[PATCH] sched: make task_noninteractive use sleep_type
Alterations to the pipe code in the kernel made it possible for relative
starvation to occur with tasks that slept waiting on a pipe getting unfair
priority bonuses even if they were otherwise fully cpu bound so the
TASK_NONINTERACTIVE flag was introduced which prevented any change to
sleep_avg while sleeping waiting on a pipe. This change also leads to the
converse though, preventing any priority boost from occurring in truly
interactive tasks that wait on pipes.
Convert the TASK_NONINTERACTIVE flag to set sleep_type to SLEEP_NONINTERACTIVE
which will allow a linear bonus to priority based on sleep time thus allowing
interactive tasks to get high priority if they sleep enough.
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sched.c b/kernel/sched.c
index f55ce5a..589e55a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1273,18 +1273,18 @@
* sleep_avg beyond just interactive state.
*/
p->sleep_type = SLEEP_NONINTERACTIVE;
- }
+ } else
/*
* 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.)
+ * woken up with their sleep average not weighted in an
+ * interactive way.
*/
- if (old_state & TASK_NONINTERACTIVE)
- __activate_task(p, rq);
- else
- activate_task(p, rq, cpu == this_cpu);
+ if (old_state & TASK_NONINTERACTIVE)
+ p->sleep_type = SLEEP_NONINTERACTIVE;
+
+
+ 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)