[yocto] Update on build time performance - not good

[Koen Kooi]

Op 10 jun 2011, om 10:44 heeft Richard Purdie het volgende geschreven:

> We've merged a number of things which should have helped performance
> recently. Changes in my test included:
> 
> * Splitting out the locale generation [not merged yet]
> * Not building tar-replacement-native when we don't need it
> * Cleaned up dependencies for native/nativesdk
> * Cleaned up dependencies for all-arch packages
> * Reduced dbus-native dependencies
> 
> The time for the benchmark timing test against master with the locale
> split patch applied was:
> 
> real	105m5.813s
> user	386m39.170s
> sys	59m40.250s
> 
> so not that much different from where we have been :(.
> 
> I did observe things through the build process:
> 
> * The first part of the build was *fast* getting through the first 2000 
>  of 4295 tasks in about 10 minutes.
> * The CPU usage was pretty much full for that time
> * The next 5 minutes covered the next 150 tasks
> * gettext-native didn't seem to get built until surprisingly late in 
>  the process
> * There was a highly serialised chain of gettext-native, libelf-native, 
>  binutils-native, binutils-cross etc.
> * Once eglibc/libgcc completed, processor usage was high again for the 
>  rest of the build
> 
> I'm hoping my BB_NUMBER_THREADS (12 on a quad core machine) was too high
> causing too much context switching and as the build process might now be
> more efficient, lowering it might help. I am a bit disappointed in those
> numbers though.

Do you have pretty bootchart graphs for that?

regards,

Koen