From: "Jon Smirl" <jonsmirl@gmail.com>
To: "Linus Torvalds" <torvalds@linux-foundation.org>
Cc: "Harvey Harrison" <harvey.harrison@gmail.com>,
"Daniel Berlin" <dberlin@dberlin.org>,
"David Miller" <davem@davemloft.net>,
ismail@pardus.org.tr, gcc@gcc.gnu.org, git@vger.kernel.org
Subject: Re: Git and GCC
Date: Fri, 07 Dec 2007 15:01:00 -0000 [thread overview]
Message-ID: <9e4733910712062006l651571f3w7f76ce64c6650dff@mail.gmail.com> (raw)
In-Reply-To: <alpine.LFD.0.9999.0712061857060.13796@woody.linux-foundation.org>
On 12/6/07, Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
>
> On Thu, 6 Dec 2007, Harvey Harrison wrote:
> >
> > I've updated the public mirror repo with the very-packed version.
>
> Side note: it might be interesting to compare timings for
> history-intensive stuff with and without this kind of very-packed
> situation.
>
> The very density of a smaller pack-file might be enough to overcome the
> downsides (more CPU time to apply longer delta-chains), but regardless,
> real numbers talks, bullshit walks. So wouldn't it be nice to have real
> numbers?
>
> One easy way to get real numbers for history would be to just time some
> reasonably costly operation that uses lots of history. Ie just do a
>
> time git blame -C gcc/regclass.c > /dev/null
>
> and see if the deeper delta chains are very expensive.
jonsmirl@terra:/video/gcc$ time git blame -C gcc/regclass.c > /dev/null
real 1m21.967s
user 1m21.329s
sys 0m0.640s
The Mozilla repo is at least 50% larger than the gcc one. It took me
23 minutes to repack the gcc one on my $800 Dell. The trick to this is
lots of RAM and 64b. There is little disk IO during the compression
phase, everything is cached.
I have a 4.8GB git process with 4GB of physical memory. Everything
started slowing down a lot when the process got that big. Does git
really need 4.8GB to repack? I could only keep 3.4GB resident. Luckily
this happen at 95% completion. With 8GB of memory you should be able
to do this repack in under 20 minutes.
jonsmirl@terra:/video/gcc$ time git repack -a -d -f --depth=250 --window=250
real 22m54.380s
user 69m18.948s
sys 0m23.773s
> (Yeah, the above is pretty much designed to be the worst possible case for
> this kind of aggressive history packing, but I don't know if that choice
> of file to try to annotate is a good choice or not. I suspect that "git
> blame -C" with a CVS import is just horrid, because CVS commits tend to be
> pretty big and nasty and not as localized as we've tried to make things in
> the kernel, so doing the code copy detection is probably horrendously
> expensive)
>
> Linus
> -
> To unsubscribe from this list: send the line "unsubscribe git" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Jon Smirl
jonsmirl@gmail.com
next prev parent reply other threads:[~2007-12-07 15:01 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-05 19:08 Daniel Berlin
2007-12-05 19:11 ` Daniel Berlin
2007-12-05 19:13 ` NightStrike
2007-12-05 19:16 ` Daniel Berlin
2007-12-05 19:36 ` Ollie Wild
2007-12-05 21:40 ` Daniel Berlin
2007-12-06 0:01 ` Ollie Wild
2007-12-05 19:36 ` Ismail Dönmez
2007-12-05 20:23 ` Samuel Tardieu
2007-12-05 21:48 ` Daniel Berlin
2007-12-05 21:56 ` NightStrike
2007-12-06 18:15 ` Ian Lance Taylor
2007-12-06 19:29 ` Vincent Lefevre
2007-12-06 19:31 ` Ismail Dönmez
