The part I dread the most of doing `emerge --update --deep --newuse world` is whenever there is an update for sci-libs/blas-atlas or sci-libs/lapack-atlas, simply because it takes a VERY long time to tune the configuration--the Automatically Tuned part of Automatically Tuned Linear Algebra System. Given that, my system, and probably many others, are usually under a relatively stable load, it would be great if there was a method for saving the final configuration for these packages to skip the hours-long process of tuning, much like USE="savedconfig" available for sys-apps/busybox Would this be possible, or did I completely misunderstand how the automatic tuning process works? Reproducible: Always Steps to Reproduce:
Hi Ariel, Thanks for your note! We are actually already re-using some of the timings generated by blas-atlas (they are in /usr/include/atlas) when emerging lapack-atlas which is why the latter compiles relatively fast. As a matter of fact, atlas comes with a fairly extensive number of pre-tuned timings for a variety of CPUs (they are in ATLAS/CONFIG/ARCHS) and if your machine is among them atlas does not go through a full blown tuning process and compiles in less than two hours even on my 5 year old P4. Hence, only users with CPUs not covered by the atlas devs end up with long compile times. I presume this is the case for your CPU? That said, I am not quite sure at the moment how difficult it would be to implement what you are envisioning inside our ebuild, but I will have a look. In any case, obtaining a good set of timings is more involved than just running a single tuning session and involves multiple runs with some sort of averaging procedure; hence, it would be much better if upstream could include your CPU in their list of pre-generated timings. Maybe you can ping them about it. Best, Markus
using a P4-32bit, bottleneck must be somewhere else... but now i know it will take a long time... resolving as invalid - upstream source already includes functionality
