tree a55ee712559dc024eba3cf95d6ccdab9ff3d40e6
parent d6899463029d8ab0d73c992ccf6639f095435b84
author Michael Anthony Knyszek <mknyszek@google.com> 1544565784 +0000
committer Michael Knyszek <mknyszek@google.com> 1545167105 +0000

runtime: call mmap with MAP_FIXED on BSDs in race mode

This change makes it so that reserving more of the address space for the
heap calls mmap with MAP_FIXED in race mode. Race mode requires certain
guarantees on where the heap is located in the address space, and on
Darwin 10.10 it appears that the kernel may end up ignoring the hint
quite often (#26475). Using MAP_FIXED is relatively OK in race mode
because nothing else should be mapped in the memory region provided by
the initial hints.

Fixes #26475.

Change-Id: Id7ac1534ee74f6de491bc04441f27dbda09f0285
Reviewed-on: https://go-review.googlesource.com/c/153897
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>