[PATCH 2 of 2 V2] upgraderepo: add a config option for parallel computation

[Pierre-Yves David]

On 12/6/19 8:11 PM, Augie Fackler wrote:
> 
> 
>> On Dec 2, 2019, at 05:50, Pierre-Yves David <pierre-yves.david at ens-lyon.org> wrote:
>>
>> # HG changeset patch
>> # User Pierre-Yves David <pierre-yves.david at octobus.net>
>> # Date 1569765632 -7200
>> #      Sun Sep 29 16:00:32 2019 +0200
>> # Node ID 096a7d53095e3ecf883d1a743c84aaf8d4f15fe2
>> # Parent  eb24da344625c3c7c34ff71abce165889de3cc2f
>> # EXP-Topic sidedata-copies-perf
>> # Available At https://dev.heptapod.net/octobus/mercurial-devel/
>> #              hg pull https://dev.heptapod.net/octobus/mercurial-devel/ -r 096a7d53095e
>> upgraderepo: add a config option for parallel computation
> 
> queued, but I'd appreciate seeing numbers in the near-ash future for how much time this saves, or we should drop the use of multiprocessing IMO

For smaller repo this provide a significant boost. For example the total 
time of `hg debugupgraderepo --changelog --run` on pypy move from 352s 
to 120s (including the copying of the filelog/manifestlog).

On larger repository, it make things move from days to hours.

-- 
Pierre-Yves David