[PATCH 2 of 6] scripts: docs-headings: distribute over available CPU cores

[Thomas De Schampheleire]

El dom., 30 dic. 2018 a las 0:45, Mads Kiilerich
(<mads at kiilerich.com>) escribió:
>
> On 12/29/18 10:50 PM, Thomas De Schampheleire wrote:
> > # HG changeset patch
> > # User Thomas De Schampheleire <thomas.de_schampheleire at nokia.com>
> > # Date 1546110972 -3600
> > #      Sat Dec 29 20:16:12 2018 +0100
> > # Node ID a7df630cfe21e5e66c555b9fa88ef2c3930870b1
> > # Parent  6caed3c13cb8d631430371b8e1141a724c4c4cae
> > scripts: docs-headings: distribute over available CPU cores
> >
> > This script is only relevant for contributors, and the fact that it is quite
> > slow is normally not a big problem.
> > However, when running it in iteration on different commits, as preparation
> > to sending out a series, its slowness becomes annoying.
>
>
> Yeah, the script takes something like 30s to run for me.

I guess you don't have an SSD?
On my side the original script takes about 8 seconds.

>
> But most of the time is spent running 'hg diff' once for each file. Just
> the part of your change that moves it to a simple diff call takes it
> down to less than one second.
>
> The parallelization doesn't seem to save additional time. Perhaps
> because I don't have many cores. But is it really worth the extra
> complexity? Then let's assess the parallelization separate from the
> single hg invocation.

Good catch, I hadn't done any profiling :-s

I see the same: just reducing the 'hg diff' invocations brings my 8
seconds to 0.5 seconds, and parallelizing doesn't improve it further.
I'll send a new version.

/Thomas