runtime: darwin/arm64 support
Change-Id: I3b3f80791a1db4c2b7318f81a115972cd2237f03
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/8782
Reviewed-by: David Crawshaw <crawshaw@golang.org>
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 72a10d1..e41c273 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -155,7 +155,10 @@
// See http://golang.org/issue/5402 and http://golang.org/issue/5236.
// On other 64-bit platforms, we limit the arena to 128GB, or 37 bits.
// On 32-bit, we don't bother limiting anything, so we use the full 32-bit address.
- _MHeapMap_TotalBits = (_64bit*goos_windows)*35 + (_64bit*(1-goos_windows))*37 + (1-_64bit)*32
+ // On Darwin/arm64, we cannot reserve more than ~5GB of virtual memory,
+ // but as most devices have less than 4GB of physical memory anyway, we
+ // try to be conservative here, and only ask for a 2GB heap.
+ _MHeapMap_TotalBits = (_64bit*goos_windows)*35 + (_64bit*(1-goos_windows)*(1-goos_darwin*goarch_arm64))*37 + goos_darwin*goarch_arm64*31 + (1-_64bit)*32
_MHeapMap_Bits = _MHeapMap_TotalBits - _PageShift
_MaxMem = uintptr(1<<_MHeapMap_TotalBits - 1)
@@ -257,14 +260,18 @@
// However, on arm64, we ignore all this advice above and slam the
// allocation at 0x40 << 32 because when using 4k pages with 3-level
// translation buffers, the user address space is limited to 39 bits
+ // On darwin/arm64, the address space is even smaller.
arenaSize := round(_MaxMem, _PageSize)
bitmapSize = arenaSize / (ptrSize * 8 / 4)
spansSize = arenaSize / _PageSize * ptrSize
spansSize = round(spansSize, _PageSize)
for i := 0; i <= 0x7f; i++ {
- if GOARCH == "arm64" {
+ switch {
+ case GOARCH == "arm64" && GOOS == "darwin":
+ p = uintptr(i)<<40 | uintptrMask&(0x0013<<28)
+ case GOARCH == "arm64":
p = uintptr(i)<<40 | uintptrMask&(0x0040<<32)
- } else {
+ default:
p = uintptr(i)<<40 | uintptrMask&(0x00c0<<32)
}
pSize = bitmapSize + spansSize + arenaSize + _PageSize
