Messages in this thread Patch in this message | | | From | Gregory Haskins <> | Subject | [PATCH 2/4] SCHED: Track online cpus in the root-domain | Date | Wed, 21 Nov 2007 14:52:06 -0500 |
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We cache the subset of rd->span cpus that are online in rd->online to reduce the need for runtime computation.
Signed-off-by: Gregory Haskins <ghaskins@novell.com> ---
kernel/sched.c | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c index e5c902c..c58d1bf 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -281,6 +281,7 @@ struct rt_rq { struct root_domain { atomic_t refcount; cpumask_t span; + cpumask_t online; }; static struct root_domain def_root_domain; @@ -5491,6 +5492,15 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_ONLINE_FROZEN: /* Strictly unnecessary, as first user will wake it. */ wake_up_process(cpu_rq(cpu)->migration_thread); + + /* Update our root-domain */ + rq = cpu_rq(cpu); + spin_lock_irqsave(&rq->lock, flags); + if (rq->rd) { + BUG_ON(!cpu_isset(cpu, rq->rd->span)); + cpu_set(cpu, rq->rd->online); + } + spin_unlock_irqrestore(&rq->lock, flags); break; #ifdef CONFIG_HOTPLUG_CPU @@ -5539,6 +5549,17 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) } spin_unlock_irq(&rq->lock); break; + + case CPU_DOWN_PREPARE: + /* Update our root-domain */ + rq = cpu_rq(cpu); + spin_lock_irqsave(&rq->lock, flags); + if (rq->rd) { + BUG_ON(!cpu_isset(cpu, rq->rd->span)); + cpu_clear(cpu, rq->rd->online); + } + spin_unlock_irqrestore(&rq->lock, flags); + break; #endif case CPU_LOCK_RELEASE: mutex_unlock(&sched_hotcpu_mutex); @@ -5763,6 +5784,7 @@ static void init_rootdomain(struct root_domain *rd, cpumask_t *map) memset(rd, 0, sizeof(*rd)); rd->span = *map; + cpus_and(rd->online, rd->span, cpu_online_map); } static void init_defrootdomain(void) - 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/
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