[Pharo-project] new Cog VMs uploaded

Eliot Miranda eliot.miranda at gmail.com
Tue May 3 23:40:05 CEST 2011


On Tue, May 3, 2011 at 11:57 AM, Philippe Marschall <kustos at gmx.net> wrote:

> On 03.05.2011 19:51, Eliot Miranda wrote:
> >
> >
> > On Sun, May 1, 2011 at 4:38 AM, Philippe Marschall <kustos at gmx.net
> > <mailto:kustos at gmx.net>> wrote:
> >
> >     On 29.04.2011 19:03, Eliot Miranda wrote:
> >     >
> >     >
> >     > On Fri, Apr 29, 2011 at 9:04 AM, Philippe Marschall
> >     <kustos at gmx.net
> >     <mailto:kustos at gmx.net>
> >     > <mailto:kustos at gmx.net
> >     <mailto:kustos at gmx.net>>> wrote:
> >     >
> >     >     On 27.04.2011 19 <tel:27.04.2011%2019>
> >     <tel:27.04.2011%2019>:23, Eliot Miranda wrote:
> >     >     > Philippe,
> >     >     >
> >     >     >     can you please profile before and after?  This could
> >     very well
> >     >     be to
> >     >     > do with the additional cost of shallowCopy for contexts, but
> >     it is
> >     >     > inevitable that a correct implementation is going to be more
> >     expensive
> >     >     > than the simple block-copy.  The new implementation can be
> >     optimized,
> >     >     > but we need to profile first to be sure we're tilting at the
> >     relevant
> >     >     > windmill.
> >     >
> >     >
> >     >     What kind of profiling do you have in mind, MessageTally?
> >     >
> >     >
> >     > Yes, that would be fine.  Thanks!
> >
> >     OK, there you go. As you'll see the runtime is about the same, that's
> >     because we do more iterations in the same time. Also note the time
> we're
> >     spending in WriteStream >> #nextPutAll: with interestingly has a
> >     different growing behavior than WriteStream >> #nextPut: (only 25% vs
> >     100%). I already raised the issue once but people argued that the
> >     current code is prefect.
> >
> >
> > Hmmm.  GC behaviour is very different.  Also requestContext Also shows
> > up in the 2382 profiles but not the 2370 traces.  You'll need to dig a
> > little deeper to account for these differences.  I guess they could well
> > be to do with the new (correct) MethodContext copying behaviour
> > retaining more state and hence stressing the GC more.
>
> What approach do you suggest should I take?
>

I have no idea.  You could try and break down the various activities and
benchmark them separately I suppose.  You could look at the profiles you're
already generating in higher resolution to see where the time is going.  You
could also try and extract the SystemProfiler from OpenQwaq, which will run
on Cog, and is better than MessageTally.  Andreas wrote it to get around
some of MessageTally's limitations.  It should hopefully show primitives
quite accurately.

HTH
Eliot


>
> Cheers
> Philippe
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gforge.inria.fr/pipermail/pharo-project/attachments/20110503/27c20a4c/attachment.htm>


More information about the Pharo-project mailing list