From: Joachim B Haga <cjhaga@fys•uio.no>
To: git@vger•kernel.org
Subject: Re: Some git performance measurements..
Date: Sat, 01 Dec 2007 12:36:04 +0100 [thread overview]
Message-ID: <85abou8x5n.fsf@lupus.ig3.net> (raw)
In-Reply-To: alpine.LFD.0.9999.0711281852160.8458@woody.linux-foundation.org
Linus Torvalds <torvalds@linux-foundation•org> writes:
> The pack-files (both index and data) are accessed somewhat randomly, but
> there is still enough locality that doing read-ahead and clustering really
> does help.
They are dense enough that slurping them in whole is 20% faster, at
least here. And much less noisy! These are both cache-cold tests.
$ time git read-tree -m -u HEAD HEAD
real 0m9.255s
user 0m0.832s
sys 0m0.196s
$ time (cat .git/objects/pack/* .git/index >/dev/null; git read-tree -m -u HEAD HEAD)
real 0m7.141s
user 0m0.936s
sys 0m1.912s
Now, I don't know how useful this is since git doesn't know if the
data are cached. Is it perhaps possible to give a hint to the
readahead logic that it should try to read as far as possible?
-j.
next prev parent reply other threads:[~2007-12-01 11:36 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-29 2:49 Some git performance measurements Linus Torvalds
2007-11-29 3:14 ` Linus Torvalds
2007-11-29 3:59 ` Nicolas Pitre
2007-11-29 4:32 ` Linus Torvalds
2007-11-29 17:25 ` Nicolas Pitre
2007-11-29 17:48 ` Linus Torvalds
2007-11-29 18:52 ` Nicolas Pitre
2007-11-30 5:00 ` Junio C Hamano
2007-11-30 6:03 ` Linus Torvalds
2007-11-30 0:54 ` Jakub Narebski
2007-11-30 2:21 ` Linus Torvalds
2007-11-30 2:39 ` Jakub Narebski
2007-11-30 2:40 ` Nicolas Pitre
2007-11-30 6:11 ` Steffen Prohaska
2007-12-07 13:35 ` Mike Ralphson
2007-12-07 13:49 ` Johannes Schindelin
2007-12-07 16:07 ` Linus Torvalds
2007-12-07 16:09 ` Mike Ralphson
2007-12-07 18:37 ` Johannes Schindelin
2007-12-07 19:15 ` Mike Ralphson
2007-12-08 11:05 ` Johannes Schindelin
2007-12-08 23:04 ` Brian Downing
2007-11-30 2:54 ` Linus Torvalds
2007-12-05 1:04 ` Federico Mena Quintero
2007-12-01 11:36 ` Joachim B Haga [this message]
2007-12-01 17:19 ` Linus Torvalds
2007-11-29 5:17 ` Junio C Hamano
2007-11-29 10:17 ` [PATCH] per-directory-exclude: lazily read .gitignore files Junio C Hamano
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