From: Willy Tarreau <w@1wt.eu>
Date: Wed, 1 Jul 2020 14:39:33 +0000 (+0200)
Subject: MEDIUM: mux-fcgi: use task_kill() during fcgi_takeover() instead of task_wakeup()
X-Git-Tag: v2.2-dev12~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=88d18f81aed369da4ca2f1334a2c06d2c6f66f35;p=thirdparty%2Fhaproxy.git

MEDIUM: mux-fcgi: use task_kill() during fcgi_takeover() instead of task_wakeup()

task_wakeup() passes the task through the global run queue under the
global RQ lock, which is expensive when dealing with large amounts of
fcgi_takeover() calls. Let's use the new task_kill() instead to kill the
task.
---

diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index b09ad566c2..bd27a63f00 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -4082,6 +4082,7 @@ static void fcgi_show_fd(struct buffer *msg, struct connection *conn)
 static int fcgi_takeover(struct connection *conn)
 {
 	struct fcgi_conn *fcgi = conn->ctx;
+	struct task *task;
 
 	if (fd_takeover(conn->handle.fd, conn) != 0)
 		return -1;
@@ -4093,10 +4094,13 @@ static int fcgi_takeover(struct connection *conn)
 	 */
 	fcgi->wait_event.tasklet->context = NULL;
 	tasklet_wakeup(fcgi->wait_event.tasklet);
-	if (fcgi->task) {
-		fcgi->task->context = NULL;
-		/* Wake the task, to let it free itself */
-		task_wakeup(fcgi->task, TASK_WOKEN_OTHER);
+
+	task = fcgi->task;
+	if (task) {
+		task->context = NULL;
+		fcgi->task = NULL;
+		__ha_barrier_store();
+		task_kill(task);
 
 		fcgi->task = task_new(tid_bit);
 		if (!fcgi->task) {