runtime: make allp a static array

It is anyway, just an allocated one.
Giving it a sized type makes Go access nicer.

LGTM=iant
R=dvyukov, iant
CC=golang-codereviews
https://golang.org/cl/139960043

diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index d91a829c15d0ed3b88feab646b62053a15e22bc5..666adfb7db777ae226347bc48601d3364d38ecbf 100644 (file)
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -62,10 +62,6 @@ struct Sched {
 
 enum
 {
-       // The max value of GOMAXPROCS.
-       // There are no fundamental restrictions on the value.
-       MaxGomaxprocs = 1<<8,
-
        // Number of goroutine ids to grab from runtime·sched.goidgen to local per-P cache at once.
        // 16 seems to provide enough amortization, but other than that it's mostly arbitrary number.
        GoidCacheBatch = 16,
@@ -80,6 +76,7 @@ G     runtime·g0;    // idle goroutine for m0
 G*     runtime·lastg;
 M*     runtime·allm;
 M*     runtime·extram;
+P*     runtime·allp[MaxGomaxprocs+1];
 int8*  runtime·goos;
 int32  runtime·ncpu;
 static int32   newprocs;
@@ -180,7 +177,6 @@ runtime·schedinit(void)
                        n = MaxGomaxprocs;
                procs = n;
        }
-       runtime·allp = runtime·mallocgc((MaxGomaxprocs+1)*sizeof(runtime·allp[0]), nil, 0);
        procresize(procs);
 
        runtime·copystack = runtime·precisestack;

diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index 27b945e979d3eb56d7db3cdb70d263c23637977b..3f03a4da0668c9eb3364f2d63b4585467b44e624 100644 (file)
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -422,6 +422,12 @@ struct P
        byte    pad[64];
 };
 
+enum {
+       // The max value of GOMAXPROCS.
+       // There are no fundamental restrictions on the value.
+       MaxGomaxprocs = 1<<8,
+};
+
 // The m->locked word holds two pieces of state counting active calls to LockOSThread/lockOSThread.
 // The low bit (LockExternal) is a boolean reporting whether any LockOSThread call is active.
 // External locks are not recursive; a second lock is silently ignored.
@@ -768,7 +774,7 @@ extern      G**     runtime·allg;
 extern uintptr runtime·allglen;
 extern G*      runtime·lastg;
 extern M*      runtime·allm;
-extern P**     runtime·allp;
+extern P*      runtime·allp[MaxGomaxprocs+1];
 extern int32   runtime·gomaxprocs;
 extern uint32  runtime·needextram;
 extern uint32  runtime·panicking;