runtime: fix GC bitmap corruption
The corruption can occur when GOMAXPROCS
is changed from >1 to 1, since GOMAXPROCS=1
does not imply there is only 1 goroutine running,
other goroutines can still be not parked after
the change.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4873050
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index 00be565..3c503e4 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -383,6 +383,7 @@
G* runtime·allg;
M* runtime·allm;
extern int32 runtime·gomaxprocs;
+extern bool runtime·singleproc;
extern uint32 runtime·panicking;
extern int32 runtime·gcwaiting; // gc is waiting to run
int8* runtime·goos;
