The Haskell Cafe isn't the right forum for this. Please file a bug report here: http://hackage.haskell.org/trac/ghc/newticket?type=bug -- Don manlio_perillo:

Hi.

In a program I have experienced a segmentation fault; not only that but also:

* tpp.c:63: __pthread_tpp_change_priority: Assertion `new_prio == -1 || (new_prio >= __sched_fifo_min_prio && new_prio <= __sched_fifo_max_prio)' failed.

* internal error: removeThreadFromQueue: not found (GHC version 6.8.2 for i386_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug

I have managed to write a program that reproduces the problem: http://hpaste.org/fastcgi/hpaste.fcgi/view?id=3714

Compile with: $ghc --make -threaded -O2 main.hs Execute with: $./main +RTS -A128M -s -c -N4 -RTS 5000000 500

This should produce a segmentation fault (or one of the previous errors).

I strongly suspect that the cause is an uncaught stack overflow.

Executing the code with only 1 threads, there are no more problems. Increasing the thread stack size (-k1M), there are no more problems.

If the problem is really an uncaught stack overflow, I'm rather sure that a more simple test can be written, to reproduce the problem.

I'm on Linux Debian Etch i386; GHC 6.8.2.

Some notes about the program: - when no segmentation fault occurs, the program requires about 1 GB of memory - there is no real parallelization, only 1 CPU is used - the mapReduce implementation is taken from Real World Haskell - the code is adapted from the code I'm using in a project

Thanks Manlio Perillo _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe