vc-git slows Emacs down quite a bit, trying to find a way to remove hooks

vc-git slows Emacs down quite a bit, trying to find a way to remove hooks

[Wei Liu]

Hi all

I find that vc-git takes quite a lot of time to load, both in Emacs 23
and Emacs snapshot. On my dev machine it takes up to 21 seconds. :-(

I don't want to disable vc-mode entirely, I just want to make sure
that vc-git doesn' t get loaded when I don't need it.

There was a topic [0] on this issue on stackoverflow. I took the
advice to remove vc-find-file-hook from fine-file-hook list, thus
speeding up Emacs a lot. But when I save file, vc-git gets loaded once
again, which consumes 21 seconds. So my questions are a) how to
disable this save file hook (I grepped in vc-*.el, didn't find
save-*-hook), b) are there any other hooks I need to take care of?

Extra questions (to developers and/or Emacs gurus): Why is vc-git so
slow (see [0] for profiling details)? Is there a genuine way to fix
this?

My setup: Intel Q9450, 4GB Ram, 500GB 7200rpm disk. Was playing with
Linux kernel git repository, which was stored in local disk.



Thanks
Wei.

[0] http://stackoverflow.com/questions/6724471/git-slows-down-emacs-to-death-how-to-fix-this

Re: vc-git slows Emacs down quite a bit, trying to find a way to remove hooks

[XeCycle]

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Wei Liu <liuw@liuw.name> writes:

> Hi all

Hello.

> I find that vc-git takes quite a lot of time to load, both in Emacs 23
> and Emacs snapshot. On my dev machine it takes up to 21 seconds. :-(
>
> I don't want to disable vc-mode entirely, I just want to make sure
> that vc-git doesn' t get loaded when I don't need it.

See variable vc-handled-backends.

If you need it sometimes, just set the variable temporarily back,
e.g. using directory-local variables.

> There was a topic [0] on this issue on stackoverflow. I took the
> advice to remove vc-find-file-hook from fine-file-hook list, thus
> speeding up Emacs a lot. But when I save file, vc-git gets loaded once
> again, which consumes 21 seconds. So my questions are a) how to
> disable this save file hook (I grepped in vc-*.el, didn't find
> save-*-hook), b) are there any other hooks I need to take care of?

a) Probably don't need that.  b) Same as a.

> Extra questions (to developers and/or Emacs gurus): Why is vc-git so
> slow (see [0] for profiling details)? Is there a genuine way to fix
> this?

Dunno, when viewing my local Emacs repo it isn't slow.  I don't
want to clone the kernel repo though.

-- 
Carl Lei (XeCycle)
Department of Physics, Shanghai Jiao Tong University
OpenPGP public key: 7795E591
Fingerprint: 1FB6 7F1F D45D F681 C845 27F7 8D71 8EC4 7795 E591

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Re: vc-git slows Emacs down quite a bit, trying to find a way to remove hooks

[Alex Bennee]

On 27 March 2012 03:05, XeCycle <XeCycle@gmail.com> wrote:
> Wei Liu <liuw@liuw.name> writes:
>
>> Hi all
>
> Hello.
>
>> I find that vc-git takes quite a lot of time to load, both in Emacs 23
>> and Emacs snapshot. On my dev machine it takes up to 21 seconds. :-(
>>
>> I don't want to disable vc-mode entirely, I just want to make sure
>> that vc-git doesn' t get loaded when I don't need it.
>
> See variable vc-handled-backends.

I'm using :

  (setq vc-handled-backends (remq 'Git vc-handled-backends))

But something keeps re-adding it and I can't find out what...

-- 
Alex, homepage: http://www.bennee.com/~alex/
http://www.half-llama.co.uk

Re: vc-git slows Emacs down quite a bit, trying to find a way to remove hooks

[XeCycle]

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Alex Bennee <kernel-hacker@bennee.com> writes:

[...]

> I'm using :
>
>   (setq vc-handled-backends (remq 'Git vc-handled-backends))
>
> But something keeps re-adding it and I can't find out what...

Try to reproduce with -q, if you can't, bisect your configuration
file.

-- 
Carl Lei (XeCycle)
Department of Physics, Shanghai Jiao Tong University
OpenPGP public key: 7795E591
Fingerprint: 1FB6 7F1F D45D F681 C845 27F7 8D71 8EC4 7795 E591

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