[Mesa-dev] [PATCH 20/25] anv: minor tweak in the generation script

[Emil Velikov]

On 22 April 2016 at 18:52, Jason Ekstrand <jason at jlekstrand.net> wrote:
> On Fri, Apr 22, 2016 at 10:27 AM, Emil Velikov <emil.l.velikov at gmail.com>
> wrote:
>>
>> On 22 April 2016 at 04:36, Kristian Høgsberg <krh at bitplanet.net> wrote:
>> > On Thu, Apr 21, 2016 at 5:18 PM, Emil Velikov <emil.l.velikov at gmail.com>
>> > wrote:
>> >> On 21 April 2016 at 22:50, Jason Ekstrand <jason at jlekstrand.net> wrote:
>> >>> On Thu, Apr 21, 2016 at 6:16 AM, Emil Velikov
>> >>> <emil.l.velikov at gmail.com>
>> >>> wrote:
>> >>>>
>> >>>> From: Emil Velikov <emil.velikov at collabora.com>
>> >>>>
>> >>>> Rather than parsing through the same files (public headers) twice,
>> >>>> tweak
>> >>>> the python script to create both files at the same time.
>> >>>
>> >>>
>> >>> Yes, but it takes almost zero time to generate them and it's going to
>> >>> run in
>> >>> parallel before anything else gets built.  I don't know that this
>> >>> really
>> >>> saves us anything.
>> >>>
>> >> Are you sure about this one? Based on my brief testing - things were
>> >> pretty much stalled until both files were generated. I'll take another
>> >> look.
>> >>
>> >> If anything the approach cuts down the bash output redirection and
>> >> some nasty handling around it.
>> >> Talking about the following $(PYHON) ....  > $@ || ($(RM) $@; false)
>> >> and how often we forget to add it.
>> >>
>> Things get stalled for all the sources to be generated before proceeding
>> with
>> the compilation. Thus there isn't much benefit with the current approach
>> afaict.
>
>
> Yes, but if they run in parallel (which they will on *any* modern machine),
> then it only takes as long as the longest one takes to run.  I don't think
> it's actually helping anything to do them both with one python invocation
> except for the make -j1 case.
>
Which afaict does not make any difference, as the overhead of starting
a second instance mitigates any benefits. Also there is the makefile
simplification/bugfix.

-Emil