Commit d79fc0fc authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[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: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 95cdf3b7
......@@ -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);
......
......@@ -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)
......
......@@ -1260,6 +1260,16 @@ out_activate:
p->activated = -1;
}
/*
* 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)
......@@ -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);
......
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