Re: [PATCH] git-status.txt: mention --no-optional-locks

From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Jonathan Nieder <jrnieder@gmail.com>,
	Nathan Neulinger <nneul@neulinger.org>,
	Santiago Torres <santiago@nyu.edu>,
	git@vger.kernel.org
Subject: Re: [PATCH] git-status.txt: mention --no-optional-locks
Date: Mon, 27 Nov 2017 15:07:43 +0900	[thread overview]
Message-ID: <xmqqindwcl00.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20171127060412.GA1247@sigill> (Jeff King's message of "Mon, 27 Nov 2017 01:04:12 -0500")

Jeff King <peff@peff.net> writes:

> On Mon, Nov 27, 2017 at 12:24:43AM -0500, Jeff King wrote:
>
>> > If people have to ask on the mailing list even after reading the man
>> > pages, that's a strong indicator that we could do better.
>> 
>> Sure. That's why I suggested improving the documentation in my last
>> email. But in all the discussion, I haven't seen any patch to that
>> effect.
>
> Maybe like this.

I gave it only a single read, and it was a quite easy read.

Will queue but not immediately merge to 'next' before I hear from
others.

Thanks.

> -- >8 --
> Subject: [PATCH] git-status.txt: mention --no-optional-locks
>
> If you come to the documentation thinking "I do not want Git
> to take any locks for my background processes", then you may
> easily run across "--no-optional-locks" in git.txt.
>
> But it's quite reasonable to hit a specific instance of the
> problem: you have "git status" running in the background,
> and you notice that it causes lock contention with other
> processes. So you look in git-status.txt to see if there is
> a way to disable it, but there's no mention of the flag.
>
> Let's add a short note mentioning that status does indeed
> touch the index (and why), with a pointer to the global
> option. That can point users in the right direction and help
> them make a more informed decision about what they're
> disabling.
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
>  Documentation/git-status.txt | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
> index fc282e0a92..81cab9aefb 100644
> --- a/Documentation/git-status.txt
> +++ b/Documentation/git-status.txt
> @@ -387,6 +387,19 @@ ignored submodules you can either use the --ignore-submodules=dirty command
>  line option or the 'git submodule summary' command, which shows a similar
>  output but does not honor these settings.
>  
> +BACKGROUND REFRESH
> +------------------
> +
> +By default, `git status` will automatically refresh the index, updating
> +the cached stat information from the working tree and writing out the
> +result. Writing out the updated index is an optimization that isn't
> +strictly necessary (`status` computes the values for itself, but writing
> +them out is just to save subsequent programs from repeating our
> +computation). When `status` is run in the background, the lock held
> +during the write may conflict with other simultaneous processes, causing
> +them to fail. Scripts running `status` in the background should consider
> +using `git --no-optional-locks status` (see linkgit:git[1] for details).
> +
>  SEE ALSO
>  --------
>  linkgit:gitignore[5]