On Fri, 21 Jun 2002, Alan Cox wrote:
> > What's going on with the kernel community? I posted a similar fix for
> > the 2.4.18 kernel, and it hasn't been picked up there either.
>
> I've not seen that one. However the -ac tree uses a different scheduler
> anyway. You should check if 2.4.19pre has the same problem and if so
> mail Marcelo directly a patch
the O(1) scheduler does not have this problem, so the -ac tree is ok.
for vanilla 2.4.18/2.4.19-pre i've created a compromise patch which
reduces the impact and fixes RT behavior (attached). There was no further
comment from Bhavesh, so i assumed it's all a done deal ... Marcelo,
please apply.
Ingo
--- linux/kernel/sched.c.orig Thu Jun 13 20:14:31 2002
+++ linux/kernel/sched.c Thu Jun 13 23:33:41 2002
@@ -324,7 +324,10 @@
*/
static inline void add_to_runqueue(struct task_struct * p)
{
- list_add(&p->run_list, &runqueue_head);
+ if (p->policy == SCHED_OTHER)
+ list_add(&p->run_list, &runqueue_head);
+ else
+ list_add_tail(&p->run_list, &runqueue_head);
nr_running++;
}
@@ -334,12 +337,6 @@
list_add_tail(&p->run_list, &runqueue_head);
}
-static inline void move_first_runqueue(struct task_struct * p)
-{
- list_del(&p->run_list);
- list_add(&p->run_list, &runqueue_head);
-}
-
/*
* Wake up a process. Put it on the run-queue if it's not
* already there. The "current" process is always on the
@@ -955,9 +952,6 @@
retval = 0;
p->policy = policy;
p->rt_priority = lp.sched_priority;
- if (task_on_runqueue(p))
- move_first_runqueue(p);
-
current->need_resched = 1;
out_unlock:
--- linux/kernel/timer.c.orig Thu Jun 13 20:17:04 2002
+++ linux/kernel/timer.c Thu Jun 13 20:23:15 2002
@@ -585,7 +585,8 @@
if (p->pid) {
if (--p->counter <= 0) {
p->counter = 0;
- p->need_resched = 1;
+ if (p->policy != SCHED_FIFO)
+ p->need_resched = 1;
}
if (p->nice > 0)
kstat.per_cpu_nice[cpu] += user_tick;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Jun 23 2002 - 22:00:26 EST