On 2015-02-22 8:04 AM, Richard Purdie wrote:
As people know, I've been looking at performance a little, one of the
benchmarks is how long the kernel takes to build. I dumped out the task
performance data from buildstats for a linux-yocto build (nothing else
running):
do_fetch: Elapsed time: 0.04 seconds
do_unpack: Elapsed time: 1.61 seconds
do_kernel_checkout: Elapsed time: 4.39 seconds
do_validate_branches: Elapsed time: 0.47 seconds
do_patch: Elapsed time: 57.77 seconds
do_kernel_configme: Elapsed time: 44.92 seconds
do_kernel_configcheck: Elapsed time: 8.94 seconds
do_configure: Elapsed time: 0.60 seconds
do_compile: Elapsed time: 72.95 seconds
do_compile_kernelmodules: Elapsed time: 34.84 seconds
do_populate_lic: Elapsed time: 0.14 seconds
do_strip: Elapsed time: 0.03 seconds
do_uboot_mkimage: Elapsed time: 0.03 seconds
do_install: Elapsed time: 1.87 seconds
do_populate_sysroot: Elapsed time: 0.16 seconds
do_shared_workdir: Elapsed time: 0.05 seconds
do_sizecheck: Elapsed time: 0.03 seconds
do_bundle_initramfs: Elapsed time: 0.03 seconds
do_kernel_link_vmlinux: Elapsed time: 0.03 seconds
do_deploy: Elapsed time: 13.17 seconds
do_package: Elapsed time: 31.54 seconds
do_packagedata: Elapsed time: 0.59 seconds
do_package_qa: Elapsed time: 5.30 seconds
do_package_write_ipk: Elapsed time: 83.24 seconds
do_package_write_rpm: Elapsed time: 44.58 seconds
The "core" was getting blamed for a lot of the build time. As can be
seen, the "core" isn't taking that much time now, apart from the fact
that ipk packaging seems to be taking twice the time of rpm which needs
looking into.
Some tasks like the compile tasks are understandable and likely
minimised by upstream work already.
The other tasks which as consuming a disproportionate amount of time are
kernel_configme and patch, I believe we need to look into those a little
further too. To put it into context, should the kernel compile be at the
same order of magnitude as the patch and configure?
Was this the 3.19 kernel you used for these stats ? I just ran a quick
test (i.e. not with buildstats) with my latest kernel tree (on my
crappy I/O laptop) and get the following:
% time bitbake -f -c kernel_configme linux-yocto
real 0m7.378s
user 0m4.356s
sys 0m5.553s
So I'm showing 7 seconds, versus 45 in your run .. and I'm showing:
real 0m26.371s
user 0m12.561s
sys 0m19.534s
For do_patch (and that is before the already in progress changes that
I mentioned earlier).
Just with those differences alone, sounds like we should log this in
bugzilla and put the details of the configuration and build machines in
there .. since I'll need to isolate what is causing those extra long
runs, and ensure that everything is pushed to the various trees.
Cheers,
Bruce
Cheers,
Richard
--
_______________________________________________
Openembedded-core mailing list
Openembedded-core@lists.openembedded.org
http://lists.openembedded.org/mailman/listinfo/openembedded-core
