[GHC] #14192: Change to 1TB VIRT allocation makes it impossible to core-dump Haskell programs

[GHC]

#14192: Change to 1TB VIRT allocation makes it impossible to core-dump Haskell
programs
-------------------------------------+-------------------------------------
        Reporter:  nh2               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Runtime System    |              Version:  8.0.2
      Resolution:                    |             Keywords:  gdb,
                                     |  debugging
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9706             |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

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/14192#comment:17>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler