Re: RTS changes affect runtime when they shouldn’t

[Sebastian Graf]

Hi,

I did it for my thesis and I found it ok. I mean I always sent it off
> to some machine and looked at the results later, so I did not really
> care whether it took 30mins or 2h.


I did the same for my thesis (the setup of which basically was a rip-off of
Joachim's) and it was really quite bearable. I think it was even faster
than doing NoFibRuns=30 without counting instructions.

The only real drawback I see is that instruction count might skew results,
because AFAIK it doesn't properly take the architecture (pipeline,
latencies, etc.) into account. It might be just OK for the average program,
though.

On Wed, Sep 20, 2017 at 10:13 PM, Joachim Breitner <mail at joachim-breitner.de
> wrote:

> Hi
>
> Am Mittwoch, den 20.09.2017, 14:33 -0400 schrieb Ben Gamari:
> > Note that valgrind can also do cache modelling so I suspect it can give
> > you a reasonably good picture of execution; certainly better than
> > runtime. However, the trade-off is that (last I checked) it's incredibly
> > slow. Don't you think I mean just a bit less peppy than usual. I mean
> > soul-crushingly, mollasses-on-a-cold-December-morning slow.
> >
> > If we think that we can bear the cost of running valigrind then I think
> > it would be a great improvement. As you point out, the current run times
> > are essentially useless.
>
> I did it for my thesis and I found it ok. I mean I always sent it off
> to some machine and looked at the results later, so I did not really
> care whether it took 30mins or 2h.
>
> I think I’ll try it in perf.haskell.org and see what happens.
>
> Joachim
> --
> Joachim “nomeata” Breitner
>   mail at joachim-breitner.de
>   https://www.joachim-breitner.de/
>
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