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-rw-r--r--kernel/events/core.c42
1 files changed, 31 insertions, 11 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 49a5118f3564..39cf4a40aa4c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5683,6 +5683,17 @@ perf_event_aux_ctx(struct perf_event_context *ctx,
}
static void
+perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data,
+ struct perf_event_context *task_ctx)
+{
+ rcu_read_lock();
+ preempt_disable();
+ perf_event_aux_ctx(task_ctx, output, data);
+ preempt_enable();
+ rcu_read_unlock();
+}
+
+static void
perf_event_aux(perf_event_aux_output_cb output, void *data,
struct perf_event_context *task_ctx)
{
@@ -5691,14 +5702,23 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
struct pmu *pmu;
int ctxn;
+ /*
+ * If we have task_ctx != NULL we only notify
+ * the task context itself. The task_ctx is set
+ * only for EXIT events before releasing task
+ * context.
+ */
+ if (task_ctx) {
+ perf_event_aux_task_ctx(output, data, task_ctx);
+ return;
+ }
+
rcu_read_lock();
list_for_each_entry_rcu(pmu, &pmus, entry) {
cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
if (cpuctx->unique_pmu != pmu)
goto next;
perf_event_aux_ctx(&cpuctx->ctx, output, data);
- if (task_ctx)
- goto next;
ctxn = pmu->task_ctx_nr;
if (ctxn < 0)
goto next;
@@ -5708,12 +5728,6 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
next:
put_cpu_ptr(pmu->pmu_cpu_context);
}
-
- if (task_ctx) {
- preempt_disable();
- perf_event_aux_ctx(task_ctx, output, data);
- preempt_enable();
- }
rcu_read_unlock();
}
@@ -8803,10 +8817,8 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
struct perf_event_context *child_ctx, *clone_ctx = NULL;
unsigned long flags;
- if (likely(!child->perf_event_ctxp[ctxn])) {
- perf_event_task(child, NULL, 0);
+ if (likely(!child->perf_event_ctxp[ctxn]))
return;
- }
local_irq_save(flags);
/*
@@ -8890,6 +8902,14 @@ void perf_event_exit_task(struct task_struct *child)
for_each_task_context_nr(ctxn)
perf_event_exit_task_context(child, ctxn);
+
+ /*
+ * The perf_event_exit_task_context calls perf_event_task
+ * with child's task_ctx, which generates EXIT events for
+ * child contexts and sets child->perf_event_ctxp[] to NULL.
+ * At this point we need to send EXIT events to cpu contexts.
+ */
+ perf_event_task(child, NULL, 0);
}
static void perf_free_event(struct perf_event *event,