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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-11-12 15:55:29 +0100
committerIngo Molnar <mingo@elte.hu>2009-11-13 10:09:59 +0100
commitfe3bcfe1f6c1fc4ea7706ac2d05e579fd9092682 (patch)
tree2de57bbb385face039f7e6c0da38f86e545076a0 /kernel/sched_fair.c
parenta50bde5130f65733142b32975616427d0ea50856 (diff)
sched: More generic WAKE_AFFINE vs select_idle_sibling()
Instead of only considering SD_WAKE_AFFINE | SD_PREFER_SIBLING domains also allow all SD_PREFER_SIBLING domains below a SD_WAKE_AFFINE domain to change the affinity target. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091112145610.909723612@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c33
1 files changed, 16 insertions, 17 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index a32df152474..f28a2671a1a 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1333,20 +1333,16 @@ select_idle_sibling(struct task_struct *p, struct sched_domain *sd, int target)
* test in select_task_rq_fair) and the prev_cpu is idle then that's
* always a better target than the current cpu.
*/
- if (target == cpu) {
- if (!cpu_rq(prev_cpu)->cfs.nr_running)
- target = prev_cpu;
- }
+ if (target == cpu && !cpu_rq(prev_cpu)->cfs.nr_running)
+ return prev_cpu;
/*
* Otherwise, iterate the domain and find an elegible idle cpu.
*/
- if (target == -1 || target == cpu) {
- for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
- if (!cpu_rq(i)->cfs.nr_running) {
- target = i;
- break;
- }
+ for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
+ if (!cpu_rq(i)->cfs.nr_running) {
+ target = i;
+ break;
}
}
@@ -1407,7 +1403,12 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
want_sd = 0;
}
- if (want_affine && (tmp->flags & SD_WAKE_AFFINE)) {
+ /*
+ * While iterating the domains looking for a spanning
+ * WAKE_AFFINE domain, adjust the affine target to any idle cpu
+ * in cache sharing domains along the way.
+ */
+ if (want_affine) {
int target = -1;
/*
@@ -1420,17 +1421,15 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
/*
* If there's an idle sibling in this domain, make that
* the wake_affine target instead of the current cpu.
- *
- * XXX: should we possibly do this outside of
- * WAKE_AFFINE, in case the shared cache domain is
- * smaller than the WAKE_AFFINE domain?
*/
if (tmp->flags & SD_PREFER_SIBLING)
target = select_idle_sibling(p, tmp, target);
if (target >= 0) {
- affine_sd = tmp;
- want_affine = 0;
+ if (tmp->flags & SD_WAKE_AFFINE) {
+ affine_sd = tmp;
+ want_affine = 0;
+ }
cpu = target;
}
}