[GHC] #14193: Add RTS flag to disable 1TB address space allocation

[GHC]

#14193: Add RTS flag to disable 1TB address space allocation
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        Reporter:  nh2               |                Owner:  (none)
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9706, #14192     |  Differential Rev(s):  Phab:D3929
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"1d1b991ee15e0428be16d1bfad7087051e000bdc/ghc" 1d1b991/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="1d1b991ee15e0428be16d1bfad7087051e000bdc"
 rts: Inform kernel that we won't need reserved address space

 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
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14193#comment:9>
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