id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
2192,occasional segmentation faults when using Control.Parallel,ivant,igloo,"The attached program fails quite often with segmentation faults or internal errors (unpredictably, in consecutive runs, without changing the source):
{{{
% time ./parallel +RTS -N2                                   
zsh: segmentation fault (core dumped)  ./parallel +RTS -N2
./parallel +RTS -N2  2.79s user 0.42s system 107% cpu 2.988 total

% time ./parallel +RTS -N2
parallel: internal error: evacuate: strange closure type 65284
    (GHC version 6.8.2 for i386_unknown_linux)
    Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
zsh: abort (core dumped)  ./parallel +RTS -N2
./parallel +RTS -N2  3.60s user 0.51s system 108% cpu 3.781 total

% time ./parallel +RTS -N2
zsh: segmentation fault (core dumped)  ./parallel +RTS -N2
./parallel +RTS -N2  5.09s user 0.46s system 111% cpu 4.982 total

% time ./parallel +RTS -N2
500000
./parallel +RTS -N2  8.34s user 0.14s system 108% cpu 7.796 total
}}}

The program can fail both when it is compiled with and without -O2.
Changing the value of maxSparks makes a difference (with value 2 it is finishing successfully always (or probably more often)).",merge,closed,normal,6.8.3,Runtime System,6.8.2,fixed,par,,Linux,x86,,Unknown,,,,