From 613388315e29d4e906805e602602500ca1e7e334 Mon Sep 17 00:00:00 2001
From: Cholerae Hu <choleraehyq@gmail.com>
Date: Mon, 11 May 2020 11:18:57 +0800
Subject: [PATCH] runtime: reduce critical path in injectglist

Change-Id: Ia3fb30ac9add39c803f11f69d967c6604fdeacf8
Reviewed-on: https://go-review.googlesource.com/c/go/+/233217
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
---
 src/runtime/proc.go | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 9a358cd529..5e38b3194c 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -2575,15 +2575,20 @@ func injectglist(glist *gList) {
 		return
 	}
 
-	lock(&sched.lock)
-	npidle := int(sched.npidle)
+	npidle := int(atomic.Load(&sched.npidle))
+	var globq gQueue
 	var n int
 	for n = 0; n < npidle && !q.empty(); n++ {
-		globrunqput(q.pop())
+		g := q.pop()
+		globq.pushBack(g)
+	}
+	if n > 0 {
+		lock(&sched.lock)
+		globrunqputbatch(&globq, int32(n))
+		unlock(&sched.lock)
+		startIdle(n)
+		qsize -= n
 	}
-	unlock(&sched.lock)
-	startIdle(n)
-	qsize -= n
 
 	if !q.empty() {
 		runqputbatch(pp, &q, qsize)
-- 
2.50.0