From: Austin Clements <austin@google.com>
Date: Wed, 8 Jul 2015 21:18:33 +0000 (-0700)
Subject: runtime: make sysmon-triggered GC concurrent
X-Git-Tag: go1.5beta2~111
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=4b2774f5ea4f6f0beb75259f65e60585b6dbfd56;p=gostls13.git

runtime: make sysmon-triggered GC concurrent

sysmon triggers a GC if there has been no GC for two minutes.
Currently, this is a STW GC. There is no reason for this to be STW, so
make it concurrent.

Fixes #10261.

Change-Id: I92f3ac37272d5c2a31480ff1fa897ebad08775a9
Reviewed-on: https://go-review.googlesource.com/11955
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
---

diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 805b96e627..1a4c6c109f 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -154,7 +154,7 @@ func forcegchelper() {
 		if debug.gctrace > 0 {
 			println("GC forced")
 		}
-		startGC(gcForceMode)
+		startGC(gcBackgroundMode)
 	}
 }
 
diff --git a/src/runtime/proc1.go b/src/runtime/proc1.go
index 6a163c62a0..a048ded94c 100644
--- a/src/runtime/proc1.go
+++ b/src/runtime/proc1.go
@@ -3004,7 +3004,7 @@ func sysmon() {
 		}
 		// check if we need to force a GC
 		lastgc := int64(atomicload64(&memstats.last_gc))
-		if lastgc != 0 && unixnow-lastgc > forcegcperiod && atomicload(&forcegc.idle) != 0 {
+		if lastgc != 0 && unixnow-lastgc > forcegcperiod && atomicload(&forcegc.idle) != 0 && atomicloaduint(&bggc.working) == 0 {
 			lock(&forcegc.lock)
 			forcegc.idle = 0
 			forcegc.g.schedlink = 0