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| author | Dmitriy Vyukov <dvyukov@google.com> | 2014-01-21 10:53:51 +0400 |
|---|---|---|
| committer | Dmitriy Vyukov <dvyukov@google.com> | 2014-01-21 10:53:51 +0400 |
| commit | d5a36cd6bb14a3bf00c58779848beeaeb87ade7d (patch) | |
| tree | a89de67c351b5168e5708b3e823d3286d97444ce | |
| parent | b039abfc3ec93debe732bb4824bebd098ab7a62a (diff) | |
| download | go-d5a36cd6bb14a3bf00c58779848beeaeb87ade7d.tar.xz | |
runtime: zero 2-word memory blocks in-place
Currently for 2-word blocks we set the flag to clear the flag. Makes no sense.
In particular on 32-bits we call memclr always.
R=golang-codereviews, dave, iant
CC=golang-codereviews, khr, rsc
https://golang.org/cl/41170044
| -rw-r--r-- | src/pkg/runtime/malloc.goc | 6 | ||||
| -rw-r--r-- | src/pkg/runtime/mgc0.c | 6 |
2 files changed, 8 insertions, 4 deletions
diff --git a/src/pkg/runtime/malloc.goc b/src/pkg/runtime/malloc.goc index f83e498293..739c61e4f4 100644 --- a/src/pkg/runtime/malloc.goc +++ b/src/pkg/runtime/malloc.goc @@ -75,7 +75,7 @@ runtime·mallocgc(uintptr size, uintptr typ, uint32 flag) if(!(flag & FlagNoZero)) { v->next = nil; // block is zeroed iff second word is zero ... - if(size > sizeof(uintptr) && ((uintptr*)v)[1] != 0) + if(size > 2*sizeof(uintptr) && ((uintptr*)v)[1] != 0) runtime·memclr((byte*)v, size); } c->local_cachealloc += size; @@ -205,8 +205,10 @@ runtime·free(void *v) c->local_largefree += size; } else { // Small object. - if(size > sizeof(uintptr)) + if(size > 2*sizeof(uintptr)) ((uintptr*)v)[1] = (uintptr)0xfeedfeedfeedfeedll; // mark as "needs to be zeroed" + else if(size > sizeof(uintptr)) + ((uintptr*)v)[1] = 0; // Must mark v freed before calling MCache_Free: // it might coalesce v and other blocks into a bigger span // and change the bitmap further. diff --git a/src/pkg/runtime/mgc0.c b/src/pkg/runtime/mgc0.c index 393de7a836..6a1d625a75 100644 --- a/src/pkg/runtime/mgc0.c +++ b/src/pkg/runtime/mgc0.c @@ -1867,9 +1867,11 @@ sweepspan(ParFor *desc, uint32 idx) *(byte*)type_data = 0; break; } - if(size > sizeof(uintptr)) + if(size > 2*sizeof(uintptr)) ((uintptr*)p)[1] = (uintptr)0xdeaddeaddeaddeadll; // mark as "needs to be zeroed" - + else if(size > sizeof(uintptr)) + ((uintptr*)p)[1] = 0; + end->next = (MLink*)p; end = (MLink*)p; nfree++; |