Revert "CPU hotplug, cpusets, suspend: Don't touch cpusets during suspend/resume"

4293f20c · Linus Torvalds <[email protected]> · 2012-03-07 08:21:19 -08:00

This reverts commit 8f2f748b0656257153bcf0941df8d6060acc5ca6.

It causes some odd regression that we have not figured out, and it's too
late in the -rc series to try to figure it out now.

As reported by Konstantin Khlebnikov, it causes consistent hangs on his
laptop (Thinkpad x220: 2x cores + HT).  They can be avoided by adding
calls to "rebuild_sched_domains();" in cpuset_cpu_[in]active() for the
CPU_{ONLINE/DOWN_FAILED/DOWN_PREPARE}_FROZEN cases, but it's not at all
clear why, and it makes no sense.

Konstantin's config doesn't even have CONFIG_CPUSETS enabled, just to
make things even more interesting.  So it's not the cpusets, it's just
the scheduling domains.

So until this is understood, revert.

Bisected-reported-and-tested-by: Konstantin Khlebnikov <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Acked-by: Srivatsa S. Bhat <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 4293f20c19f44ca66e5ac836b411d25e14b9f185
Parents: dac12d1f

Changes

1 files changed · +2 −2

File	Status	Add	Del	Content
kernel/sched/core.c	modified	+2	−2	View file

kernel/sched/core.c

View file

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 33a0676..b342f57 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6728,7 +6728,7 @@ int __init sched_create_sysfs_power_savings_entries(struct device *dev)
 static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
 			     void *hcpu)
 {
-	switch (action) {
+	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_ONLINE:
 	case CPU_DOWN_FAILED:
 		cpuset_update_active_cpus();
@@ -6741,7 +6741,7 @@ static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
 static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
 			       void *hcpu)
 {
-	switch (action) {
+	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_DOWN_PREPARE:
 		cpuset_update_active_cpus();
 		return NOTIFY_OK;