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| author | Dmitriy Vyukov <dvyukov@google.com> | 2014-08-24 12:04:51 +0400 |
|---|---|---|
| committer | Dmitriy Vyukov <dvyukov@google.com> | 2014-08-24 12:04:51 +0400 |
| commit | b91223edd19590b4ac79ae14b66b8d5a80825e36 (patch) | |
| tree | a04c5c94dfa6788c40beb2217512c2db5dc76df0 /src/pkg/runtime | |
| parent | 651d0cf204da51eddec88c32c039d750ef7edbbd (diff) | |
| download | go-b91223edd19590b4ac79ae14b66b8d5a80825e36.tar.xz | |
runtime: cache unrolled GC bitmask
Cache unrolled GC bitmask for types up to 64/32K on 64/32-bit systems,
this corresponds to up to 4K cached bitmask.
Perf builders say that 2% of time is spent in unrollgcproginplace_m/unrollgcprog1
on http benchmark:
http://goperfd.appspot.com/log/f42045f45bf61a0da53b724a7c8567824a0ad6c9
LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews, khr, rlh
https://golang.org/cl/122680043
Diffstat (limited to 'src/pkg/runtime')
| -rw-r--r-- | src/pkg/runtime/malloc.go | 2 | ||||
| -rw-r--r-- | src/pkg/runtime/mgc0.h | 3 |
2 files changed, 3 insertions, 2 deletions
diff --git a/src/pkg/runtime/malloc.go b/src/pkg/runtime/malloc.go index 578fbd1c2d..ffe571a18a 100644 --- a/src/pkg/runtime/malloc.go +++ b/src/pkg/runtime/malloc.go @@ -28,7 +28,7 @@ const ( bitsMask = 1<<bitsPerPointer - 1 pointersPerByte = 8 / bitsPerPointer bitPtrMask = bitsMask << 2 - maxGCMask = 0 // disabled because wastes several bytes of memory + maxGCMask = 64 bitsDead = 0 bitsPointer = 2 diff --git a/src/pkg/runtime/mgc0.h b/src/pkg/runtime/mgc0.h index 7449398b9f..a7292effd3 100644 --- a/src/pkg/runtime/mgc0.h +++ b/src/pkg/runtime/mgc0.h @@ -55,7 +55,8 @@ enum { BitsIface = 2, BitsEface = 3, - MaxGCMask = 0, // disabled because wastes several bytes of memory + // 64 bytes cover objects of size 1024/512 on 64/32 bits, respectively. + MaxGCMask = 64, }; // Bits in per-word bitmap. |