Re: [darcs-users] Re: [BK] upgrade will be needed

Ralph Corderoy
2005-02-20T10:36:53Z

Hi,

David Roundy, creator of darcs, wrote:
> On Sat, Feb 19, 2005 at 05:42:13PM +0100, Andrea Arcangeli wrote:
> > I read in the webpage of the darcs kernel repository that they had
> > to add RAM serveral times to avoid running out of memory. They
> > needed more than 1G IIRC, and that was enough for me to lose
> > interest into it. You're right I blamed the functional approach and
> > so I felt it was going to be a mess to fix the ram utilization, but
> > as someone else pointed out, perhaps it's darcs to blame and not
> > haskell. I don't know.
>
> Darcs' RAM use has indeed already improved somewhat... I'm not exactly
> sure how much. I'm not quite sure how to measure peak virtual memory
> usage, and most of the time darcs' memory use while doing the linux
> kernel conversion is under a couple of hundred megabytes.

Wouldn't calling sbrk(0) help? I don't know if the Haskell run-time
ever shrinks the data segment, if not, it could just be called at the
end. Or a `strace -e trace=brk darcs ...' might do. But I guess darcs
has other VM usage that doesn't show in this figure? Does /proc/$$/maps
if running under Linux help?

A consistent way to measure would be handy for observing changes over
time.

Cheers,

Ralph.