From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 28 Jan 2021 20:20:32 GMT
Subject: Re: [PATCH 0/3] Speed up remove_redundant()
Message-ID: <xmqqzh0svmnj.fsf@gitster.c.googlers.com>
In-Reply-To: <pull.852.git.1611851095.gitgitgadget@gmail.com>

"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:

> Michael Haggerty pointed out that git merge-base --independent is quite slow
> when many commits are provided in the input. This boils down to some
> quadratic behavior in remove_redundant() because it calls
> paint_down_to_common() in a loop.
>
> This series avoids that by using a single commit walk, pushing a flag that
> means "this commit is reachable from a parent of a commit in the list." At
> the end of the walk, the input commits without that flag are independent.

Yay.  I've been quite unhappy with the loop ever since I wrote it
back in 2012.

Thanks for cleaning it up.