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From: Jeff King <peff@peff.net>
To: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Patrick Steinhardt <ps@pks.im>, git@vger.kernel.org
Subject: Re: [PATCH 7/8] receive-pack: skip connectivity checks on delete-only commands
Date: Thu, 27 May 2021 10:38:45 -0400	[thread overview]
Message-ID: <YK+u9SWQrnJe51Gq@coredump.intra.peff.net> (raw)
In-Reply-To: <60a801bdd1b4b_5580620828@natae.notmuch>

On Fri, May 21, 2021 at 01:53:49PM -0500, Felipe Contreras wrote:

> Patrick Steinhardt wrote:
> > In the case where git-receive-pack(1) receives only commands which
> > delete references, then per technical specification the client MUST NOT
> > send a packfile. As a result, we know that no new objects have been
> > received, which makes it a moot point to check whether all received
> > objects are fully connected.
> 
> I don't know if this is related but yesterday I decided to delete a
> bunch of refs from a forked repo in GitHub. I did it naively with a for
> loop and so it was doing a bunch of `git push myrepo :ref`.
> 
> It was unbearably slow.
> 
> Sure, it was a stupid thing to do, but maybe it can help you do some
> tests.

Patrick's patch might help some, as it would avoid calling rev-list at
all. But we wouldn't do any traversal in that command if there are no
positive tips anyway, so it is really just saving the startup overhead
of iterating the ref tips to add them to the traversal.

In the case of GitHub, the problem is much more likely outside of Git's
immediate control. Every push will run GitHub-specific hooks for things
like branch protections, etc, and there's a lot of overhead there.

-Peff

  reply	other threads:[~2021-05-27 14:38 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-19 19:13 [PATCH 0/8] Speed up connectivity checks via quarantine dir Patrick Steinhardt
2021-05-19 19:13 ` [PATCH 1/8] perf: fix when running with TEST_OUTPUT_DIRECTORY Patrick Steinhardt
2021-05-20  2:03   ` Chris Torek
2021-05-19 19:13 ` [PATCH 2/8] p5400: add perf tests for git-receive-pack(1) Patrick Steinhardt
2021-05-20  2:09   ` Chris Torek
2021-05-20 17:04   ` Jeff King
2021-05-21 15:03   ` SZEDER Gábor
2021-05-19 19:13 ` [PATCH 3/8] tmp-objdir: expose function to retrieve path Patrick Steinhardt
2021-05-20  0:16   ` Elijah Newren
2021-05-19 19:13 ` [PATCH 4/8] packfile: have `for_each_file_in_pack_dir()` return error codes Patrick Steinhardt
2021-05-19 19:13 ` [PATCH 5/8] object-file: allow reading loose objects without reading their contents Patrick Steinhardt
2021-05-19 19:13 ` [PATCH 6/8] connected: implement connectivity check via temporary object dirs Patrick Steinhardt
2021-05-19 19:13 ` [PATCH 7/8] receive-pack: skip connectivity checks on delete-only commands Patrick Steinhardt
2021-05-21 18:53   ` Felipe Contreras
2021-05-27 14:38     ` Jeff King [this message]
2021-05-19 19:13 ` [PATCH 8/8] receive-pack: check connectivity via quarantined objects Patrick Steinhardt
2021-05-20  2:19 ` [PATCH 0/8] Speed up connectivity checks via quarantine dir Chris Torek
2021-05-20 16:50 ` Jeff King
2021-05-20 21:45   ` Junio C Hamano
2021-05-21  9:30     ` Jeff King
2021-05-21  9:42   ` Patrick Steinhardt
2021-05-21 11:20   ` Ævar Arnfjörð Bjarmason

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