Ben Gamari authored Sep 26, 2017 and Ben Gamari committed Sep 26, 2017

Trac #14192 points out that currently GHC's two-step allocator results
in extremely large coredumps. It seems like WebKit may have encountered
similar issues and their apparent solution uses madvise(MADV_DONTNEED)
while reserving address space to inform the kernel that the address
space we just requested needs no backing. Perhaps this is used by the
core dump logic to trim out uncommitted pages.

Test Plan: Validate, try core-dumping a compiled executable

Reviewers: austin, erikd, simonmar

Reviewed By: simonmar

Subscribers: rwbarton, thomie

GHC Trac Issues: #14192, #14193

Differential Revision: https://phabricator.haskell.org/D3929