[OE-core] [RFC] Performance Issue: Build time increases
lianhao.lu at intel.com
Fri Aug 12 14:19:21 CEST 2011
Robert Yang wrote on 2011-08-12:
> Hi folks,
> The build time of core-image-sato increases about 5 ~ 10 minutes than
> the following commit:
> commit 5af197b55a4b779f1ec93186f0723026949ba2b5
> Author: Liping Ke <liping.ke at intel.com>
> Date: Fri Jun 3 08:22:40 2011 +0800
> cache: Implement multiple extra cache fields request support
I think this patch only stores extra information in an extra cache. It only affects the parsing time, and I don't think there will be 5 min difference. How about comparing the "bitbake -e" time with and without the patch(by deleting all the cache files before running bitbake).
> On my host,
> 1) the build time of 5af197b55a4b779f1ec93186f0723026949ba2b5 is:
> real 208m26.133s
> user 241m29.280s
> sys 47m0.630s
> 2) and: 068839698fe192d8846c0ed4db65861448e8e524 is:
> real 217m39.687s
> user 255m34.150s
> sys 48m21.510s
> I use the bisect build method to find out which patch causes the time
> increases, but the build time is not stable on my host(Ubuntu 11.04
> 64bit), e.g., the build time of 1) is 208m at the first build, then
> "git co other_commit" and build it, after about 10 builds, then go
> back to build 5af197b55a4b779f1ec, the build time will increases about
> 8 minutes, I have stopped the X and cron, at. This may have relationship with the linux distribution and disk.
> So I have to restart the build, reboot the machine by two days, and go
> on the build. It would be better if anyone has other good method.
> I think that for the next release(e.g., yocto 1.2), we can find a
> clean and stable machine(for the distribution, maybe RHEL is more
> stable than Ubuntu) to check the build time weekly, so that we can notice the performance issue early.
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