perf: Sanitize the RCU logic
Simplify things and simply synchronize against two RCU variants for PMU unregister -- we don't care about performance, its module unload if anything. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Родитель
b0b2072df3
Коммит
cde8e88498
|
@ -3810,7 +3810,7 @@ static void perf_event_task_event(struct perf_task_event *task_event)
|
|||
struct pmu *pmu;
|
||||
int ctxn;
|
||||
|
||||
rcu_read_lock_sched();
|
||||
rcu_read_lock();
|
||||
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
||||
cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
|
||||
perf_event_task_ctx(&cpuctx->ctx, task_event);
|
||||
|
@ -3825,7 +3825,7 @@ static void perf_event_task_event(struct perf_task_event *task_event)
|
|||
if (ctx)
|
||||
perf_event_task_ctx(ctx, task_event);
|
||||
}
|
||||
rcu_read_unlock_sched();
|
||||
rcu_read_unlock();
|
||||
}
|
||||
|
||||
static void perf_event_task(struct task_struct *task,
|
||||
|
@ -3943,7 +3943,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
|
|||
|
||||
comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
|
||||
|
||||
rcu_read_lock_sched();
|
||||
rcu_read_lock();
|
||||
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
||||
cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
|
||||
perf_event_comm_ctx(&cpuctx->ctx, comm_event);
|
||||
|
@ -3956,7 +3956,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
|
|||
if (ctx)
|
||||
perf_event_comm_ctx(ctx, comm_event);
|
||||
}
|
||||
rcu_read_unlock_sched();
|
||||
rcu_read_unlock();
|
||||
}
|
||||
|
||||
void perf_event_comm(struct task_struct *task)
|
||||
|
@ -4126,7 +4126,7 @@ got_name:
|
|||
|
||||
mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
|
||||
|
||||
rcu_read_lock_sched();
|
||||
rcu_read_lock();
|
||||
list_for_each_entry_rcu(pmu, &pmus, entry) {
|
||||
cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
|
||||
perf_event_mmap_ctx(&cpuctx->ctx, mmap_event,
|
||||
|
@ -4142,7 +4142,7 @@ got_name:
|
|||
vma->vm_flags & VM_EXEC);
|
||||
}
|
||||
}
|
||||
rcu_read_unlock_sched();
|
||||
rcu_read_unlock();
|
||||
|
||||
kfree(buf);
|
||||
}
|
||||
|
@ -5218,10 +5218,11 @@ void perf_pmu_unregister(struct pmu *pmu)
|
|||
mutex_unlock(&pmus_lock);
|
||||
|
||||
/*
|
||||
* We use the pmu list either under SRCU or preempt_disable,
|
||||
* synchronize_srcu() implies synchronize_sched() so we're good.
|
||||
* We dereference the pmu list under both SRCU and regular RCU, so
|
||||
* synchronize against both of those.
|
||||
*/
|
||||
synchronize_srcu(&pmus_srcu);
|
||||
synchronize_rcu();
|
||||
|
||||
free_percpu(pmu->pmu_disable_count);
|
||||
free_pmu_context(pmu->pmu_cpu_context);
|
||||
|
|
Загрузка…
Ссылка в новой задаче