POLL: GC options

Simon Marlow simonmar@microsoft.com
Mon, 6 Aug 2001 12:22:07 +0100


> On Mon, 6 Aug 2001, Simon Marlow wrote:
>=20
> > Issue 1: should the maximum heap size be unbounded by default?
> > Currently the maximum heap size is bounded at 64M. =20
> Arguments for: this
> > stops programs with a space leak eating all your swap=20
> space.  Arguments
> > against: it's annoying to have to raise the limit when you=20
> legitimately
> > need more space.
> >
> > Options:
> > 	1. remove the default limit altogether
> > 	2. raise the default limit
> > 	3. no change
> >
> > (any others?)
> >
> I think that if there should be a default limit it would be nice to be
> able to set it at compile time. This is something that I've wanted for
> quite some time. If I know that the program I am compiling is=20
> likely to
> need 100M of heap space it feels silly having to give the RTS=20
> parameter to
> the program each time I run it. It would be much more=20
> convenient to just
> tell the compiler where I want the limit.

You can do this using the hooks that the RTS provides, although it's a
bit inconvenient at the moment because as Sigbjorn points out we don't
ship the RtsFlags.h file which contains the definition of the flags
structure :-(

Documentation is here:
=09
=09
http://www.haskell.org/ghc/docs/latest/set/runtime-control.html#RTS-HOOK
S

You'll need to get RtsFlags.h from fptools/ghc/includes in a GHC source
distribution.

Cheers,
	Simon