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smp/hotplug: Differentiate the AP-work lockdep class between up and down
With lockdep-crossrelease we get deadlock reports that span cpu-up and cpu-down chains. Such deadlocks cannot possibly happen because cpu-up and cpu-down are globally serialized. CPU0 CPU1 CPU2 cpuhp_up_callbacks: takedown_cpu: cpuhp_thread_fun: cpuhp_state irq_lock_sparse() irq_lock_sparse() wait_for_completion() cpuhp_state complete() Now that we have consistent AP state, we can trivially separate the AP-work class between up and down using st->bringup. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: max.byungchul.park@gmail.com Cc: bigeasy@linutronix.de Cc: efault@gmx.de Cc: rostedt@goodmis.org Link: https://lkml.kernel.org/r/20170920170546.922524234@infradead.org
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parent
724a86881d
commit
5f4b55e106
41
kernel/cpu.c
41
kernel/cpu.c
@ -68,9 +68,26 @@ struct cpuhp_cpu_state {
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static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state);
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#if defined(CONFIG_LOCKDEP) && defined(CONFIG_SMP)
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static struct lock_class_key cpuhp_state_key;
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static struct lockdep_map cpuhp_state_lock_map =
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STATIC_LOCKDEP_MAP_INIT("cpuhp_state", &cpuhp_state_key);
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static struct lockdep_map cpuhp_state_up_map =
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STATIC_LOCKDEP_MAP_INIT("cpuhp_state-up", &cpuhp_state_up_map);
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static struct lockdep_map cpuhp_state_down_map =
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STATIC_LOCKDEP_MAP_INIT("cpuhp_state-down", &cpuhp_state_down_map);
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static void inline cpuhp_lock_acquire(bool bringup)
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{
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lock_map_acquire(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map);
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}
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static void inline cpuhp_lock_release(bool bringup)
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{
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lock_map_release(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map);
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}
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#else
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static void inline cpuhp_lock_acquire(bool bringup) { }
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static void inline cpuhp_lock_release(bool bringup) { }
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#endif
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/**
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@ -486,7 +503,7 @@ static void cpuhp_thread_fun(unsigned int cpu)
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if (WARN_ON_ONCE(!st->should_run))
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return;
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lock_map_acquire(&cpuhp_state_lock_map);
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cpuhp_lock_acquire(bringup);
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if (st->single) {
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state = st->cb_state;
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@ -537,7 +554,7 @@ static void cpuhp_thread_fun(unsigned int cpu)
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}
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next:
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lock_map_release(&cpuhp_state_lock_map);
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cpuhp_lock_release(bringup);
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if (!st->should_run)
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complete(&st->done);
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@ -554,8 +571,11 @@ cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup,
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if (!cpu_online(cpu))
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return 0;
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lock_map_acquire(&cpuhp_state_lock_map);
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lock_map_release(&cpuhp_state_lock_map);
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cpuhp_lock_acquire(false);
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cpuhp_lock_release(false);
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cpuhp_lock_acquire(true);
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cpuhp_lock_release(true);
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/*
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* If we are up and running, use the hotplug thread. For early calls
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@ -593,8 +613,11 @@ static int cpuhp_kick_ap_work(unsigned int cpu)
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enum cpuhp_state prev_state = st->state;
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int ret;
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lock_map_acquire(&cpuhp_state_lock_map);
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lock_map_release(&cpuhp_state_lock_map);
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cpuhp_lock_acquire(false);
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cpuhp_lock_release(false);
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cpuhp_lock_acquire(true);
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cpuhp_lock_release(true);
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trace_cpuhp_enter(cpu, st->target, prev_state, cpuhp_kick_ap_work);
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ret = cpuhp_kick_ap(st, st->target);
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