From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Sat, 26 Sep 2009 22:26:50 +0000 (-0400)
Subject: Don't mark reader thread as being waited for if non-contended
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=b648196904a64362f7b24c85effd23150a30ce1c;p=userspace-rcu.git

Don't mark reader thread as being waited for if non-contended

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---

diff --git a/urcu.c b/urcu.c
index a9ebf59..f74304c 100644
--- a/urcu.c
+++ b/urcu.c
@@ -220,6 +220,10 @@ void wait_for_quiescent_state(void)
 	for (index = registry; index < registry + num_readers; index++) {
 		int wait_loops = 0;
 
+		if (likely(!rcu_old_gp_ongoing(
+				&index->urcu_reader_status->active_readers)))
+			continue;
+
 		index->urcu_reader_status->gp_waiting = 1;
 #ifndef HAS_INCOHERENT_CACHES
 		while (rcu_old_gp_ongoing(