From: Olivier Houchard <ohouchard@haproxy.com>
Date: Thu, 18 Apr 2019 12:12:51 +0000 (+0200)
Subject: MEDIUM: tasks: Use __ha_barrier_store after modifying global_tasks_mask.
X-Git-Tag: v2.0-dev3~226
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ed1a6a0d8a50f8b4b4819121de7f0eaf6927273f;p=thirdparty%2Fhaproxy.git

MEDIUM: tasks: Use __ha_barrier_store after modifying global_tasks_mask.

Now that we no longer use atomic operations to update global_tasks_mask,
as it's always modified while holding the TASK_RQ_LOCK, we have to use
__ha_barrier_store() instead of __ha_barrier_atomic_store() to ensure
any modification of global_tasks_mask is seen before modifying
active_tasks_mask.

This should be backported to 1.9.
---

diff --git a/src/task.c b/src/task.c
index b4f65e892a..de6eda1e72 100644
--- a/src/task.c
+++ b/src/task.c
@@ -78,7 +78,7 @@ void __task_wakeup(struct task *t, struct eb_root *root)
 #ifdef USE_THREAD
 	if (root == &rqueue) {
 		global_tasks_mask |= t->thread_mask;
-		__ha_barrier_atomic_store();
+		__ha_barrier_store();
 	}
 #endif
 	_HA_ATOMIC_OR(&active_tasks_mask, t->thread_mask);