Re: [PATCH v3] meson: Pass -j option to sphinx

[Paolo Bonzini <pbonzini@redhat.com>]

On 4/28/23 17:01, Fabiano Rosas wrote:
> Also make sure our plugins support parallelism and report it properly
> to sphinx. Particularly, implement the merge_domaindata method in
> DBusDomain that is used to merge in data from other subprocesses.
> 
> before:
>    $ time make man html
>    ...
>    [1/2] Generating docs/QEMU manual with a custom command
>    [2/2] Generating docs/QEMU man pages with a custom command
> 
>    real    0m43.157s
>    user    0m42.642s
>    sys     0m0.576s
> 
> after:
>    $ time make man html
>    ...
>    [1/2] Generating docs/QEMU manual with a custom command
>    [2/2] Generating docs/QEMU man pages with a custom command
> 
>    real    0m25.014s
>    user    0m51.288s
>    sys     0m2.085s

The 'nproc' fallback will potentially cause twice #CPUs processes to be 
active, since sphinx will run in parallel with everything else.

Is this result with "-j auto", and if so with which computer?  If the 
speedup is only 2x as it seems to be from the "time" above, I'd rather 
have "-j 2" only so that sphinx doesn't risk killing the machine...

Paolo