Re: [Haskell-cafe] SMP parallelism increasing GC time dramatically

I'm trying to narrow it down so that I can submit a meaningful bug report, and it seems to be something to do with switching off parallel GC using -qg, whilst also passing -Nx. Are there any known issues with this that people are aware of? At the moment I am using the latest haskell platform release on arch. I'd like to give 7.2 a try in case that fixes it, but I'm using rather a lot of libraries (hmatrix, fclabels, random fu) and I don't know how to install them for multiple ghc versions On Wed, Oct 5, 2011 at 10:43 PM, Johan Tibell wrote:

On Wed, Oct 5, 2011 at 2:37 PM, Tom Thorne wrote:

...

The only problem is that now I am getting random occasional segmentation faults that I was not been getting before, and once got a message saying: Main: schedule: re-entered unsafely Perhaps a 'foreign import unsafe' should be 'safe'? I think this may be something to do with creating a lot of sparks though, since this occurs whether I have the parallel GC on or not.

Unless you (or some library you're using) is doing what the error message says then you should file a GHC bug here:

http://hackage.haskell.org/trac/ghc/

-- Johan