nohz: Restore NMI safe local irq work for local nohz kick
The local nohz kick is currently used by perf which needs it to be
NMI-safe. Recent commit though (7d1311b93e
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changed its implementation to fire the local kick using the remote kick
API. It was convenient to make the code more generic but the remote kick
isn't NMI-safe.
As a result:
WARNING: CPU: 3 PID: 18062 at kernel/irq_work.c:72 irq_work_queue_on+0x11e/0x140()
CPU: 3 PID: 18062 Comm: trinity-subchil Not tainted 3.16.0+ #34
0000000000000009 00000000903774d1 ffff880244e06c00 ffffffff9a7f1e37
0000000000000000 ffff880244e06c38 ffffffff9a0791dd ffff880244fce180
0000000000000003 ffff880244e06d58 ffff880244e06ef8 0000000000000000
Call Trace:
<NMI> [<ffffffff9a7f1e37>] dump_stack+0x4e/0x7a
[<ffffffff9a0791dd>] warn_slowpath_common+0x7d/0xa0
[<ffffffff9a07930a>] warn_slowpath_null+0x1a/0x20
[<ffffffff9a17ca1e>] irq_work_queue_on+0x11e/0x140
[<ffffffff9a10a2c7>] tick_nohz_full_kick_cpu+0x57/0x90
[<ffffffff9a186cd5>] __perf_event_overflow+0x275/0x350
[<ffffffff9a184f80>] ? perf_event_task_disable+0xa0/0xa0
[<ffffffff9a01a4cf>] ? x86_perf_event_set_period+0xbf/0x150
[<ffffffff9a187934>] perf_event_overflow+0x14/0x20
[<ffffffff9a020386>] intel_pmu_handle_irq+0x206/0x410
[<ffffffff9a0b54d3>] ? arch_vtime_task_switch+0x63/0x130
[<ffffffff9a01937b>] perf_event_nmi_handler+0x2b/0x50
[<ffffffff9a007b72>] nmi_handle+0xd2/0x390
[<ffffffff9a007aa5>] ? nmi_handle+0x5/0x390
[<ffffffff9a0d131b>] ? lock_release+0xab/0x330
[<ffffffff9a008062>] default_do_nmi+0x72/0x1c0
[<ffffffff9a0c925f>] ? cpuacct_account_field+0xcf/0x200
[<ffffffff9a008268>] do_nmi+0xb8/0x100
Lets fix this by restoring the use of local irq work for the nohz local
kick.
Reported-by: Catalin Iacob <iacobcatalin@gmail.com>
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
parent
69e273c0b0
commit
40bea03959
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@ -183,13 +183,8 @@ static inline bool tick_nohz_full_cpu(int cpu)
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extern void tick_nohz_init(void);
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extern void __tick_nohz_full_check(void);
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extern void tick_nohz_full_kick(void);
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extern void tick_nohz_full_kick_cpu(int cpu);
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static inline void tick_nohz_full_kick(void)
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{
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tick_nohz_full_kick_cpu(smp_processor_id());
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}
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extern void tick_nohz_full_kick_all(void);
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extern void __tick_nohz_task_switch(struct task_struct *tsk);
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#else
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@ -224,6 +224,20 @@ static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
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.func = nohz_full_kick_work_func,
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};
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/*
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* Kick this CPU if it's full dynticks in order to force it to
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* re-evaluate its dependency on the tick and restart it if necessary.
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* This kick, unlike tick_nohz_full_kick_cpu() and tick_nohz_full_kick_all(),
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* is NMI safe.
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*/
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void tick_nohz_full_kick(void)
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{
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if (!tick_nohz_full_cpu(smp_processor_id()))
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return;
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irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
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}
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/*
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* Kick the CPU if it's full dynticks in order to force it to
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* re-evaluate its dependency on the tick and restart it if necessary.
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