From: Michael J Gruber <git@drmicha.warpmail.net>
To: Marat Radchenko <marat@slonopotamus.org>
Cc: git@vger.kernel.org
Subject: Re: What's the difference between `git show branch:file | diff -u - file` vs `git diff branch file`?
Date: Tue, 23 Aug 2011 12:03:28 +0200 [thread overview]
Message-ID: <4E537AF0.9070604@drmicha.warpmail.net> (raw)
In-Reply-To: <loom.20110823T091132-107@post.gmane.org>
Marat Radchenko venit, vidit, dixit 23.08.2011 09:25:
> $ time git show branch:file | diff -u - file > /dev/null
>
> real 0m0.003s
> user 0m0.000s
> sys 0m0.000s
>
> $ time git diff branch -- file > /dev/null
>
> real 0m31.442s
> user 0m31.040s
> sys 0m0.380s
>
> What does git diff do so it takes that much time? And is there any flag to git
> diff so that it will work as fast as show + diff? I thought these two are
> equivalent but from run time it is obvious that they aren't.
>
> gprof output: http://slonopotamus.org/git-diff/git-diff-branch.gprof.txt
>
Is that a very large tree or a very slow file system?
>From the gprof output, it would appear that we compare a lot of cache
entries (or rather: spent most time on...). Do we enumerate all
differing files and only then limit diff output by path??
Michael
next prev parent reply other threads:[~2011-08-23 10:03 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-23 7:25 What's the difference between `git show branch:file | diff -u - file` vs `git diff branch file`? Marat Radchenko
2011-08-23 10:03 ` Michael J Gruber [this message]
2011-08-23 10:52 ` Marat Radchenko
2011-08-23 15:20 ` Michael Witten
2011-08-23 15:34 ` Michael J Gruber
2011-08-23 16:45 ` Marat Radchenko
2011-08-23 17:15 ` Junio C Hamano
2011-08-23 18:21 ` Marat Radchenko
2011-08-23 20:07 ` Michael J Gruber
2011-08-25 16:09 ` Marat Radchenko
2011-08-25 21:10 ` Junio C Hamano
2011-08-26 9:43 ` Marat Radchenko
2011-08-29 7:41 ` Nguyen Thai Ngoc Duy
2011-08-29 14:48 ` Marat Radchenko
2011-08-29 16:09 ` Nguyen Thai Ngoc Duy
2011-08-29 17:18 ` Junio C Hamano
2011-08-29 20:42 ` Junio C Hamano
2011-08-29 20:50 ` Junio C Hamano
2011-08-29 21:09 ` Junio C Hamano
2011-08-29 21:33 ` [PATCH 0/3] Un-pessimize "diff-index $commit -- $pathspec" Junio C Hamano
2011-08-29 21:33 ` [PATCH 1/3] traverse_trees(): allow pruning with pathspec Junio C Hamano
2011-08-30 12:53 ` Nguyen Thai Ngoc Duy
2011-08-30 17:44 ` Junio C Hamano
2011-08-31 1:35 ` Nguyen Thai Ngoc Duy
2011-10-09 15:39 ` Michael Haggerty
2011-10-09 21:35 ` Nguyen Thai Ngoc Duy
2011-10-10 4:42 ` Michael Haggerty
2011-08-29 21:33 ` [PATCH 2/3] unpack-trees: " Junio C Hamano
2011-08-30 13:03 ` Nguyen Thai Ngoc Duy
2011-08-30 17:32 ` Junio C Hamano
2011-08-30 15:24 ` David Michael Barr
2011-08-29 21:33 ` [PATCH 3/3] diff-index: pass pathspec down to unpack-trees machinery Junio C Hamano
2012-01-11 6:31 ` Jonathan Nieder
2012-01-11 8:05 ` Junio C Hamano
2012-01-11 12:33 ` Nguyen Thai Ngoc Duy
2012-01-11 12:47 ` Nguyen Thai Ngoc Duy
2012-01-11 20:40 ` Junio C Hamano
2012-01-12 4:09 ` [PATCH] tree_entry_interesting: make recursive mode default Nguyễn Thái Ngọc Duy
2012-01-12 5:04 ` Junio C Hamano
2012-01-12 5:44 ` Nguyen Thai Ngoc Duy
2012-01-14 9:23 ` [PATCH v2 1/2] Document limited recursion pathspec matching with wildcards Nguyễn Thái Ngọc Duy
2012-01-14 9:23 ` [PATCH v2 2/2] tree_entry_interesting: make recursive mode default Nguyễn Thái Ngọc Duy
2012-01-15 3:12 ` Junio C Hamano
2012-01-15 10:03 ` Nguyen Thai Ngoc Duy
2012-01-16 22:15 ` Junio C Hamano
2012-01-18 8:59 ` Nguyen Thai Ngoc Duy
2012-01-15 2:38 ` [PATCH v2 1/2] Document limited recursion pathspec matching with wildcards Junio C Hamano
2012-01-15 9:48 ` Nguyen Thai Ngoc Duy
2011-08-29 21:56 ` [PATCH 0/3] Un-pessimize "diff-index $commit -- $pathspec" Linus Torvalds
2011-08-29 22:05 ` Junio C Hamano
2011-08-29 22:11 ` Linus Torvalds
2011-08-29 23:42 ` Junio C Hamano
2011-08-30 6:16 ` Marat Radchenko
2011-08-31 0:18 ` Junio C Hamano
2011-08-30 10:04 ` Michael J Gruber
2011-08-30 17:03 ` Junio C Hamano
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