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-rw-r--r--kernel/perf_counter.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 66ab1e9d1294..d55a50da2347 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1429,6 +1429,53 @@ void perf_counter_task_tick(struct task_struct *curr, int cpu)
}
/*
+ * Enable all of a task's counters that have been marked enable-on-exec.
+ * This expects task == current.
+ */
+static void perf_counter_enable_on_exec(struct task_struct *task)
+{
+ struct perf_counter_context *ctx;
+ struct perf_counter *counter;
+ unsigned long flags;
+ int enabled = 0;
+
+ local_irq_save(flags);
+ ctx = task->perf_counter_ctxp;
+ if (!ctx || !ctx->nr_counters)
+ goto out;
+
+ __perf_counter_task_sched_out(ctx);
+
+ spin_lock(&ctx->lock);
+
+ list_for_each_entry(counter, &ctx->counter_list, list_entry) {
+ if (!counter->attr.enable_on_exec)
+ continue;
+ counter->attr.enable_on_exec = 0;
+ if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
+ continue;
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->tstamp_enabled =
+ ctx->time - counter->total_time_enabled;
+ enabled = 1;
+ }
+
+ /*
+ * Unclone this context if we enabled any counter.
+ */
+ if (enabled && ctx->parent_ctx) {
+ put_ctx(ctx->parent_ctx);
+ ctx->parent_ctx = NULL;
+ }
+
+ spin_unlock(&ctx->lock);
+
+ perf_counter_task_sched_in(task, smp_processor_id());
+ out:
+ local_irq_restore(flags);
+}
+
+/*
* Cross CPU call to read the hardware counter
*/
static void __perf_counter_read(void *info)
@@ -2949,6 +2996,9 @@ void perf_counter_comm(struct task_struct *task)
{
struct perf_comm_event comm_event;
+ if (task->perf_counter_ctxp)
+ perf_counter_enable_on_exec(task);
+
if (!atomic_read(&nr_comm_counters))
return;