2010/9/21 Simon Marlow <[email protected]>: > On 19/09/2010 13:11, Stefan Wehr wrote: >> >> Hi all, >> >> I'm profiling a Haskell program and now getting that the program >> spents 56% of its individual time in the cost centre MAIN (note the >> capital letters). >> >> I searched the documentation for this cost centre, with no success. In >> all profiling results so far, the individual time spent in MAIN was >> always 0%. > > The profiler constructs a tree of cost centres representing the lexical call > structure of your program. The root of this tree is the special cost centre > "MAIN", which will collect any costs that are not otherwise attributed to > any other cost centre. > > Usually if you get lots of costs attributed to "MAIN", then you don't have > any cost centres; you should either compile with -auto-all, or add explicit > cost centres yourself with {-# SCC "..." #-}.
I compiled the program with -auto-all and -caf-all, but also with -threaded. The -threaded flag makes the difference, if I remove this flag, cost centre MAIN is back at 0%. The program in question uses STM and quite a lot of threads. Maybe transaction and synchronization costs are summarized under MAIN?! Any comments? Thanks, Stefan _______________________________________________ Glasgow-haskell-users mailing list [email protected] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
