diff options
Diffstat (limited to 'libgo/runtime/mgc0.c')
| -rw-r--r-- | libgo/runtime/mgc0.c | 63 |
1 files changed, 40 insertions, 23 deletions
diff --git a/libgo/runtime/mgc0.c b/libgo/runtime/mgc0.c index 73c399df239..7e68535ebfd 100644 --- a/libgo/runtime/mgc0.c +++ b/libgo/runtime/mgc0.c @@ -4,6 +4,8 @@ // Garbage collector. +#include <unistd.h> + #include "runtime.h" #include "arch.h" #include "malloc.h" @@ -61,6 +63,21 @@ enum { #define bitMask (bitBlockBoundary | bitAllocated | bitMarked | bitSpecial) +// Holding worldsema grants an M the right to try to stop the world. +// The procedure is: +// +// runtime_semacquire(&runtime_worldsema); +// m->gcing = 1; +// runtime_stoptheworld(); +// +// ... do stuff ... +// +// m->gcing = 0; +// runtime_semrelease(&runtime_worldsema); +// runtime_starttheworld(); +// +uint32 runtime_worldsema = 1; + // TODO: Make these per-M. static uint64 nhandoff; @@ -92,7 +109,6 @@ struct FinBlock Finalizer fin[1]; }; - static G *fing; static FinBlock *finq; // list of finalizers that are to be executed static FinBlock *finc; // cache of free blocks @@ -640,14 +656,6 @@ markfin(void *v) scanblock(v, size); } -struct root_list { - struct root_list *next; - struct root { - void *decl; - size_t size; - } roots[]; -}; - static struct root_list* roots; void @@ -778,9 +786,11 @@ sweep(void) byte *p; MCache *c; byte *arena_start; + int64 now; m = runtime_m(); arena_start = runtime_mheap.arena_start; + now = runtime_nanotime(); for(;;) { s = work.spans; @@ -789,6 +799,11 @@ sweep(void) if(!runtime_casp(&work.spans, s, s->allnext)) continue; + // Stamp newly unused spans. The scavenger will use that + // info to potentially give back some pages to the OS. + if(s->state == MSpanFree && s->unusedsince == 0) + s->unusedsince = now; + if(s->state != MSpanInUse) continue; @@ -875,11 +890,6 @@ runtime_gchelper(void) runtime_notewakeup(&work.alldone); } -// Semaphore, not Lock, so that the goroutine -// reschedules when there is contention rather -// than spinning. -static uint32 gcsema = 1; - // Initialized from $GOGC. GOGC=off means no gc. // // Next gc is after we've allocated an extra amount of @@ -910,7 +920,7 @@ cachestats(void) uint64 stacks_sys; stacks_inuse = 0; - stacks_sys = 0; + stacks_sys = runtime_stacks_sys; for(m=runtime_allm; m; m=m->alllink) { runtime_purgecachedstats(m); // stacks_inuse += m->stackalloc->inuse; @@ -968,9 +978,9 @@ runtime_gc(int32 force) if(gcpercent < 0) return; - runtime_semacquire(&gcsema); + runtime_semacquire(&runtime_worldsema); if(!force && mstats.heap_alloc < mstats.next_gc) { - runtime_semrelease(&gcsema); + runtime_semrelease(&runtime_worldsema); return; } @@ -1012,7 +1022,7 @@ runtime_gc(int32 force) stealcache(); cachestats(); - mstats.next_gc = mstats.heap_alloc+mstats.heap_alloc*gcpercent/100; + mstats.next_gc = mstats.heap_alloc+(mstats.heap_alloc-runtime_stacks_sys)*gcpercent/100; m->gcing = 0; m->locks++; // disable gc during the mallocs in newproc @@ -1032,6 +1042,7 @@ runtime_gc(int32 force) obj1 = mstats.nmalloc - mstats.nfree; t3 = runtime_nanotime(); + mstats.last_gc = t3; mstats.pause_ns[mstats.numgc%nelem(mstats.pause_ns)] = t3 - t0; mstats.pause_total_ns += t3 - t0; mstats.numgc++; @@ -1045,8 +1056,9 @@ runtime_gc(int32 force) (unsigned long long) mstats.nmalloc, (unsigned long long)mstats.nfree, (unsigned long long) nhandoff); } - - runtime_semrelease(&gcsema); + + runtime_MProf_GC(); + runtime_semrelease(&runtime_worldsema); // If we could have used another helper proc, start one now, // in the hope that it will be available next time. @@ -1073,18 +1085,18 @@ runtime_ReadMemStats(MStats *stats) { M *m; - // Have to acquire gcsema to stop the world, + // Have to acquire worldsema to stop the world, // because stoptheworld can only be used by // one goroutine at a time, and there might be // a pending garbage collection already calling it. - runtime_semacquire(&gcsema); + runtime_semacquire(&runtime_worldsema); m = runtime_m(); m->gcing = 1; runtime_stoptheworld(); cachestats(); *stats = mstats; m->gcing = 0; - runtime_semrelease(&gcsema); + runtime_semrelease(&runtime_worldsema); runtime_starttheworld(false); } @@ -1319,6 +1331,8 @@ runtime_setblockspecial(void *v, bool s) void runtime_MHeap_MapBits(MHeap *h) { + size_t page_size; + // Caller has added extra mappings to the arena. // Add extra mappings of bitmap words as needed. // We allocate extra bitmap pieces in chunks of bitmapChunk. @@ -1332,6 +1346,9 @@ runtime_MHeap_MapBits(MHeap *h) if(h->bitmap_mapped >= n) return; + page_size = getpagesize(); + n = (n+page_size-1) & ~(page_size-1); + runtime_SysMap(h->arena_start - n, n - h->bitmap_mapped); h->bitmap_mapped = n; } |