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| author | Cherry Mui <cherryyz@google.com> | 2022-11-16 17:32:08 -0500 |
|---|---|---|
| committer | Cherry Mui <cherryyz@google.com> | 2023-10-02 20:39:21 +0000 |
| commit | 340a4f55c4afac5b74c8df8365decb0c0237d710 (patch) | |
| tree | 6c323e9e445ec5693c9c58e102dbe677e2735c6a /src/runtime/mbitmap.go | |
| parent | 32b6d2d9a849a0f0120e9139b403831669373b79 (diff) | |
| download | go-340a4f55c4afac5b74c8df8365decb0c0237d710.tar.xz | |
runtime: use smaller fields for mspan.freeindex and nelems
mspan.freeindex and nelems can fit into uint16 for all possible
values. Use uint16 instead of uintptr.
Change-Id: Ifce20751e81d5022be1f6b5cbb5fbe4fd1728b1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/451359
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Diffstat (limited to 'src/runtime/mbitmap.go')
| -rw-r--r-- | src/runtime/mbitmap.go | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/runtime/mbitmap.go b/src/runtime/mbitmap.go index 4ba25901d4..20323ff82d 100644 --- a/src/runtime/mbitmap.go +++ b/src/runtime/mbitmap.go @@ -117,8 +117,8 @@ func (s *mspan) allocBitsForIndex(allocBitIndex uintptr) markBits { // and negates them so that ctz (count trailing zeros) instructions // can be used. It then places these 8 bytes into the cached 64 bit // s.allocCache. -func (s *mspan) refillAllocCache(whichByte uintptr) { - bytes := (*[8]uint8)(unsafe.Pointer(s.allocBits.bytep(whichByte))) +func (s *mspan) refillAllocCache(whichByte uint16) { + bytes := (*[8]uint8)(unsafe.Pointer(s.allocBits.bytep(uintptr(whichByte)))) aCache := uint64(0) aCache |= uint64(bytes[0]) aCache |= uint64(bytes[1]) << (1 * 8) @@ -135,7 +135,7 @@ func (s *mspan) refillAllocCache(whichByte uintptr) { // or after s.freeindex. // There are hardware instructions that can be used to make this // faster if profiling warrants it. -func (s *mspan) nextFreeIndex() uintptr { +func (s *mspan) nextFreeIndex() uint16 { sfreeindex := s.freeindex snelems := s.nelems if sfreeindex == snelems { @@ -163,7 +163,7 @@ func (s *mspan) nextFreeIndex() uintptr { // nothing available in cached bits // grab the next 8 bytes and try again. } - result := sfreeindex + uintptr(bitIndex) + result := sfreeindex + uint16(bitIndex) if result >= snelems { s.freeindex = snelems return snelems @@ -191,7 +191,7 @@ func (s *mspan) nextFreeIndex() uintptr { // been no preemption points since ensuring this (which could allow a // GC transition, which would allow the state to change). func (s *mspan) isFree(index uintptr) bool { - if index < s.freeIndexForScan { + if index < uintptr(s.freeIndexForScan) { return false } bytep, mask := s.allocBits.bitp(index) @@ -751,7 +751,7 @@ func (s *mspan) initHeapBits(forceClear bool) { // scanning the allocation bitmap. func (s *mspan) countAlloc() int { count := 0 - bytes := divRoundUp(s.nelems, 8) + bytes := divRoundUp(uintptr(s.nelems), 8) // Iterate over each 8-byte chunk and count allocations // with an intrinsic. Note that newMarkBits guarantees that // gcmarkBits will be 8-byte aligned, so we don't have to |