From: Linus Torvalds <torvalds@osdl.org>
To: Josh Triplett <josh@freedesktop.org>
Cc: Junio C Hamano <junkio@cox.net>, git@vger.kernel.org
Subject: Re: [RFC] git-split: Split the history of a git repository by subdirectories and ranges
Date: Mon, 23 Oct 2006 14:06:49 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.64.0610231402560.3962@g5.osdl.org> (raw)
In-Reply-To: <453D2B98.8010903@freedesktop.org>
On Mon, 23 Oct 2006, Josh Triplett wrote:
>
> Or have I misunderstood the case you have concerns about? Why would the
> "nice" format incur additional cost?
Try it. The default "extreme" simplification is a _hell_ of a lot faster
than doing the full history.
[torvalds@g5 linux]$ time git-rev-list --full-history --parents HEAD -- kernel/sched.c >/dev/null
real 0m4.660s
user 0m4.612s
sys 0m0.044s
[torvalds@g5 linux]$ time git-rev-list --parents HEAD -- kernel/sched.c >/dev/null
real 0m1.684s
user 0m1.680s
sys 0m0.004s
and the "nice" thing will be much slower still: just trying to figure out
whether a commit is a parent of another commit is expensive. Doing so for
_each_ merge is more expensive still. I think it's O(n^3), but what do I
know..
Linus
next prev parent reply other threads:[~2006-10-23 21:07 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-27 8:05 [RFC] git-split: Split the history of a git repository by subdirectories and ranges Josh Triplett
2006-09-27 10:13 ` Junio C Hamano
2006-09-27 11:59 ` Andy Whitcroft
2006-09-27 19:08 ` Junio C Hamano
2006-09-27 19:31 ` Junio C Hamano
2006-10-23 10:17 ` Josh Triplett
2006-10-23 15:52 ` Linus Torvalds
2006-10-23 19:27 ` Josh Triplett
2006-10-23 19:50 ` Linus Torvalds
2006-10-23 20:07 ` Jakub Narebski
2006-10-23 20:52 ` Josh Triplett
2006-10-23 21:06 ` Linus Torvalds [this message]
2006-10-23 21:19 ` Linus Torvalds
2006-10-24 14:56 ` Johannes Schindelin
2006-10-24 15:19 ` Linus Torvalds
2006-10-25 0:10 ` Junio C Hamano
2006-10-25 0:19 ` Jakub Narebski
2006-10-25 1:59 ` Josh Triplett
2006-10-25 2:13 ` Junio C Hamano
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