29 Nov
2008
29 Nov
'08
2:42 p.m.
yrn001:
Hi,
Since I upgraded from ghc 6.8.3 to 6.10.1, I noticed that my programs do not run multi-threaded anymore. I tried simplifying my code, till I just took one of the par/pseq demo's to verify if it wasn't my fault.
This sounds like the change to the scheduler where only 1 spark won't trigger the other core to wake up. See this mail from Simon Marlow, http://www.haskell.org/pipermail/haskell-cafe/2008-November/050974.html "I'll make sure it gets fixed for 6.10.2. If you have more sparks then you shouldn't see this problem. Also, GHC HEAD is quite a lot better with parallel programs than 6.10.1, I'll try to get around to posting some figures sometime."