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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Nicolas Pitre <nico@cam.org>
Cc: Chris Lee <clee@kde.org>, Junio C Hamano <junkio@cox.net>,
	Git Mailing List <git@vger.kernel.org>
Subject: Re: git-index-pack really does suck..
Date: Tue, 3 Apr 2007 16:29:08 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.64.0704031624090.6730@woody.linux-foundation.org> (raw)
In-Reply-To: <alpine.LFD.0.98.0704031836350.28181@xanadu.home>



On Tue, 3 Apr 2007, Nicolas Pitre wrote:
> 
> Are hard numbers like 7% overhead (because right now that's all we have) 
> really worth it against bad _perceptions_?

If it actually stays at just 7% even with large repos (and the numbers 
from Chris seem to say that it doesn't get worse - in fact, it may be that 
the lookup gets relatively more efficient for a large repo thanks to the 
log(n) costs), I agree that 7% probably isn't worth worrying about when 
weighed against "guaranteed no SHA1 collision". Especially as long as 
you'd normally only hit it when your real performance issue is going to be 
the network.

So especially if we can make sure that the *local* case is ok, where the 
network isn't going to be the bottleneck, I think we can/should do the 
paranoia.

That's especially true as it is also the local case where the 7% has 
already been shown to be just the best case, with the worst case being 
many hundred percent (and memory use going up from 55M to 280M in one 
example), thanks to us actually *finding* the objects.

			Linus

  parent reply	other threads:[~2007-04-03 23:30 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-03 15:15 git-index-pack really does suck Linus Torvalds
     [not found] ` <Pi ne.LNX.4.64.0704031413200.6730@woody.linux-foundation.org>
     [not found]   ` <alpine.LFD.0.98. 0704031836350.28181@xanadu.home>
     [not found] ` <db 69205d0704031227q1009eabfhdd82aa3636f25bb6@mail.gmail.com>
     [not found]   ` <Pine.LNX.4.64.07 04031304420.6730@woody.linux-foundation.org>
     [not found]     ` <Pine.LNX.4.64.0704031322490.67 30@woody.linux-foundation.org>
2007-04-03 16:21 ` Linus Torvalds
2007-04-03 16:40   ` Nicolas Pitre
2007-04-03 16:33 ` Nicolas Pitre
2007-04-03 19:27 ` Chris Lee
2007-04-03 19:49   ` Nicolas Pitre
2007-04-03 19:54     ` Chris Lee
2007-04-03 20:18   ` Linus Torvalds
2007-04-03 20:32     ` Nicolas Pitre
2007-04-03 20:40       ` Junio C Hamano
2007-04-03 21:00         ` Linus Torvalds
2007-04-03 21:28           ` Nicolas Pitre
2007-04-03 22:49           ` Chris Lee
2007-04-03 23:12             ` Linus Torvalds
2007-04-03 20:56       ` Linus Torvalds
2007-04-03 21:03         ` Shawn O. Pearce
2007-04-03 21:13           ` Linus Torvalds
2007-04-03 21:17             ` Shawn O. Pearce
2007-04-03 21:26               ` Linus Torvalds
2007-04-03 21:28                 ` Linus Torvalds
2007-04-03 22:31                   ` Junio C Hamano
2007-04-03 22:38                     ` Shawn O. Pearce
2007-04-03 22:41                       ` Junio C Hamano
2007-04-05 10:22                   ` [PATCH 1/2] git-fetch--tool pick-rref Junio C Hamano
2007-04-05 10:22                   ` [PATCH 2/2] git-fetch: use fetch--tool pick-rref to avoid local fetch from alternate Junio C Hamano
2007-04-05 16:15                     ` Shawn O. Pearce
2007-04-05 21:37                       ` Junio C Hamano
2007-04-03 21:34               ` git-index-pack really does suck Nicolas Pitre
2007-04-03 21:37                 ` Shawn O. Pearce
2007-04-03 21:44                   ` Junio C Hamano
2007-04-03 21:53                     ` Shawn O. Pearce
2007-04-03 22:10                       ` Jeff King
2007-04-03 22:40                 ` Dana How
2007-04-03 22:52                   ` Linus Torvalds
2007-04-03 22:31                     ` David Lang
2007-04-03 23:00                   ` Nicolas Pitre
2007-04-03 21:21         ` Nicolas Pitre
2007-04-03 20:33     ` Linus Torvalds
2007-04-03 21:05       ` Nicolas Pitre
2007-04-03 21:11         ` Shawn O. Pearce
2007-04-03 21:24         ` Linus Torvalds
     [not found]           ` <alpine.LF D.0.98.0704031735470.28181@xanadu.home>
2007-04-03 21:42           ` Nicolas Pitre
2007-04-03 22:07             ` Junio C Hamano
2007-04-03 22:11               ` Shawn O. Pearce
2007-04-03 22:34               ` Nicolas Pitre
2007-04-03 22:14             ` Linus Torvalds
2007-04-03 22:55               ` Nicolas Pitre
2007-04-03 22:36                 ` David Lang
2007-04-04  9:51                   ` Alex Riesen
     [not found]                     ` <P ine.LNX.4.63.0704061455380.24050@qynat.qvtvafvgr.pbz>
2007-04-06 21:56                     ` David Lang
2007-04-06 22:47                       ` Junio C Hamano
2007-04-06 22:49                         ` Junio C Hamano
2007-04-06 22:22                           ` David Lang
2007-04-06 22:55                             ` Junio C Hamano
2007-04-06 22:28                               ` David Lang
2007-04-03 23:29                 ` Linus Torvalds [this message]
2007-04-03 20:34     ` Junio C Hamano
2007-04-03 20:53       ` Nicolas Pitre

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