---

yaml --- r: 147476 b: refs/heads/master c: c44d70a h: refs/heads/master v: v3
git-mirror · May 19, 2009 · 6f37ca5 · 6f37ca5
1 parent f835224
commit 6f37ca5
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Showing 3 changed files with 11 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 33b2fb303fe7f6b08bbb32f708e67b96eaa94a7a
+refs/heads/master: c44d70a340554a33071339064a303ac0f1a31623
diff --git a/trunk/include/linux/perf_counter.h b/trunk/include/linux/perf_counter.h
@@ -508,6 +508,7 @@ struct perf_counter_context {
 	int			nr_counters;
 	int			nr_active;
 	int			is_active;
+	int			rr_allowed;
 	struct task_struct	*task;
 
 	/*

diff --git a/trunk/kernel/perf_counter.c b/trunk/kernel/perf_counter.c
@@ -1120,7 +1120,8 @@ void perf_counter_task_tick(struct task_struct *curr, int cpu)
 	__perf_counter_task_sched_out(ctx);
 
 	rotate_ctx(&cpuctx->ctx);
-	rotate_ctx(ctx);
+	if (ctx->rr_allowed)
+		rotate_ctx(ctx);
 
 	perf_counter_cpu_sched_in(cpuctx, cpu);
 	perf_counter_task_sched_in(curr, cpu);
@@ -3108,6 +3109,7 @@ __perf_counter_init_context(struct perf_counter_context *ctx,
 	mutex_init(&ctx->mutex);
 	INIT_LIST_HEAD(&ctx->counter_list);
 	INIT_LIST_HEAD(&ctx->event_list);
+	ctx->rr_allowed = 1;
 	ctx->task = task;
 }
 
@@ -3348,6 +3350,9 @@ void perf_counter_init_task(struct task_struct *child)
 	 */
 	mutex_lock(&parent_ctx->mutex);
 
+	parent_ctx->rr_allowed = 0;
+	barrier(); /* irqs */
+
 	/*
 	 * We dont have to disable NMIs - we are only looking at
 	 * the list, not manipulating it:
@@ -3361,6 +3366,9 @@ void perf_counter_init_task(struct task_struct *child)
 			break;
 	}
 
+	barrier(); /* irqs */
+	parent_ctx->rr_allowed = 1;
+
 	mutex_unlock(&parent_ctx->mutex);
 }