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Avoid unnecessary operation in PageAllocator.

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There's no need to call `alignForward` before `VirtualAlloc`.
From [MSDN](https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-virtualalloc):
```
If the lpAddress parameter is NULL, this value is rounded up to the next page boundary
```
This commit is contained in:
Lucas Santos 2024-05-09 21:39:11 -03:00 committed by Veikka Tuominen
parent fe1b397606
commit f71f27bcb0
1 changed files with 6 additions and 2 deletions
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8
lib/std/heap/PageAllocator.zig
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@ -19,18 +19,22 @@ fn alloc(_: *anyopaque, n: usize, log2_align: u8, ra: usize) ?[*]u8 {
_ = log2_align; _ = log2_align;
assert(n > 0); assert(n > 0);
if (n > maxInt(usize) - (mem.page_size - 1)) return null; if (n > maxInt(usize) - (mem.page_size - 1)) return null;
const aligned_len = mem.alignForward(usize, n, mem.page_size);
if (native_os == .windows) { if (native_os == .windows) {
const addr = windows.VirtualAlloc( const addr = windows.VirtualAlloc(
null, null,
aligned_len,
// VirtualAlloc will round the length to a multiple of page size.
// VirtualAlloc docs: If the lpAddress parameter is NULL, this value is rounded up to the next page boundary
n,
windows.MEM_COMMIT | windows.MEM_RESERVE, windows.MEM_COMMIT | windows.MEM_RESERVE,
windows.PAGE_READWRITE, windows.PAGE_READWRITE,
) catch return null; ) catch return null;
return @ptrCast(addr); return @ptrCast(addr);
} }
const aligned_len = mem.alignForward(usize, n, mem.page_size);
const hint = @atomicLoad(@TypeOf(std.heap.next_mmap_addr_hint), &std.heap.next_mmap_addr_hint, .unordered); const hint = @atomicLoad(@TypeOf(std.heap.next_mmap_addr_hint), &std.heap.next_mmap_addr_hint, .unordered);
const slice = posix.mmap( const slice = posix.mmap(
hint, hint,