[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
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        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:                    |
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Comment (by bgamari):

 Ahh, I see, `advise` isn't a bitmap; I've confirmed that this,
 {{{#!c
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
 #include <assert.h>
 #include <sys/mman.h>

 int main() {
         const int len = 1024*1024*1024;
         void *p = mmap(NULL, len, PROT_NONE,
 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0);
         if (p == MAP_FAILED) {
                 printf("uh oh: mmap failed: %s\n", strerror(errno));
         }
         int res = madvise(p, len, MADV_DONTDUMP);
         if (res != 0) {
                 printf("uh oh: madvise failed: %s\n", strerror(errno));
         }
         assert(0); // use generate-core-file in gdb when this is hit
         return 0;
 }
 }}}
 produces a small (510kB) core dump in `gdb`.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14192#comment:15>
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