Re: [PATCH 1/1] libc-locale: split locale handling from libc recipe.

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2011-06-08 at 10:36 +0100, Phil Blundell wrote:
> On Wed, 2011-06-08 at 17:08 +0800, Dongxiao Xu wrote:
> > *libc's do_package will cost a lot of time due to the locale handing,
> > which may delay the other recipe's do_package task and affect the build
> > performance.
> > 
> > This commit moves locale handling into a separate recipe *libc-locale.
> 
> Can you quantify the effect on build performance a bit?  If I understand
> correctly, you're basically saying that the goal is to increase
> parallelism.  Does that cause reduced performance for people running
> with few threads?

One of the side effects of debian.bbclass is that it requires all
dependencies to do_package before any package itself can do_package so
any renaming of dependencies can be accounted for.

There is an issue if do_package for libc takes an age as it holds up any
other tasks from writing out packages. Pretty much most things depend on
libc.

This patch therefore splits it into two stages and means that packaging
of things depending on libc can happen sooner thereby increasing the
potential parallelism of the packaging stages of builds.

There is a very clear step on the "bootchart" graphs of builds I made
showing this.

I'm not sure how this would reduce performance of builds of a few
threads, it should just make better use of any available "spare"
processing capacity throughout the build.

Cheers,

Richard