linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jens Axboe <axboe@suse.de>
To: Greg Stark <gsstark@mit.edu>, Erik Steffl <steffl@bigfoot.com>,
	linux-kernel@vger.kernel.org
Subject: Re: libata in 2.4.24?
Date: Thu, 4 Dec 2003 09:18:40 +0100	[thread overview]
Message-ID: <20031204081840.GB1086@suse.de> (raw)
In-Reply-To: <20031202174048.GQ1566@mis-mike-wstn.matchmail.com>

On Tue, Dec 02 2003, Mike Fedyk wrote:
> On Tue, Dec 02, 2003 at 11:31:45AM -0500, Greg Stark wrote:
> > 
> > Mike Fedyk <mfedyk@matchmail.com> writes:
> > 
> > > > Libata, uses the scsi system instead of the existing ide layer because many
> > > > new sata controllers are using an interface that is very similair to scsi
> > > > (much like atapi).
> > 
> > Now I have a different question. Does the scsi-like SATA interface include tcq?
> > 
> > Because one of the long-standing issues with IDE drives and Postgres is the
> > fact that even after issuing an fsync the data may be sitting in the drive's
> > buffer. This doesn't happen with SCSI because the drives aren't forced to lie
> > about the data being on disk in order to handle subsequent requests. Turning
> > off write-caching on IDE drives absolutely destroys performance.
> 
> There are PATA drives that do TCQ too, but you have to look for that feature
> specifically.  IDE TCQ is in 2.6, but is still experemental.  I think Jens
> Axboe was the one working on it IIRC.  He would have more details.

Yes that was me. PATA TCQ is currently disabled in the 2.6 kernel
configs, and it will most likely just go away sometime soonish. It's not
a very useful feature, PATA TCQ is pretty broken. I knew this from the
beginning, but thought that it would be fun to try it in real life. It's
just not worth it, though.

SATA host queueing support will be useful.

-- 
Jens Axboe


  parent reply	other threads:[~2003-12-04  8:18 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-11-28 18:27 linux-2.4.23 released Marcelo Tosatti
2003-11-28 19:06 ` Willy Tarreau
2003-11-28 22:55 ` J.A. Magallon
2003-11-29 22:26 ` libata in 2.4.24? Samuel Flory
2003-11-29 23:10   ` Marcelo Tosatti
2003-12-01 10:43     ` Marcelo Tosatti
2003-12-01 18:06       ` Samuel Flory
2003-12-01 21:12         ` Greg Stark
2003-12-01 21:23           ` Samuel Flory
2003-12-01 21:44             ` Greg Stark
2003-12-01 22:00               ` Jeff Garzik
2003-12-01 22:06               ` Samuel Flory
2003-12-01 22:00             ` Erik Steffl
2003-12-02  5:36               ` Greg Stark
     [not found]                 ` <20031202055336.GO1566@mis-mike-wstn.matchmail.com>
2003-12-02  5:58                   ` Mike Fedyk
2003-12-02 16:31                     ` Greg Stark
2003-12-02 17:40                       ` Mike Fedyk
2003-12-02 18:04                         ` Jeff Garzik
2003-12-02 18:46                           ` Mike Fedyk
2003-12-02 18:49                             ` Jeff Garzik
2003-12-04  8:18                         ` Jens Axboe [this message]
2003-12-02 18:02                       ` Jeff Garzik
2003-12-02 18:51                         ` Greg Stark
2003-12-02 19:06                           ` Jeff Garzik
2003-12-02 20:10                             ` Greg Stark
2003-12-02 20:16                               ` Jeff Garzik
2003-12-02 20:34                                 ` Greg Stark
2003-12-02 22:34                               ` bill davidsen
2003-12-02 23:02                                 ` Mike Fedyk
2003-12-02 23:18                                   ` bill davidsen
2003-12-02 23:40                                     ` Mike Fedyk
2003-12-03  0:01                                     ` Jeff Garzik
2003-12-03  0:47                                 ` Jamie Lokier
2003-12-07  5:33                                   ` Bill Davidsen
2003-12-01 21:36           ` Justin Cormack
2003-12-01 13:41 Xose Vazquez Perez
2003-12-01 14:11 ` Marcelo Tosatti
2003-12-02 19:59   ` Stephan von Krawczynski
2003-12-02 22:05   ` bill davidsen
2003-12-02 22:34     ` Jeff Garzik
2003-12-03  0:34 Xose Vazquez Perez

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

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

  git send-email \
    --in-reply-to=20031204081840.GB1086@suse.de \
    --to=axboe@suse.de \
    --cc=gsstark@mit.edu \
    --cc=linux-kernel@vger.kernel.org \
    --cc=steffl@bigfoot.com \
    /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.
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 NNTP newsgroup(s).