From: Rick Hudson <rlh@golang.org>
Date: Tue, 28 Apr 2015 13:07:51 +0000 (-0400)
Subject: runtime: Reduce calls to shouldtriggergc
X-Git-Tag: go1.5beta1~764
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b86e71f5aae4bd2cd2b1010e1c57909c068178cc;p=gostls13.git

runtime: Reduce calls to shouldtriggergc

shouldtriggergc is slightly expensive due to the call overhead
and the use of an atomic. This CL reduces the number of time
one checks if a GC should be done from one at each allocation
to once when a span is allocated. Since shouldtriggergc is an
important abstraction simply hand inlining it, along with its
atomic instruction would lose the abstraction.

Change-Id: Ia3210655b4b3d433f77064a21ecb54e4d9d435f7
Reviewed-on: https://go-review.googlesource.com/9403
Reviewed-by: Austin Clements <austin@google.com>
---

diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 91d69b5a9b..22ad6b581f 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -684,7 +684,7 @@ func mallocgc(size uintptr, typ *_type, flags uint32) unsafe.Pointer {
 		}
 	}
 
-	if shouldtriggergc() {
+	if shouldhelpgc && shouldtriggergc() {
 		startGC(gcBackgroundMode)
 	} else if gcBlackenEnabled != 0 {
 		// Assist garbage collector. We delay this until the