runtime: print scavenger details when forced with debug.FreeOSMemory

Fixes #5900.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12669043

diff --git a/src/pkg/runtime/mheap.c b/src/pkg/runtime/mheap.c
index 53aa7143361d5d51237f5ad93255c50d8d90ca4b..c03b13bdfd8cd8fe2aadc2299045f0089e60e63a 100644 (file)
--- a/src/pkg/runtime/mheap.c
+++ b/src/pkg/runtime/mheap.c
@@ -412,8 +412,8 @@ scavengelist(MSpan *list, uint64 now, uint64 limit)
        return sumreleased;
 }
 
-static uintptr
-scavenge(uint64 now, uint64 limit)
+static void
+scavenge(int32 k, uint64 now, uint64 limit)
 {
        uint32 i;
        uintptr sumreleased;
@@ -424,7 +424,14 @@ scavenge(uint64 now, uint64 limit)
        for(i=0; i < nelem(h->free); i++)
                sumreleased += scavengelist(&h->free[i], now, limit);
        sumreleased += scavengelist(&h->large, now, limit);
-       return sumreleased;
+
+       if(runtime·debug.gctrace > 0) {
+               if(sumreleased > 0)
+                       runtime·printf("scvg%d: %D MB released\n", k, (uint64)sumreleased>>20);
+               runtime·printf("scvg%d: inuse: %D, idle: %D, sys: %D, released: %D, consumed: %D (MB)\n",
+                       k, mstats.heap_inuse>>20, mstats.heap_idle>>20, mstats.heap_sys>>20,
+                       mstats.heap_released>>20, (mstats.heap_sys - mstats.heap_released)>>20);
+       }
 }
 
 static FuncVal forcegchelperv = {(void(*)(void))forcegchelper};
@@ -437,8 +444,7 @@ runtime·MHeap_Scavenger(void)
 {
        MHeap *h;
        uint64 tick, now, forcegc, limit;
-       uint32 k;
-       uintptr sumreleased;
+       int32 k;
        Note note, *notep;
 
        g->issystem = true;
@@ -476,16 +482,8 @@ runtime·MHeap_Scavenger(void)
                        runtime·lock(h);
                        now = runtime·nanotime();
                }
-               sumreleased = scavenge(now, limit);
+               scavenge(k, now, limit);
                runtime·unlock(h);
-
-               if(runtime·debug.gctrace > 0) {
-                       if(sumreleased > 0)
-                               runtime·printf("scvg%d: %p MB released\n", k, sumreleased>>20);
-                       runtime·printf("scvg%d: inuse: %D, idle: %D, sys: %D, released: %D, consumed: %D (MB)\n",
-                               k, mstats.heap_inuse>>20, mstats.heap_idle>>20, mstats.heap_sys>>20,
-                               mstats.heap_released>>20, (mstats.heap_sys - mstats.heap_released)>>20);
-               }
        }
 }
 
@@ -494,7 +492,7 @@ runtime∕debug·freeOSMemory(void)
 {
        runtime·gc(1);
        runtime·lock(&runtime·mheap);
-       scavenge(~(uintptr)0, 0);
+       scavenge(-1, ~(uintptr)0, 0);
        runtime·unlock(&runtime·mheap);
 }