Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d5f9f942c601fdebe57f7805e4b4fbad9c28ada8
Commit: d5f9f942c601fdebe57f7805e4b4fbad9c28ada8
Parent: da4e8ca376a1b3dca470eba14dcec321a6a27b8b
Author: Andrew Morton <[EMAIL PROTECTED]>
AuthorDate: Tue May 8 20:27:06 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Tue May 8 20:41:15 2007 -0700
revert 'sched: redundant reschedule when set_user_nice() boosts a prio of a
task from the "expired" array'
Revert commit bd53f96ca54a21c07e7a0ae1886fa623d370b85f.
Con says:
This is no good, sorry. The one I saw originally was with the staircase
deadline cpu scheduler in situ and was different.
#define TASK_PREEMPTS_CURR(p, rq) \
((p)->prio < (rq)->curr->prio)
(((p)->prio < (rq)->curr->prio) && ((p)->array == (rq)->active))
This will fail to wake up a runqueue for a task that has been migrated to
the
expired array of a runqueue which is otherwise idle which can happen with
smp
balancing,
Cc: Dmitry Adamushko <[EMAIL PROTECTED]>
Cc: Con Kolivas <[EMAIL PROTECTED]>
Cc: Ingo Molnar <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
kernel/sched.c | 34 ++++++++++++++++++----------------
1 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index a3a0408..66bd7ff 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -169,7 +169,7 @@ unsigned long long __attribute__((weak)) sched_clock(void)
(MAX_BONUS / 2 + DELTA((p)) + 1) / MAX_BONUS - 1))
#define TASK_PREEMPTS_CURR(p, rq) \
- (((p)->prio < (rq)->curr->prio) && ((p)->array == (rq)->active))
+ ((p)->prio < (rq)->curr->prio)
#define SCALE_PRIO(x, prio) \
max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_TIMESLICE)
@@ -4076,13 +4076,13 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
struct prio_array *array;
unsigned long flags;
struct rq *rq;
- int delta;
+ int oldprio;
BUG_ON(prio < 0 || prio > MAX_PRIO);
rq = task_rq_lock(p, &flags);
- delta = prio - p->prio;
+ oldprio = p->prio;
array = p->array;
if (array)
dequeue_task(p, array);
@@ -4098,11 +4098,13 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
enqueue_task(p, array);
/*
* Reschedule if we are currently running on this runqueue and
- * our priority decreased, or if our priority became higher
- * than the current's.
+ * our priority decreased, or if we are not currently running on
+ * this runqueue and our priority is higher than the current's
*/
- if (TASK_PREEMPTS_CURR(p, rq) ||
- (delta > 0 && task_running(rq, p)))
+ if (task_running(rq, p)) {
+ if (p->prio > oldprio)
+ resched_task(rq->curr);
+ } else if (TASK_PREEMPTS_CURR(p, rq))
resched_task(rq->curr);
}
task_rq_unlock(rq, &flags);
@@ -4150,12 +4152,10 @@ void set_user_nice(struct task_struct *p, long nice)
enqueue_task(p, array);
inc_raw_weighted_load(rq, p);
/*
- * Reschedule if we are currently running on this runqueue and
- * our priority decreased, or if our priority became higher
- * than the current's.
+ * If the task increased its priority or is running and
+ * lowered its priority, then reschedule its CPU:
*/
- if (TASK_PREEMPTS_CURR(p, rq) ||
- (delta > 0 && task_running(rq, p)))
+ if (delta < 0 || (delta > 0 && task_running(rq, p)))
resched_task(rq->curr);
}
out_unlock:
@@ -4382,11 +4382,13 @@ recheck:
__activate_task(p, rq);
/*
* Reschedule if we are currently running on this runqueue and
- * our priority decreased, or our priority became higher
- * than the current's.
+ * our priority decreased, or if we are not currently running on
+ * this runqueue and our priority is higher than the current's
*/
- if (TASK_PREEMPTS_CURR(p, rq) ||
- (task_running(rq, p) && p->prio > oldprio))
+ if (task_running(rq, p)) {
+ if (p->prio > oldprio)
+ resched_task(rq->curr);
+ } else if (TASK_PREEMPTS_CURR(p, rq))
resched_task(rq->curr);
}
__task_rq_unlock(rq);
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
