[PATCH] gcc parallel make check
Tue Sep 16 09:48:00 GMT 2014
On Tue, Sep 16, 2014 at 11:28 AM, Jakub Jelinek <firstname.lastname@example.org> wrote:
> On Tue, Sep 16, 2014 at 11:20:37AM +0200, Richard Biener wrote:
>> > This confuses me, but, no matter. Isn’t 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
Ah, I assumed -j48 testing means you have 48 cores. I usually test
with -j12 on my 6-core HT-enabled box. A factor 15 scaling for 16
CPUs is of course close to the best we can achieve.
> 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.
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