git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: David Miller <davem@davemloft.net>
Cc: jonsmirl@gmail.com, peff@peff.net, nico@cam.org,
	dberlin@dberlin.org,         harvey.harrison@gmail.com,
	ismail@pardus.org.tr, gcc@gcc.gnu.org,
	        git@vger.kernel.org
Subject: Re: Git and GCC
Date: Fri, 7 Dec 2007 09:23:47 -0800 (PST)	[thread overview]
Message-ID: <alpine.LFD.0.9999.0712070919590.7274@woody.linux-foundation.org> (raw)
In-Reply-To: <20071207.045329.204650714.davem@davemloft.net>



On Fri, 7 Dec 2007, David Miller wrote:
> 
> Also I could end up being performance limited by SHA, it's not very
> well tuned on Sparc.  It's been on my TODO list to code up the crypto
> unit support for Niagara-2 in the kernel, then work with Herbert Xu on
> the userland interfaces to take advantage of that in things like
> libssl.  Even a better C/asm version would probably improve GIT
> performance a bit.

I doubt yu can use the hardware support. Kernel-only hw support is 
inherently broken for any sane user-space usage, the setup costs are just 
way way too high. To be useful, crypto engines need to support direct user 
space access (ie a regular instruction, with all state being held in 
normal registers that get saved/restored by the kernel).

> Is SHA a significant portion of the compute during these repacks?
> I should run oprofile...

SHA1 is almost totally insignificant on x86. It hardly shows up. But we 
have a good optimized version there.

zlib tends to be a lot more noticeable (especially the uncompression: it 
may be faster than compression, but it's done _so_ much more that it 
totally dominates).

			Linus

  reply	other threads:[~2007-12-07 17:25 UTC|newest]

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4aca3dc20712051108s216d3331t8061ef45b9aa324a@mail.gmail.com>
2007-12-06  2:28 ` Git and GCC 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  4:32           ` 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  6:47                     ` 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 18:02                             ` Nicolas Pitre
2007-12-07  6:50                               ` Jeff King
2007-12-07  7:27                                 ` Jeff King
2007-12-06 18:35                             ` Linus Torvalds
2007-12-06 18:55                               ` 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  0:47                               ` Harvey Harrison
2007-12-10  9:54                                 ` Gabriel Paubert
2007-12-10 15:35                                   ` Nicolas Pitre
2007-12-07  3:31                             ` David Miller
2007-12-07  6:38                               ` Jeff King
2007-12-07  7:10                                 ` Jon Smirl
2007-12-07 12:53                                   ` David Miller
2007-12-07 17:23                                     ` Linus Torvalds [this message]
2007-12-07 20:26                                       ` Giovanni Bajo
2007-12-07 22:14                                         ` Jakub Narebski
2007-12-07 23:04                                           ` Luke Lu
2007-12-07 23:14                                           ` Giovanni Bajo
2007-12-07 23:33                                             ` Daniel Berlin
2007-12-08 12:00                                               ` Johannes Schindelin
2007-12-08  1:55                                       ` David Miller
2007-12-10  9:57                                     ` David Miller
2007-12-06  6:09                 ` Linus Torvalds
2007-12-06  7:49                   ` Harvey Harrison
2007-12-06  8:11                     ` David Brown
2007-12-06 14:01                     ` Nicolas Pitre
2007-12-06 12:03                   ` [PATCH] gc --aggressive: make it really aggressive Johannes Schindelin
2007-12-06 13:42                     ` Theodore Tso
2007-12-06 14:15                       ` Nicolas Pitre
2007-12-06 14:22                     ` Pierre Habouzit
2007-12-06 15:55                       ` Johannes Schindelin
2007-12-06 17:05                         ` David Kastrup
2007-12-06 15:30                     ` Harvey Harrison
2007-12-06 15:56                       ` Johannes Schindelin
2007-12-06 16:19                       ` Linus Torvalds
2009-03-18 16:01                     ` Johannes Schindelin
2009-03-18 16:27                       ` Teemu Likonen
2009-03-18 18:02                       ` Nicolas Pitre
2007-12-06 18:04                   ` Git and GCC Daniel Berlin
2007-12-06 18:29                     ` Linus Torvalds
2007-12-07  2:42                     ` Harvey Harrison
2007-12-07  3:01                       ` Linus Torvalds
2007-12-07  4:06                         ` Jon Smirl
2007-12-07  4:21                           ` Nicolas Pitre
2007-12-07  5:21                           ` 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 18:45                     ` Linus Torvalds
2007-12-07  5:36                       ` NightStrike
2007-12-06 19:12                   ` Jon Loeliger
2007-12-06 19:39                     ` Linus Torvalds
2007-12-07  0:29                       ` Jakub Narebski
2007-12-06 20:04                     ` Junio C Hamano
2007-12-06 21:02                       ` Junio C Hamano
2007-12-06 22:26                         ` 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 11:57       ` Johannes Schindelin
2007-12-06 12:04         ` Ismail Dönmez
     [not found] ` <2007-12-05-21-23-14+trackit+sam@rfc1149.net>
     [not found]   ` <1196891451.10408.54.camel@brick>
     [not found]     ` <jeeje0ogvk.fsf@sykes.suse.de>
     [not found]       ` <1196897840.10408.57.camel@brick>
     [not found]         ` <38a0d8450712130640p1b5d74d6nfa124ad0b0110d64@mail.gmail.com>
     [not found]           ` <1197572755.898.15.camel@brick>
2007-12-17 22:15             ` "Argument list too long" in git remote update (Was: Git and GCC) Geert Bosch
2007-12-17 22:59               ` Johannes Schindelin
2007-12-17 23:01               ` Linus Torvalds
2007-12-18  1:34                 ` Derek Fawcus
2007-12-18  1:52                   ` Shawn O. Pearce
2007-12-08  2:21 Git and GCC J.C. Pizarro
2007-12-08 12:24 ` Johannes Schindelin
2007-12-08 19:53   ` Joe Buck
2007-12-08 20:28     ` Marco Costalba
2007-12-09  1:51       ` Daniel Berlin
2007-12-15  0:18   ` Nix

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.LFD.0.9999.0712070919590.7274@woody.linux-foundation.org \
    --to=torvalds@linux-foundation.org \
    --cc=davem@davemloft.net \
    --cc=dberlin@dberlin.org \
    --cc=gcc@gcc.gnu.org \
    --cc=git@vger.kernel.org \
    --cc=harvey.harrison@gmail.com \
    --cc=ismail@pardus.org.tr \
    --cc=jonsmirl@gmail.com \
    --cc=nico@cam.org \
    --cc=peff@peff.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).