[Mesa-dev] [PATCH 8/9] nir: move to compiler

[Emil Velikov]

On 16 December 2015 at 01:13, Jason Ekstrand <jason at jlekstrand.net> wrote:
> On Sat, Nov 28, 2015 at 8:45 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>> On 27 November 2015 at 20:45, Jason Ekstrand <jason at jlekstrand.net> wrote:
>>> On Nov 27, 2015 11:26 AM, "Matt Turner" <mattst88 at gmail.com> wrote:
>>>> On Fri, Nov 27, 2015 at 6:50 AM, Emil Velikov <emil.l.velikov at gmail.com>
>>>> wrote:
>>>> > On 25 November 2015 at 22:01, Matt Turner <mattst88 at gmail.com> wrote:
>>>> >> On Wed, Nov 25, 2015 at 1:32 PM, Emil Velikov
>>>> >> <emil.l.velikov at gmail.com> wrote:
>>>> >
>>>> >>> --- a/src/Makefile.am
>>>> >>> +++ b/src/Makefile.am
>>>> >>> @@ -23,6 +23,7 @@ SUBDIRS = . gtest util mapi/glapi/gen mapi
>>>> >>>
>>>> >>>  # XXX: conditionally include
>>>> >>>  SUBDIRS += compiler
>>>> >>> +SUBDIRS += compiler/nir
>>>> >>
>>>> >> We have a non-recursive build in src/glsl today. I don't want to go
>>>> >> backwards.
>>>> > Not sure I fully get that can you elaborate ? Are you concerned that
>>>> > things won't build in parallel, increasing the compilation times ?
>>>> >
>>>> > On my dual core system running with -j2 results in approx 15 seconds
>>>> > increase. I'm willing to take that trade off for the improved
>>>> > readability. What is the difference on your system ?
>>>>
>>>> src/glsl has single Makefile that builds libglcpp, glcpp, libglsl,
>>>> glsl_compiler, glsl_test, libnir, and various test programs, allowing
>>>> all of these things to happen in parallel. The Makefile is perfectly
>>>> maintainable as it is and there's no advantage of splitting it,
>>>> especially when the work has been done to get things to this state
>>>> (commits 86d30dea, efd201ca) and NIR was added without an additional
>>>> Makefile.
>>>
>>> I would tend to agree.  Making things hierarchical is nice but,
>>> unfortunately, autotools makes this and parallelization mutually exclusive.
>>
>> Actually I have some ancient work where we benefit from both. Namely
>> have a single top level Makefile.am, which directly includes the
>> subdirectory Automake.mk files, resulting in one big Makefile at the
>> very end.
>>
>> That aside can we get some quantitative representation of the penalty
>> you guys see. On my (old) machine the difference is negligible  ~15
>> sec of a ~11 minute `make all' and ~16 minute `make distcheck'.
>
> What happened to this?  (Yes, "Busy doing a release" is a valid answer)

There is a question in there for which I was waiting for an answer.
Here it is again - split from the rest, with a question mark (silly
me).

Can anyone confirm how much of a penalty are we talking about (single
vs separate makefiles) ?

Getting these makefiles benefit from parallelism, whist retaining the
split, is reasonably straight forward*.

Thanks
Emil

* Once we find out how to "hack" scons. Will contact Jose and others
on the topic shortly.