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Re: [PATCH] gcc parallel make check
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: Mike Stump <mikestump at comcast dot net>, VandeVondele Joost <joost dot vandevondele at mat dot ethz dot ch>, David Malcolm <dmalcolm at redhat dot com>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>, "fortran at gcc dot gnu dot org" <fortran at gcc dot gnu dot org>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, "libstdc++ at gcc dot gnu dot org" <libstdc++ at gcc dot gnu dot org>
- Date: Tue, 16 Sep 2014 11:28:30 +0200
- Subject: Re: [PATCH] gcc parallel make check
- Authentication-results: sourceware.org; auth=none
- References: <20140911075123 dot GN17454 at tucnak dot redhat dot com> <20140911080640 dot GP17454 at tucnak dot redhat dot com> <20140911145300 dot GR17454 at tucnak dot redhat dot com> <908103EDB4893A42920B21D3568BFD93150F876D at MBX23 dot d dot ethz dot ch> <908103EDB4893A42920B21D3568BFD93150FE8D2 at MBX13 dot d dot ethz dot ch> <20140912163241 dot GC17454 at tucnak dot redhat dot com> <305370A6-ACBC-4DD4-AF96-32B3503F3388 at comcast dot net> <20140915160549 dot GM17454 at tucnak dot redhat dot com> <64B425D3-EDE8-4F28-B815-F9D374730F7F at comcast dot net> <CAFiYyc2TpoHsCtXospY96S4=17kbBce-c8EcV1S5=b-hcbp-Vg at mail dot gmail dot com>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Tue, Sep 16, 2014 at 11:20:37AM +0200, Richard Biener wrote:
> > This confuses me, but, no matter. Isnât 8hrs time data? :-)
It is, but not time(1) data, just wall clock computed from subtracting
mtimes of my make check output log and make -j48 bootstrap log.
> >> patch toplevel make -j48 -k check took:
> >> real 40m21.984s
> >> user 341m51.675s
> >> sys 112m46.993s
> >> and with the patch make -j48 -k check took:
> >> real 32m22.066s
> >> user 355m1.788s
> >> sys 117m5.809s
> >
> > These numbers are useful to try and ensure the overhead (scaling factor) is reasonable, thanks.
>
> A nice improvement indeed. The patched result is 15 times faster
> than the serial unpatched run. So there is room for improvement
Note, the box used was oldish AMD 16-core, no ht, box, haven't tried it on anything
more parallel, also it was normal hard disk, etc. No idea whether anything
from this is relevant to that though.
Some CPU time goes into the expect processes, I can retry the build tonight
and grab also time(1) info from make -k check to see the user/sys times for
serial testing.
Jakub