[yocto] nightly-release takes more than 24 hours to build.

[Scott Garman]

Hello,

Leading up to our 0.9 release, our autobuilder has been building an 
increasing number of targets for our nightly-release buildset. We've now 
reached the point that the nightly build takes more than 24 hours to run 
(> 26 hours, in fact) - which is clearly a problem on a build that we'd 
like to generate on a daily basis.

The following is a list of everything which is built within nightly-release:

The following targets are built for qemux86, qemux86-64, qemuarm, 
qemumips, and qemuppc:

* poky-image-minimal
* poky-image-sato
* poky-image-lsb
* poky-image-sdk
* meta-toolchain-sdk (SDKMACHINE=i586 and also x86_64)

For emenlow and atom-pc, we build:

* poky-image-minimal-live
* poky-image-sato-live
* poky-image-sdk-live
* meta-toolchain-sdk (SDKMACHINE=i586 and also x86_64)

Finally, we also build the Eclipse plugin, and copy the shared state 
prebuilds and RPM output at the end of the build.

I was going to post build times for some of these targets for reference, 
but it would be misleading as we build the targets in succession (e.g, 
we start with poky-image-sdk which takes the bulk of the time, and then 
the other targets can largely rely on the shared state builds).

Ideally I think our nightly build should take much less than 24 hours to 
build. The question is what we can move out of the nightly build and do 
on perhaps a weekly basis instead?

Our buildserver hardware is a dual quad-core Xeon server with 12 GB of 
RAM. Throwing hardware at the problem is another solution, but not an 
inexpensive one (we'd be looking at a 4-socket machine filled with 
quad-cores and 32 GB of RAM).

I'm open to ideas on how to address this issue. QA will be driving a lot 
of the requirements and I'm especially interested to hear your thoughts.

Scott