From 4293f20c19f44ca66e5ac836b411d25e14b9f185 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 7 Mar 2012 08:21:19 -0800 Subject: [PATCH] Revert "CPU hotplug, cpusets, suspend: Don't touch cpusets during suspend/resume" 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 Acked-by: Peter Zijlstra Acked-by: Ingo Molnar Acked-by: Srivatsa S. Bhat Signed-off-by: Linus Torvalds --- kernel/sched/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 33a0676ea74..b342f57879e 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; -- 2.20.1