Re: [4.9-rc1] Build-time 2x slower

[Ming Lei]

On Tue, Oct 18, 2016 at 12:04 AM, Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> Hi Linus,
>
> not sure whom to address on this issue.
>
> I have built Linux v4.9-rc1, v4.8.2 and v4.4.25 kernels (in this
> order) this morning.
>
> Building a Linux v4.8.2 under Linux v4.9-rc1 took two times longer.
>
> As usually I build with 2 parallel-make-jobs.
> This takes approx. 30mins.
> Under Linux v4.9-rc1 it took approx. an hour.
>
> My system is a Ubuntu/precise AMD64 (WUBI installation).
> I use my normal build-environment.
>
> If you need further informations, please let me know.

Kernel building is more like a CPU-bound workload, so maybe
some clues can be got by comparing results of 'perf top/record',
which should be very easy to collect.

>
> Regards,
> - Sedat -
>
> P.S.: Listing content of attached tarball file.
>
> $ LC_ALL=C ls -R
> .:
> build-time  configs  scripts  toolchain-amd64
>
> ./build-time:
> ls-alt_building-4-4-25-under-4-8-2.txt
> ls-alt_building-4-8-2-under-4-9-0-rc1.txt
>
> ./configs:
> WHATS-IN-DILEKS-LINUX-KERNEL.txt  config-4.4.25-1-iniza-small
> config-4.8.2-1-iniza-small  config-4.9.0-rc1-1-iniza-small
>
> ./scripts:
> build_linux-upstream.sh
>
> ./toolchain-amd64:
> HOST-AND-BUILD-TOOLCHAIN.txt



Thanks,
Ming Lei