diff options
| author | Gregory Haskins <ghaskins@novell.com> | 2009-07-30 10:57:23 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-02 14:26:12 +0200 |
| commit | 00aec93d10a051ea64f83eff75d4065a19508ea6 (patch) | |
| tree | 010148caeaf4d4b36188ba15828343aa6c74efc9 | |
| parent | 3f029d3c6d62068d59301d90c18dbde8ee402107 (diff) | |
| download | lwn-00aec93d10a051ea64f83eff75d4065a19508ea6.tar.gz lwn-00aec93d10a051ea64f83eff75d4065a19508ea6.zip | |
sched: Fully integrate cpus_active_map and root-domain code
Reflect "active" cpus in the rq->rd->online field, instead of
the online_map.
The motivation is that things that use the root-domain code
(such as cpupri) only care about cpus classified as "active"
anyway. By synchronizing the root-domain state with the active
map, we allow several optimizations.
For instance, we can remove an extra cpumask_and from the
scheduler hotpath by utilizing rq->rd->online (since it is now
a cached version of cpu_active_map & rq->rd->span).
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090730145723.25226.24493.stgit@dev.haskins.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/sched.c | 2 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 10 | ||||
| -rw-r--r-- | kernel/sched_rt.c | 7 |
3 files changed, 8 insertions, 11 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 613fee54fc89..475138c42548 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7927,7 +7927,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd) rq->rd = rd; cpumask_set_cpu(rq->cpu, rd->span); - if (cpumask_test_cpu(rq->cpu, cpu_online_mask)) + if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) set_rq_online(rq); spin_unlock_irqrestore(&rq->lock, flags); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 652e8bdef9aa..493472984879 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1046,17 +1046,21 @@ static void yield_task_fair(struct rq *rq) * search starts with cpus closest then further out as needed, * so we always favor a closer, idle cpu. * Domains may include CPUs that are not usable for migration, - * hence we need to mask them out (cpu_active_mask) + * hence we need to mask them out (rq->rd->online) * * Returns the CPU we should wake onto. */ #if defined(ARCH_HAS_SCHED_WAKE_IDLE) + +#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online) + static int wake_idle(int cpu, struct task_struct *p) { struct sched_domain *sd; int i; unsigned int chosen_wakeup_cpu; int this_cpu; + struct rq *task_rq = task_rq(p); /* * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu @@ -1089,10 +1093,10 @@ static int wake_idle(int cpu, struct task_struct *p) for_each_domain(cpu, sd) { if ((sd->flags & SD_WAKE_IDLE) || ((sd->flags & SD_WAKE_IDLE_FAR) - && !task_hot(p, task_rq(p)->clock, sd))) { + && !task_hot(p, task_rq->clock, sd))) { for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) { - if (cpu_active(i) && idle_cpu(i)) { + if (cpu_rd_active(i, task_rq) && idle_cpu(i)) { if (i != task_cpu(p)) { schedstat_inc(p, se.nr_wakeups_idle); diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index a8f89bc3e5eb..13f728ef5b38 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1173,13 +1173,6 @@ static int find_lowest_rq(struct task_struct *task) return -1; /* No targets found */ /* - * Only consider CPUs that are usable for migration. - * I guess we might want to change cpupri_find() to ignore those - * in the first place. - */ - cpumask_and(lowest_mask, lowest_mask, cpu_active_mask); - - /* * At this point we have built a mask of cpus representing the * lowest priority tasks in the system. Now we want to elect * the best one based on our affinity and topology. |