From: Mark Lord <lkml@rtr.ca>
To: Marr <marr@flex.com>
Cc: Linda Walsh <lkml@tlinx.org>, Bill Davidsen <davidsen@tmr.com>,
linux-kernel@vger.kernel.org, reiserfs-dev@namesys.com,
Andrew Morton <akpm@osdl.org>
Subject: Re: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?)
Date: Sun, 12 Mar 2006 17:15:06 -0500 [thread overview]
Message-ID: <44149D6A.7080005@rtr.ca> (raw)
In-Reply-To: <200603121653.30288.marr@flex.com>
Marr wrote:
>
> I tried turning 'readahead' off entirely ('hdparm -A0 /dev/hda') and, although
No, that should be "hdparm -a0 /dev/hda" (lowercase "-a").
And the same "-a" for all of your other test variants.
If you did it all with "-A", then the results are invalid,
and need to be redone.
The hdparm manpage explains this, but in a nutshell, "-A" is the
low-level drive firmware "look-ahead" mechanism, whereas "-a" is
the Linux kernel "read-ahead" scheme.
In general, most uppercase hdparm flags are drive *firmware* settings.
Cheers
next prev parent reply other threads:[~2006-03-12 22:15 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-02-24 20:22 Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change? Marr
2006-02-25 5:16 ` Andrew Morton
2006-02-26 13:07 ` Ingo Oeser
2006-02-26 13:50 ` Nick Piggin
2006-02-26 14:11 ` Arjan van de Ven
2006-02-27 20:52 ` Hans Reiser
2006-02-28 0:34 ` Nick Piggin
2006-02-28 18:42 ` Hans Reiser
2006-02-28 18:51 ` Hans Reiser
2006-02-27 20:24 ` Marr
2006-02-27 21:53 ` Hans Reiser
2006-02-28 0:03 ` Bill Davidsen
2006-02-28 18:38 ` Hans Reiser
2006-03-05 23:02 ` Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?) Linda Walsh
2006-03-07 19:53 ` Marr
2006-03-07 21:15 ` Linda Walsh
2006-03-12 21:53 ` Marr
2006-03-12 22:15 ` Mark Lord [this message]
2006-03-13 4:36 ` Marr
2006-03-13 14:41 ` Mark Lord
2006-03-13 18:15 ` Hans Reiser
2006-03-13 20:00 ` Marr
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=44149D6A.7080005@rtr.ca \
--to=lkml@rtr.ca \
--cc=akpm@osdl.org \
--cc=davidsen@tmr.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lkml@tlinx.org \
--cc=marr@flex.com \
--cc=reiserfs-dev@namesys.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.