On 1/12/19 9:34 AM, Khem Raj wrote:
On Wed, Jan 9, 2019 at 11:17 PM Robert Yang <liezhi.y...@windriver.com
<mailto:liezhi.y...@windriver.com>> wrote:
Hi,
I reimplemented glibc's site config and did a lot of tests recently,
finally,
I found that it isn't as useful as I had thought, so I'm leaning to remove
classes/siteconfig.bbclass.
* Here are the test results of with/without glibc's siteconfig:
$ bitbake recipe -cconfigure && bitbake recipe -ccleansstate && time bitbake
recipe -cconfigure
- gettext:
without: 2m38.382s
with: 2m33.099s
- coreutils:
without: 1m19.967s
with: 1m13.574s
- bison:
without: 0m56.203s
with: 0m50.134s
These 3 recipes' do_configure are very time consuming, we can see that it
saves
about 6s for bison/coreutils/gettext's do_configure, but they need depend on
glibc's site config recipe (glibc-site.bb <http://glibc-site.bb>), while
glibc-site requires about 30s
to build, so if we count glibc-site's 30s, it seems not worth. And I also
tested
again and again on core-image-minimal and core-image-sato with/without
glibc's
siteconfig, there is nearly no difference, about 30s in 30m (1.6%)'s
differences, this maybe because of host rather than siteconfig. So I think
that
we can remove classes/siteconfig.bbclass since it is not as useful as
expected.
I've also tested remove siteconfig.bbclass (zlib and ncurses use it), there
is
no difference when "time bitbake core-image-minimal".
The new implementation for glibc's site config is:
- Add a recipe called glibc-site_2.28.bb <http://glibc-site_2.28.bb>, find
out the top 100 used functions
and headers, and add them to site_config/funcs and site_config/headers.
Please
see patches' commit message on how to find out the top 100.
- Make target/nativesdk recipes depend on glibc-site when inherit
autotools.bbclass
Here are the 2 patches:
git://git.openembedded.org/openembedded-core-contrib
<http://git.openembedded.org/openembedded-core-contrib> rbt/glibc-site
http://cgit.openembedded.org/openembedded-core-contrib/log/?h=rbt/glibc-site
Please feel free to give your comments, and I will remove it if no
objections.
I think if we cache all values then It probably will be faster but partial
Cache more values would make glibc-site requires more time to build, and all
autotools recipes depend on glibc-site, so I think that it's not worth to cache
more, so I chose top 100 (the ones which are re-used more than about 20 times)
to cache in a world build.
caching will give results like you see what will be interring to see is world
build time differences when doing build from scratch
But it indeed sounds a over optimization
I didn't test world's build time since it requires a lot of time, but refer to
core-image-minimal and sato, I think that there is no difference with world
build since we're doing parallel build, and the recipes which require a lot of
time to configure are already covered by sato build (such as gettext, coreutils
and bison).
// Robert
--
Thanks
Robert
--
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