linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Joel Becker <jlbec@evilplan.org>
To: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Jeff Garzik <jgarzik@mandrakesoft.com>,
	Andrew Morton <akpm@zip.com.au>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: fadvise syscall?
Date: Mon, 18 Mar 2002 08:05:31 +0000	[thread overview]
Message-ID: <20020318080531.W4836@parcelfarce.linux.theplanet.co.uk> (raw)
In-Reply-To: <3C945635.4050101@mandrakesoft.com> <3C945A5A.9673053F@zip.com.au> <3C945D7D.8040703@mandrakesoft.com> <5.1.0.14.2.20020317131910.0522b490@pop.cus.cam.ac.uk>

On Sun, Mar 17, 2002 at 01:41:37PM +0000, Anton Altaparmakov wrote:
> We don't need fadvise IMHO. That is what open(2) is for. The streaming 
> request you are asking for is just a normal open(2). It will do read ahead 
> which is perfect for streaming (of data size << RAM size in its current form).

	A quick real world example of where fadvise can work well.
Imagine a database appliction that doesn't use O_DIRECT (for whatever
reason, could even be that they don't trust the linux implementation yet
:-).  So, this database gets a query.  That query requires a full table
scan, so it calls fadvise(fd, F_SEQUENTIAL).  Then another query does
row-specific access, and caching helps.  So it wants to turn off
F_SEQUENTIAL.
	Other applications can use this sort of stuff.  DBM could, for
instance.  So might GIMP.  Etc.  Dynamic hints have real world
applications.


Joel


-- 

print STDOUT q
Just another Perl hacker,
unless $spring
	-Larry Wall

			http://www.jlbec.org/
			jlbec@evilplan.org

  parent reply	other threads:[~2002-03-18  8:05 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-03-17  8:39 fadvise syscall? Jeff Garzik
2002-03-17  8:56 ` Andrew Morton
2002-03-17  9:10   ` Jeff Garzik
2002-03-17 23:59     ` Anton Altaparmakov
2002-03-17 13:41   ` Anton Altaparmakov
2002-03-17 14:31     ` Simon Richter
2002-03-17 14:56       ` Jan Hudec
2002-03-17 15:00     ` Anton Altaparmakov
2002-03-17 19:20     ` Joel Becker
2002-03-18  7:28     ` Jeff Garzik
2002-03-18  7:55       ` Andrew Morton
2002-03-18  8:07         ` Jeff Garzik
2002-03-18  8:17           ` Andrew Morton
2002-03-18 16:41         ` Richard Gooch
2002-03-18 19:00           ` Andrew Morton
2002-03-18 19:15             ` Richard Gooch
2002-03-22 16:05       ` Pavel Machek
2002-03-24  6:38         ` Stevie O
2002-03-24 11:24           ` Pavel Machek
2002-03-24 12:52             ` Anton Altaparmakov
2002-03-25 11:12               ` Pavel Machek
2002-03-18  8:05     ` Joel Becker [this message]
2002-03-18  8:10       ` Jeff Garzik
2002-03-18  8:20         ` Joel Becker
2002-03-18  8:14       ` Andrew Morton
2002-03-18 14:39         ` Martin K. Petersen
2002-03-18 19:15           ` Andrew Morton
2002-03-18 19:42             ` Martin K. Petersen
2002-03-19 20:08               ` Eric W. Biederman
2002-03-19 23:38                 ` Martin K. Petersen
2002-03-17 20:18   ` Richard Gooch
2002-03-17 15:13 ` Ken Hirsch
2002-03-17 17:14 ` Anton Altaparmakov
2002-03-17 18:31   ` Mark Mielke
2002-03-17 18:35   ` Ken Hirsch
2002-03-17 19:06   ` Anton Altaparmakov
2002-03-17 20:19     ` Ken Hirsch
2002-03-18  0:12     ` Anton Altaparmakov
     [not found]       ` <a73ujs$5mc$1@cesium.transmeta.com>
2002-03-18  8:58         ` Jan Hudec
2002-03-18 10:08           ` Jeff Garzik
2002-03-18 17:29             ` Mark Mielke

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=20020318080531.W4836@parcelfarce.linux.theplanet.co.uk \
    --to=jlbec@evilplan.org \
    --cc=aia21@cam.ac.uk \
    --cc=akpm@zip.com.au \
    --cc=jgarzik@mandrakesoft.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /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).