From 2425a2e32f57a5df3a048a06431089fd83e8cec9 Mon Sep 17 00:00:00 2001
From: Keith Randall <khr@golang.org>
Date: Fri, 18 Jul 2014 13:05:21 +0400
Subject: [PATCH] runtime: fix gctrace=1

updatememstats is called on both the m and g stacks.
Call into flushallmcaches correctly.  flushallmcaches
can only run on the M stack.

This is somewhat temporary.  once ReadMemStats is in
Go we can have all of this code M-only.

LGTM=dvyukov
R=golang-codereviews, dvyukov
CC=golang-codereviews
https://golang.org/cl/116880043
---
 src/pkg/runtime/mgc0.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/pkg/runtime/mgc0.c b/src/pkg/runtime/mgc0.c
index 8b9779da6b..2d478acdc4 100644
--- a/src/pkg/runtime/mgc0.c
+++ b/src/pkg/runtime/mgc0.c
@@ -2172,7 +2172,10 @@ runtime·updatememstats(GCStats *stats)
 	}
 
 	// Flush MCache's to MCentral.
-	runtime·mcall(flushallmcaches_m);
+	if(g == g->m->g0)
+		flushallmcaches();
+	else
+		runtime·mcall(flushallmcaches_m);
 
 	// Aggregate local stats.
 	cachestats();