[GHC] #14492: Tiered memory allocation restricts available memory

[GHC]

#14492: Tiered memory allocation restricts available memory
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        Reporter:  unode             |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Runtime System    |              Version:  8.0.2
      Resolution:                    |             Keywords:  memory ulimit
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Poor/confusing    |  (amd64)
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4215
       Wiki Page:                    |
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Comment (by bgamari):

 Another option, as suggested by Jaffacake on Diff:D4215, would be to probe
 the limit. This test program
 {{{#!c
 #include <stdlib.h>
 #include <stdio.h>
 #include <sys/time.h>
 #include <sys/resource.h>

 void print_limit(const char* name, int resource) {
         struct rlimit lim;
         if (getrlimit(resource, &lim) != 0) {
                 printf("%s: uh oh\n", name);
                 exit(1);
         }
         printf("%s: cur: %d\n", name, lim.rlim_cur);
         printf("%s: max: %d\n", name, lim.rlim_max);
 }

 int main() {
         print_limit("AS", RLIMIT_AS);
         print_limit("DATA", RLIMIT_DATA);
         print_limit("RSS", RLIMIT_RSS);
         print_limit("STACK", RLIMIT_STACK);
         return 0;
 }
 }}}

 reveals that `ulimit -v` affects `RLIMIT_AS`, which can be probed with
 `getrlimit`.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14492#comment:8>
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