top level make in under 8 seconds ...

Hi,

On Tue, Feb 18, 2014 at 05:13:44PM +0100, Bjoern Michaelsen wrote:
> On Tue, Feb 18, 2014 at 04:57:39PM +0100, Bjoern Michaelsen wrote:
> > 4.0, no maintainer mode, second run, using cache, power supply plugged, build on tmpfs:
> > real    0m11.155s

While at it I looked at the most costly things and found:

 https://gerrit.libreoffice.org/#/c/8111/

when that is on master the noop build is < 8 seconds.

With that fixed, the most expensive modules are:
> for mod in `find . -maxdepth 1 -type d|sed -e 's/^..//'`; do /usr/bin/time --format=%E:%C make 
> $mod.build 2>&1 ;done|grep :make|sort -n|tail -n 12
> 0:00.37:make sfx2.build
> 0:00.37:make xmloff.build
> 0:00.38:make vcl.build
> 0:00.40:make connectivity.build
> 0:00.45:make chart2.build
> 0:00.48:make filter.build
> 0:00.49:make dbaccess.build
> 0:00.71:make svx.build
> 0:00.82:make sd.build
> 0:01.22:make offapi.build
> 0:01.33:make sc.build
> 0:01.45:make sw.build

and building only these 12 with:
> make sw.build sc.build offapi.build sd.build svx.build dbaccess.build filter.build chart2.build 
> connectivity.build vcl.build xmloff.build sfx2.build
> real    0m7.894s

is already slower than:
> make build-nocheck
> real    0m7.776s

although the latter does check all > 200 modules.

So if we dont sneak in too many PHONYs, building top-level by default isnt
really that much of a burden -- after all usually, when you type 'make' you
actually rebuild something. ;)

And with that Im closing this years build system janitorial report and go back
to bumping distro releases.

Best,

Bjoern

(all measurements on notebook with SSD, no tmpfs and depcache make)