#984 Speeding up configure

Metadata

Property	Value
Reported by	Christoph Grüninger (gruenich@iws.uni-stuttgart.de)
Reported at	Dec 2, 2011 22:47
Type	Discussion
Version	Git (pre2.4) [autotools]
Operating System	Unspecified / All
Last edited by	Christoph Grüninger (gruenich@iws.uni-stuttgart.de)
Last edited at	Mar 11, 2012 10:23
Closed by	Christoph Grüninger (gruenich@iws.uni-stuttgart.de)
Closed at	Mar 11, 2012 10:23
Closed in version	Unknown
Resolution	Implemented
Comment	Documented in a newly created section in buildsystem-howto.
Added in recent changes on the homepage.

Description

I am annoyed by Dune's sluggish build process. I hoped CMake might speed up the autogen and configure part. Lately Robert pointed [0] to autotool's configure cache [1]. I tried it and for dunecontontrol --opts=... --module=dune-pdelab configure it took 49 seconds without and 29 seconds with caching. I deleted the cache before the run and it was created by the first occurrence of a test. For my working configuration with dune-multidomain and dumux-devel I expect an ever higher benefit.

Because I would not like to waste 20 s a gazillion of times, I want to include caching in dunecontrol similar to the resume function. For every configure I would delete the old cache and use the cache only for successive dune modules in the same configure run.

Libraries like dunecommon are currently not cached because we use our own test DUNE_* instead of AC_CHECK_LIB / AC_SEARCH_LIBS. The latter has built-in caching [2] but I think we can include this in most of our own macros.

I will investigate this further and create patches in a not too remote future.

But I'm afraid of Donald Knuth statement: "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil"

[0] http://lists.dune-project.org/pipermail/dune/2011-November/009736.html [1] http://www.gnu.org/s/hello/manual/autoconf/Caching-Results.html [2] http://www.gnu.org/s/hello/manual/autoconf/Libraries.html