Looing for advice on profiling

Malcolm Wallace Malcolm.Wallace at cs.york.ac.uk
Tue Nov 9 08:42:26 EST 2004

Duncan Coutts <duncan.coutts at worc.ox.ac.uk> writes:

> I'm looking for some advice on profiling and any suggestion on what
> might be going on with this program.

One suggestion might be to serialise (key,value) pairs to file as
they are first encountered, rather than waiting until they are all
inside FiniteMaps.  That would eliminate the time you are currently
spending on lookups.  (A subsequent run would then need to do the
insertion of binary (key,value)s, rather than having them already
ordered, but at least you save the textual parsing cost there.)

> A major problem no doubt is space use. For the large gtk/gtk.h, when I
> run with +RTS -B to get a beep every major garbage collection, the
> serialisation phase beeps continuously while the file grows.
> Occasionally it seems to freeze for 10s of seconds, not dong any garbage
> collection and not doing any file output but using 100% CPU, then it
> carries on outputting and garbage collecting furiously. I don't know how
> to work out what's going on when it does that.

One guess might be generational collection: fast beeps are for the
current generation, pauses are older generations?


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