From: Max Kellermann <max.kellermann@gmail.com>
Date: Mon, 30 Sep 2024 09:10:16 +0000 (+0200)
Subject: msg/DispatchQueue: wake up only one dispatch thread
X-Git-Tag: testing/wip-rishabh-testing-20250207.203802~13^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=23fd2cc44864ac793b09d8e60b30cfffe22f0116;p=ceph-ci.git

msg/DispatchQueue: wake up only one dispatch thread

When adding one message, only one thread needs to be woken up.  Waking
up all is a more expensive operation and leads to unnecessary lock
contention and context switches.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---

diff --git a/src/msg/DispatchQueue.cc b/src/msg/DispatchQueue.cc
index b8ed6f7efe8..4694bdff587 100644
--- a/src/msg/DispatchQueue.cc
+++ b/src/msg/DispatchQueue.cc
@@ -93,7 +93,7 @@ void DispatchQueue::enqueue(const ref_t<Message>& m, int priority, uint64_t id)
   } else {
     mqueue.enqueue(id, priority, m->get_cost(), QueueItem(m));
   }
-  cond.notify_all();
+  cond.notify_one();
 }
 
 void DispatchQueue::local_delivery(const ref_t<Message>& m, int priority)