From 1cc8c87dc12e6d1722acc7a3749e63848d8ea26a Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Wed, 9 Feb 2011 15:08:30 -0500 Subject: [PATCH] runtime: fix memory allocation on 386 BSD and Darwin require an extra page between end and the first mapping, and Windows has various memory in the way too. Fixes #1464. R=r, r2 CC=golang-dev https://golang.org/cl/4167041 --- src/pkg/runtime/malloc.goc | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/pkg/runtime/malloc.goc b/src/pkg/runtime/malloc.goc index 8899b01195..18652d71a6 100644 --- a/src/pkg/runtime/malloc.goc +++ b/src/pkg/runtime/malloc.goc @@ -286,10 +286,16 @@ runtime·mallocinit(void) // of address space, which is probably too much in a 32-bit world. bitmap_size = MaxArena32 / (sizeof(void*)*8/4); arena_size = 512<<20; - - p = (void*)(((uintptr)end + 64*1024 - 1) & ~(64*1024-1)); - if(runtime·SysReserve(p, bitmap_size + arena_size) != p) - runtime·throw("runtime: cannot reserve memory bitmap virtual address space"); + + // SysReserve treats the address we ask for, end, as a hint, + // not as an absolute requirement. If we ask for the end + // of the data segment but the operating system requires + // a little more space before we can start allocating, it will + // give out a slightly higher pointer. That's fine. + // Run with what we get back. + p = runtime·SysReserve(end, bitmap_size + arena_size); + if(p == nil) + runtime·throw("runtime: cannot reserve arena virtual address space"); } runtime·mheap.bitmap = p; runtime·mheap.arena_start = p + bitmap_size; -- 2.50.0