114,7 @@ extern unsigned long nr_iowait(void); #define TASK_TRACED 8 #define EXIT_ZOMBIE 16 #define EXIT_DEAD 32 +#define TASK_NONINTERACTIVE 64 #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) diff --git a/kernel/sched.c b/kernel/sched.c index 24eed372d280..6da13bba3e23 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1261,6 +1261,16 @@ out_activate: } /* + * Tasks that have marked their sleep as noninteractive get + * woken up without updating their sleep average. (i.e. their + * sleep is handled in a priority-neutral manner, no priority + * boost and no penalty.) + */ + if (old_state & TASK_NONINTERACTIVE) + __activate_task(p, rq); + else + activate_task(p, rq, cpu == this_cpu); + /* * Sync wakeups (i.e. those types of wakeups where the waker * has indicated that it will leave the CPU in short order) * don't trigger a preemption, if the woken up task will run on @@ -1268,7 +1278,6 @@ out_activate: * the waker guarantees that the freshly woken up task is going * to be considered on this CPU.) */ - activate_task(p, rq, cpu == this_cpu); if (!sync || cpu != this_cpu) { if (TASK_PREEMPTS_CURR(p, rq)) resched_task(rq->curr); |