[OE-core] Meson support in oe-core

[Randy MacLeod]

On 2017-08-07 09:47 AM, Alexander Kanavin wrote:
> On 08/07/2017 04:00 PM, Richard Purdie wrote:
> 
>> Thanks for looking at this. Whilst some project still have some support
>> for both, could we get timings of do_{configure|compile|install} for
>> autotools vs. meson?
> 
> So far there's just one recipe that I can test, json-glib, which is 
> fairly small, and so there's not a lot of difference between 
> compile+install steps. configure however is vastly faster:
> 
> autotools with gtk-doc
> 
> configure 16.53
> compile 12.56
> install 1.94
> total 31.03
> 
> meson with gtk-doc
> 
> configure 2.04
> compile 4.87
> install 9.16
> total 16.07
> 
> autotools without gtk-doc
> configure 16.26
> compile 5.49
> install 1.59
> total 23.34
> 
> meson without gtk-doc
> configure 1.95
> compile 5.04
> install 2.26
> total 9.25

Yep, total time for 'without gtk-doc' is *more* than cut in half!

The drop in configure time is certainly expected but the compilation
stage should be dominated by the compiler rather than make or ninja.
The 'without gtk-doc' compile difference mostly confirms that
but the 9% drop is odd. A couple of sources I've found assert that
for large projects and parallel builds a full build time is essentially
the same with ninja:
    http://david.rothlis.net/ninja-benchmark/
That work was done on a MacBook (!!) so it would be interesting to
see what the results are on a 24+ core Linux system. I might
give that a try tonight if there's nothing good on NetFlix.

By the way, systemd-234 has meson support and you (Alex) have sent
a patch update to 242 to the oe-core list but without switching to meson
as is reasonable. Anyway, 232 takes 51 seconds on my 16+16 core machine
so it would be a useful benchmark as well. Want to take a stab at that?

../Randy



> 
> 
> Alex


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