[OE-core] Accelerate do_package

[Jack Mitchell]

On 12/10/12 12:43, Samuel Stirtzel wrote:
> Hi,
> after re-building Qt the third time today, I was curious why
> do_package takes this long.
>
>  From my investigation it looks like the library stripping is the culprit,
> it lets my system idle with 5% CPU usage over a long time.
>
> Would it be possible to accelerate do_package with parallelisation?
> Likely I could look into this sometime soon, but I'd rather hear your
> thoughts on this first.
>
>
> PS:
> Also sstate creation and rootfs packing could be made faster with
> pbzip2 [1] / pigz [2] (we have a recipe for pigz), or is anthing
> preventing this?
>
> [1] http://compression.ca/pbzip2/
> [2] http://zlib.net/pigz/
>
>

Samuel,

You being up an interesting point here as I have recently been mulling 
over ways of improving performance. I believe performance improvements 
are one of the targets of the 1.4 yocto/oe-core release so it will be 
properly discussed then.

In the meantime a couple of points I was thinking about related to 
improving performance was by deeming some tasks as "non active" such as 
they didn't take up a thread of your total specified. This could be 
applied to low-cpu intensive tasks such as do_fetch and do_package which 
I believe would greatly speed up the build and make more efficient use 
of the CPU.

As for using pbzip2/pigz I believe there was a discussion on it and 
something was said regarding the compatibility of the created archives. 
For example an archive created by pigz could sometimes not be 
uncompressed by gzip, I am just remembering this from memory though, I'm 
sure a search of the list would be more enlightening.

Regards,

-- 

   Jack Mitchell (jack at embed.me.uk)
   Embedded Systems Engineer
   http://www.embed.me.uk

--