Heads-up: new parallel I/O manager merged

Nicolas Trangez nicolas at incubaid.com
Mon Feb 25 11:44:25 CET 2013


On Mon, 2013-02-25 at 10:39 +0000, Svein Ove Aas wrote:
> In this day and age, it seems odd that we have to explicitly specify the
> number of cores. Detecting it would be pretty simple, on all systems I know
> of.

With some executable compiled using GHC 7.6.1 & threaded RTS, from +RTS
--help:

-N[<n>]   Use <n> processors (default: 1, -N alone determines
          the number of processors to use automatically)

Nicolas

> 
> Before I go ahead and write a patch, I'd there some technical or political
> reason we're boy doing that?
> On 25 Feb 2013 00:58, "Kazu Yamamoto" <kazu at iij.ad.jp> wrote:
> 
> > > We should really publish a blog post about this.
> >
> > - If we will take benchmark, "+RTS -Nx -qa -Aym" should be specified
> >   to a server. "y" should be changed according to "x", the number of
> >   core. I'm using "+RTS -N10 -qa -A32m" on a 12 core machine. "-qa"
> >   improves performance on Linux but not FreeBSD even if a "-qa" bug of
> >   GHC on FreeBSD is fixed.
> >
> >         http://hackage.haskell.org/trac/ghc/ticket/7708
> >
> > - "ab" sucks. We should use "weighttp" instead. I use as
> >         weighttp -n 1000000 -c 1000 -k -t 10 "http://X.Y.Z.W:8000/"
> >   which creates 10 native threads.
> >
> >   For more information, please refer to:
> >         http://gwan.com/en_apachebench_httperf.html
> >
> > http://www.iij.ad.jp/company/development/tech/activities/weighttp/index.html (in Japanese, sorry)
> >
> > --Kazu
> >
> > _______________________________________________
> > ghc-devs mailing list
> > ghc-devs at haskell.org
> > http://www.haskell.org/mailman/listinfo/ghc-devs
> >
> 
> In this day and age, it seems odd that we have to explicitly specify
> the number of cores. Detecting it would be pretty simple, on all
> systems I know of.
> 
> Before I go ahead and write a patch, I'd there some technical or
> political reason we're boy doing that?
> 
> On 25 Feb 2013 00:58, "Kazu Yamamoto" <kazu at iij.ad.jp> wrote:
>         > We should really publish a blog post about this.
>         
>         - If we will take benchmark, "+RTS -Nx -qa -Aym" should be
>         specified
>           to a server. "y" should be changed according to "x", the
>         number of
>           core. I'm using "+RTS -N10 -qa -A32m" on a 12 core machine.
>         "-qa"
>           improves performance on Linux but not FreeBSD even if a
>         "-qa" bug of
>           GHC on FreeBSD is fixed.
>         
>                 http://hackage.haskell.org/trac/ghc/ticket/7708
>         
>         - "ab" sucks. We should use "weighttp" instead. I use as
>                 weighttp -n 1000000 -c 1000 -k -t 10
>         "http://X.Y.Z.W:8000/"
>           which creates 10 native threads.
>         
>           For more information, please refer to:
>                 http://gwan.com/en_apachebench_httperf.html
>         
>         http://www.iij.ad.jp/company/development/tech/activities/weighttp/index.html  (in Japanese, sorry)
>         
>         --Kazu
>         
>         _______________________________________________
>         ghc-devs mailing list
>         ghc-devs at haskell.org
>         http://www.haskell.org/mailman/listinfo/ghc-devs
> _______________________________________________
> ghc-devs mailing list
> ghc-devs at haskell.org
> http://www.haskell.org/mailman/listinfo/ghc-devs





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