2007-12-06 20:35 ` Andrey Belevantsev
2007-12-06 20:43 ` Daniel Berlin
2007-12-05 21:50 ` Harvey Harrison
2007-12-05 23:34 ` Andreas Schwab
2007-12-05 23:37 ` Harvey Harrison
2007-12-13 16:30 ` Rafael Espindola
2007-12-13 20:31 ` Harvey Harrison
2007-12-06 2:28 ` David Miller
2007-12-06 2:41 ` Daniel Berlin
2007-12-06 2:52 ` David Miller
2007-12-06 3:47 ` Daniel Berlin
2007-12-06 4:20 ` David Miller
2007-12-06 4:28 ` Harvey Harrison
2007-12-06 4:33 ` Daniel Berlin
2007-12-06 4:48 ` David Miller
2007-12-06 5:11 ` Daniel Berlin
2007-12-06 5:15 ` Harvey Harrison
2007-12-06 5:17 ` Daniel Berlin
2007-12-06 6:48 ` Jon Smirl
2007-12-06 7:15 ` Jeff King
2007-12-06 14:18 ` Nicolas Pitre
2007-12-06 17:39 ` Jeff King
2007-12-06 18:03 ` Nicolas Pitre
2007-12-07 6:50 ` Jeff King
2007-12-07 7:27 ` Jeff King
2007-12-06 18:36 ` Linus Torvalds
2007-12-06 18:56 ` Jon Smirl
2007-12-06 19:08 ` Nicolas Pitre
2007-12-06 21:39 ` Jon Smirl
2007-12-06 22:08 ` Nicolas Pitre
2007-12-06 22:11 ` Jon Smirl
2007-12-06 22:22 ` Jon Smirl
2007-12-06 22:30 ` Nicolas Pitre
2007-12-06 22:44 ` Jon Smirl
2007-12-07 7:31 ` Jeff King
2007-12-08 1:49 ` Harvey Harrison
2007-12-10 9:57 ` Gabriel Paubert
2007-12-10 16:09 ` Nicolas Pitre
2007-12-07 3:31 ` David Miller
2007-12-07 6:39 ` Jeff King
2007-12-07 7:11 ` Jon Smirl
2007-12-07 12:53 ` David Miller
2007-12-07 17:24 ` Linus Torvalds
2007-12-07 20:27 ` Giovanni Bajo
2007-12-07 20:49 ` Giovanni Bajo
2007-12-07 22:33 ` Jakub Narebski
2007-12-07 23:14 ` Luke Lu
2007-12-07 23:33 ` Giovanni Bajo
2007-12-08 0:47 ` Daniel Berlin
2007-12-08 12:24 ` Johannes Schindelin
2007-12-08 2:21 ` David Miller
2007-12-10 10:15 ` David Miller
2007-12-06 6:09 ` Linus Torvalds
2007-12-06 7:49 ` Harvey Harrison
2007-12-06 8:12 ` David Brown
2007-12-06 14:02 ` Nicolas Pitre
2007-12-06 12:04 ` [PATCH] gc --aggressive: make it really aggressive Johannes Schindelin
2007-12-06 13:43 ` Theodore Tso
2007-12-06 14:15 ` Nicolas Pitre
2007-12-06 14:23 ` Pierre Habouzit
2007-12-06 15:56 ` Johannes Schindelin
2007-12-06 17:08 ` David Kastrup
2007-12-06 15:31 ` Harvey Harrison
2007-12-06 15:56 ` Johannes Schindelin
2007-12-06 16:19 ` Linus Torvalds
2007-12-06 18:05 ` Git and GCC Daniel Berlin
2007-12-06 18:29 ` Linus Torvalds
2007-12-07 2:42 ` Harvey Harrison
2007-12-07 15:01 ` Linus Torvalds
2007-12-07 15:01 ` Jon Smirl [this message]
2007-12-07 4:21 ` Nicolas Pitre
2007-12-07 5:22 ` Linus Torvalds
2007-12-07 7:08 ` Jon Smirl
2007-12-07 19:36 ` Nicolas Pitre
2007-12-06 18:24 ` NightStrike
2007-12-06 18:46 ` Linus Torvalds
2007-12-07 5:37 ` NightStrike
2007-12-06 19:13 ` Jon Loeliger
2007-12-06 19:40 ` Linus Torvalds
2007-12-07 0:30 ` Jakub Narebski
2007-12-06 20:04 ` Junio C Hamano
2007-12-06 21:02 ` Junio C Hamano
2007-12-06 22:25 ` David Kastrup
2007-12-06 22:38 ` [OT] " Randy Dunlap
2007-12-06 4:25 ` Harvey Harrison
2007-12-06 4:54 ` Linus Torvalds
2007-12-06 5:04 ` Harvey Harrison
2007-12-06 9:52 ` Andreas Schwab
2007-12-06 12:23 ` Harvey Harrison
2007-12-06 11:57 ` Johannes Schindelin
2007-12-06 12:04 ` Ismail Dönmez
2007-12-05 22:51 J.C. Pizarro
2007-12-08 3:51 J.C. Pizarro
2007-12-08 15:06 ` Johannes Schindelin
2007-12-08 20:28 ` Joe Buck
2007-12-08 20:49 ` Marco Costalba
2007-12-09 7:02 ` Daniel Berlin
2007-12-15 4:12 ` Nix
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