From: Dmitriy Vyukov <dvyukov@google.com>
Date: Wed, 7 Nov 2012 08:48:58 +0000 (+0400)
Subject: runtime/race: lazily allocate shadow memory
X-Git-Tag: go1.1rc2~1942
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=1a19f01a683f8c62b7bd5f843a2e1b7ed6449542;p=gostls13.git

runtime/race: lazily allocate shadow memory
Currently race detector runtime maps shadow memory eagerly at process startup.
It works poorly on Windows, because Windows requires reservation in swap file
(especially problematic if several Go program runs at the same, each consuming GBs
of memory).
With this change race detector maps shadow memory lazily, so Go runtime must notify
about all new heap memory.
It will help with Windows port, but also eliminates scary 16TB virtual mememory
consumption in top output (which sometimes confuses some monitoring scripts).

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6811085
---

diff --git a/src/pkg/runtime/malloc.goc b/src/pkg/runtime/malloc.goc
index f8aa1c949e..a96372451c 100644
--- a/src/pkg/runtime/malloc.goc
+++ b/src/pkg/runtime/malloc.goc
@@ -434,6 +434,8 @@ runtime·MHeap_SysAlloc(MHeap *h, uintptr n)
 		runtime·SysMap(p, n);
 		h->arena_used += n;
 		runtime·MHeap_MapBits(h);
+		if(raceenabled)
+			runtime·racemapshadow(p, n);
 		return p;
 	}
 	
@@ -460,6 +462,8 @@ runtime·MHeap_SysAlloc(MHeap *h, uintptr n)
 		if(h->arena_used > h->arena_end)
 			h->arena_end = h->arena_used;
 		runtime·MHeap_MapBits(h);
+		if(raceenabled)
+			runtime·racemapshadow(p, n);
 	}
 	
 	return p;
diff --git a/src/pkg/runtime/race.c b/src/pkg/runtime/race.c
index ef7eec2b6b..49c7d4eb2c 100644
--- a/src/pkg/runtime/race.c
+++ b/src/pkg/runtime/race.c
@@ -11,6 +11,7 @@
 #include "race.h"
 
 void runtime∕race·Initialize(void);
+void runtime∕race·MapShadow(void *addr, uintptr size);
 void runtime∕race·Finalize(void);
 void runtime∕race·FinalizerGoroutine(int32);
 void runtime∕race·Read(int32 goid, void *addr, void *pc);
@@ -35,6 +36,7 @@ runtime·raceinit(void)
 {
 	m->racecall = true;
 	runtime∕race·Initialize();
+	runtime∕race·MapShadow(noptrdata, enoptrbss - noptrdata);
 	m->racecall = false;
 }
 
@@ -46,6 +48,14 @@ runtime·racefini(void)
 	m->racecall = false;
 }
 
+void
+runtime·racemapshadow(void *addr, uintptr size)
+{
+	m->racecall = true;
+	runtime∕race·MapShadow(addr, size);
+	m->racecall = false;
+}
+
 // Called from instrumented code.
 // If we split stack, getcallerpc() can return runtime·lessstack().
 #pragma textflag 7
diff --git a/src/pkg/runtime/race.h b/src/pkg/runtime/race.h
index eea1f9465e..9ebb9d3738 100644
--- a/src/pkg/runtime/race.h
+++ b/src/pkg/runtime/race.h
@@ -15,6 +15,7 @@ void	runtime·raceinit(void);
 // Finalize race detection subsystem, does not return.
 void	runtime·racefini(void);
 
+void	runtime·racemapshadow(void *addr, uintptr size);
 void	runtime·racemalloc(void *p, uintptr sz, void *pc);
 void	runtime·racefree(void *p);
 void	runtime·racegostart(int32 goid, void *pc);
diff --git a/src/pkg/runtime/race/race.go b/src/pkg/runtime/race/race.go
index f3a7be50c6..fb59ee8338 100644
--- a/src/pkg/runtime/race/race.go
+++ b/src/pkg/runtime/race/race.go
@@ -10,6 +10,7 @@ package race
 /*
 void __tsan_init(void);
 void __tsan_fini(void);
+void __tsan_map_shadow(void *addr, void *size);
 void __tsan_go_start(int pgoid, int chgoid, void *pc);
 void __tsan_go_end(int goid);
 void __tsan_read(int goid, void *addr, void *pc);
@@ -38,6 +39,10 @@ func Finalize() {
 	C.__tsan_fini()
 }
 
+func MapShadow(addr, size uintptr) {
+	C.__tsan_map_shadow(unsafe.Pointer(addr), unsafe.Pointer(size))
+}
+
 func FinalizerGoroutine(goid int32) {
 	C.__tsan_finalizer_goroutine(C.int(goid))
 }
diff --git a/src/pkg/runtime/race/race_darwin_amd64.syso b/src/pkg/runtime/race/race_darwin_amd64.syso
index b291e8e078..b323a71297 100644
Binary files a/src/pkg/runtime/race/race_darwin_amd64.syso and b/src/pkg/runtime/race/race_darwin_amd64.syso differ
diff --git a/src/pkg/runtime/race/race_linux_amd64.syso b/src/pkg/runtime/race/race_linux_amd64.syso
index c8e331f716..ccc42e57ca 100644
Binary files a/src/pkg/runtime/race/race_linux_amd64.syso and b/src/pkg/runtime/race/race_linux_amd64.syso differ
diff --git a/src/pkg/runtime/race0.c b/src/pkg/runtime/race0.c
index b650a14712..82ebba8229 100644
--- a/src/pkg/runtime/race0.c
+++ b/src/pkg/runtime/race0.c
@@ -17,6 +17,14 @@ runtime·racefini(void)
 {
 }
 
+
+void
+runtime·racemapshadow(void *addr, uintptr size)
+{
+	USED(addr);
+	USED(size);
+}
+
 void
 runtime·racewritepc(void *addr, void *pc)
 {