[PATCH RESEND v4] sched: fix llc shared map unreleased during cpu hotplug

[Wanpeng Li]

[  220.262245] Call Trace:
[  220.262252]  [<ffffffff810e8396>] load_balance+0x156/0x980
[  220.262259]  [<ffffffff816eeffe>] ? _raw_spin_unlock_irqrestore+0x2e/0xa0
[  220.262266]  [<ffffffff810e9aa3>] idle_balance+0xe3/0x150
[  220.262270]  [<ffffffff816ec4e7>] __schedule+0x797/0x8d0
[  220.262277]  [<ffffffff816ec934>] schedule+0x24/0x70
[  220.262283]  [<ffffffff816e9cd9>] schedule_timeout+0x119/0x1f0
[  220.262294]  [<ffffffff810bb6e0>] ? lock_timer_base+0x70/0x70
[  220.262301]  [<ffffffff816e9dc9>] schedule_timeout_uninterruptible+0x19/0x20
[  220.262308]  [<ffffffff810bd3e8>] msleep+0x18/0x20
[  220.262317]  [<ffffffff813aa11a>] lock_device_hotplug_sysfs+0x2a/0x50
[  220.262323]  [<ffffffff813aa16e>] online_store+0x2e/0x80
[  220.262358]  [<ffffffff813a873b>] dev_attr_store+0x1b/0x20

Last level cache shared map is built during cpu up and build sched domain 
routine takes advantage of it to setup sched domain cpu topology, however, 
llc shared map is unreleased during cpu disable which lead to invalid sched 
domain cpu topology. This patch fix it by release llc shared map correctly
during cpu disable.

Reviewed-by: Toshi Kani <toshi.kani@xxxxxx>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Tested-by: Linn Crosetto <linn@xxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
---
v3 -> v4:
 * simplify backtrace
v2 -> v3:
 * simplify backtrace 
v1 -> v2:
 * fix subject line

 arch/x86/kernel/smpboot.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5492798..0134ec7 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1292,6 +1292,9 @@ static void remove_siblinginfo(int cpu)
 
 	for_each_cpu(sibling, cpu_sibling_mask(cpu))
 		cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling));
+	for_each_cpu(sibling, cpu_llc_shared_mask(cpu))
+		cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling));
+	cpumask_clear(cpu_llc_shared_mask(cpu));
 	cpumask_clear(cpu_sibling_mask(cpu));
 	cpumask_clear(cpu_core_mask(cpu));
 	c->phys_proc_id = 0;
-- 
1.9.1

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