[GHC] #12865: POSIX osDecommitMemory has nasty compatibility problems

[GHC]

#12865: POSIX osDecommitMemory has nasty compatibility problems
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  high              |            Milestone:  8.2.1
       Component:  Runtime System    |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2780
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"6576bf83cdf4eac05eb88a24aa934a736c91e3da/ghc"
 6576bf83/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="6576bf83cdf4eac05eb88a24aa934a736c91e3da"
 rts: Ensure we always give MADV_DONTNEED a chance in osDecommitMemory

 As described in #12865, newer Linux kernels support both MADV_FREE and
 MADV_DONTNEED. Previously a runtime would fail to try MADV_DONTNEED if
 MADV_FREE failed (e.g. since the kernel which the image is running on
 doesn't support the latter). Now we try MADV_DONTNEED if MADV_FREE
 failed to ensure that binaries compiled on a kernel supporting MADV_FREE
 don't fail on decommit.

 Test Plan: Validate

 Reviewers: austin, erikd, simonmar

 Reviewed By: simonmar

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D2780

 GHC Trac Issues: #12865
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12865#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler