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authorGregory Haskins <ghaskins@novell.com>2008-03-08 00:10:15 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-03-09 10:05:14 -0700
commit393d94d98b19089ec172566e23557997931b137e (patch)
tree62154269fd93690ffc07ad885cf371542b04ecc5 /kernel/sched.c
parent6efcae460186c0c1c94afff58a92784e1fc0d10b (diff)
downloadop-kernel-dev-393d94d98b19089ec172566e23557997931b137e.zip
op-kernel-dev-393d94d98b19089ec172566e23557997931b137e.tar.gz
cpu hotplug: adjust root-domain->online span in response to hotplug event
We currently set the root-domain online span automatically when the domain is added to the cpu if the cpu is already a member of cpu_online_map. This was done as a hack/bug-fix for s2ram, but it also causes a problem with hotplug CPU_DOWN transitioning. The right way to fix the original problem is to actually respond to CPU_UP events, instead of CPU_ONLINE, which is already too late. This solves the hung reboot regression reported by Andrew Morton and others. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c18
1 files changed, 7 insertions, 11 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 52b9867..b02e4fc 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5813,6 +5813,13 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
/* Must be high prio: stop_machine expects to yield to it. */
rq = task_rq_lock(p, &flags);
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
+
+ /* Update our root-domain */
+ if (rq->rd) {
+ BUG_ON(!cpu_isset(cpu, rq->rd->span));
+ cpu_set(cpu, rq->rd->online);
+ }
+
task_rq_unlock(rq, &flags);
cpu_rq(cpu)->migration_thread = p;
break;
@@ -5821,15 +5828,6 @@ 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
@@ -6105,8 +6103,6 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
rq->rd = rd;
cpu_set(rq->cpu, rd->span);
- if (cpu_isset(rq->cpu, cpu_online_map))
- cpu_set(rq->cpu, rd->online);
for (class = sched_class_highest; class; class = class->next) {
if (class->join_domain)
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