[PATCH] discovery: be more conservative when adjusting the sample size

[Pierre-Yves David]

On 6/6/19 7:40 AM, Martin von Zweigbergk wrote:
> 
> 
> On Wed, Jun 5, 2019 at 8:16 AM Pierre-Yves David 
> <pierre-yves.david at ens-lyon.org <mailto:pierre-yves.david at ens-lyon.org>> 
> wrote:
> 
> 
> 
>     On 6/5/19 3:21 PM, Martin von Zweigbergk wrote:
>      >
>      >
>      > On Wed, Jun 5, 2019, 03:36 Pierre-Yves David
>      > <pierre-yves.david at ens-lyon.org
>     <mailto:pierre-yves.david at ens-lyon.org>
>     <mailto:pierre-yves.david at ens-lyon.org
>     <mailto:pierre-yves.david at ens-lyon.org>>>
>      > wrote:
>      >
>      >     # HG changeset patch
>      >     # User Pierre-Yves David <pierre-yves.david at octobus.net
>     <mailto:pierre-yves.david at octobus.net>
>      >     <mailto:pierre-yves.david at octobus.net
>     <mailto:pierre-yves.david at octobus.net>>>
>      >     # Date 1559726605 -7200
>      >     #      Wed Jun 05 11:23:25 2019 +0200
>      >     # Node ID 2c67430451fafcdd68770436c520e2d008428986
>      >     # Parent  12793787439538411013edffe0f9b98762d38a37
>      >     # EXP-Topic discovery-large-undecided
>      >     # Available At https://bitbucket.org/octobus/mercurial-devel/
>      >     #              hg pull
>      > https://bitbucket.org/octobus/mercurial-devel/ -r 2c67430451fa
>      >     discovery: be more conservative when adjusting the sample size
>      >
>      >     Since 5b34972a0094, the discovery will increase the sample
>     size when
>      >     it detect a
>      >     "complex" undecided set. However this detection focussed on the
>      >     number of roots
>      >     only, this could regress discovery performance when the undecided
>      >     set has many
>      >     roots that eventually get merged into a few heads.
>      >
>      >
>      > Seems unlikely to happen in practice. That's why I didn't bother
>     with it
>      > in my patch.
> 
>     There are very common use case where this happens (eg: many feature
>     branch eventually merged into one head for integration testing).
> 
> 
> Right, that's the example I gave. I didn't mean that it seems unlikely 
> that there are fewer heads than roots, only that it seems unlikely that 
> there's a significant difference between them.

I saw two different cases where this is the case on a regular basis ;-)

-- 
Pierre-Yves David