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From: Jeff King <peff@peff.net>
To: Peter Krefting <peter@softwolves.pp.se>
Cc: Git Mailing List <git@vger.kernel.org>
Subject: Re: cherry-pick very slow on big repository
Date: Fri, 10 Nov 2017 10:20:12 +0000	[thread overview]
Message-ID: <20171110102011.yqtka6a3wmgcvkl6@sigill.intra.peff.net> (raw)
In-Reply-To: <alpine.DEB.2.00.1711100959300.2391@ds9.cixit.se>

On Fri, Nov 10, 2017 at 10:39:39AM +0100, Peter Krefting wrote:

> Running strace, it seems like it is doing lstat(), open(), mmap(), close()
> and munmap() on every single file in the repository, which takes a lot of
> time.
> 
> I thought it was just updating the status, but "git status" returns
> immediately, while cherry-picking takes several minutes for every
> cherry-pick I do.

It kind of sounds like a temporary index is being refreshed that doesn't
have the proper stat information.

Can you get a backtrace? I'd do something like:

  - gdb --args git cherry-pick ...
  - 'r' to run
  - give it a few seconds to hit the CPU heavy part, then ^C
  - 'bt' to generate the backtrace

which should give a sense of which code path is leading to the slowdown
(or of course use real profiling tools, but if the slow path is taking 6
minutes, you'll be likely to stop in the middle of it ;) ).

-Peff

  reply	other threads:[~2017-11-10 10:20 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-10  9:39 cherry-pick very slow on big repository Peter Krefting
2017-11-10 10:20 ` Jeff King [this message]
2017-11-10 12:37   ` Peter Krefting
2017-11-10 12:59     ` Derrick Stolee
2017-11-10 14:05       ` Peter Krefting
2017-11-10 17:04         ` Kevin Willford
2017-11-13 11:19           ` Peter Krefting
2017-11-10 17:37         ` Elijah Newren
2017-11-10 23:32         ` Elijah Newren
2017-11-13 11:22           ` Peter Krefting
2017-11-13 18:09             ` Elijah Newren
2017-11-21 12:07               ` Peter Krefting
2017-11-21 17:14                 ` Elijah Newren

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