public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Wu Fengguang <wfg@mail.ustc.edu.cn>
To: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>,
	linux-kernel@vger.kernel.org, Andrew Morton <akpm@osdl.org>,
	Jens Axboe <axboe@suse.de>, Nick Piggin <nickpiggin@yahoo.com.au>,
	Badari Pulavarty <pbadari@us.ibm.com>
Subject: Re: [RFC] kernel facilities for cache prefetching
Date: Sat, 6 May 2006 09:11:25 +0800	[thread overview]
Message-ID: <346877876.18033@ustc.edu.cn> (raw)
Message-ID: <20060506011125.GA9099@mail.ustc.edu.cn> (raw)
In-Reply-To: <Pine.LNX.4.64.0605031816480.13777@cuia.boston.redhat.com>

On Wed, May 03, 2006 at 06:20:29PM -0400, Rik van Riel wrote:
> Why not simply read everything in a whole file at a time
> at boot time, while we still have enough free memory ?

Sure it helps, though may be unnecessary once we can rely on userspace
pre-caching tools to do it in a more accurate and efficient way.

The main concern would be inter-file/inter-buffer readahead.
I have some data to support it:

% wc -l hda* startup.files
 1743 hda2_buffers      <== my /
 335 hda3_buffers       <== my /home
 1130 startup.files
 3208 total

The above cache sizes sum up to ~110MB, so it's about 36KB per seek.

Thanks,
Wu

  reply	other threads:[~2006-05-06  1:11 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20060502075049.GA5000@mail.ustc.edu.cn>
2006-05-02  7:50 ` [RFC] kernel facilities for cache prefetching Wu Fengguang
2006-05-02 12:46   ` Diego Calleja
     [not found]     ` <20060502144203.GA10594@mail.ustc.edu.cn>
2006-05-02 14:42       ` Wu Fengguang
2006-05-02 16:07         ` Diego Calleja
     [not found]           ` <20060503064503.GA4781@mail.ustc.edu.cn>
2006-05-03  6:45             ` Wu Fengguang
2006-05-03 18:14               ` Diego Calleja
2006-05-03 23:39                 ` Zan Lynx
2006-05-04  1:37                   ` Diego Calleja
2006-05-02 15:55   ` Linus Torvalds
2006-05-02 16:35     ` Andi Kleen
     [not found]     ` <20060503071325.GC4781@mail.ustc.edu.cn>
2006-05-03  7:13       ` Wu Fengguang
2006-05-03 12:59     ` Nikita Danilov
     [not found]     ` <20060503041106.GC5915@mail.ustc.edu.cn>
2006-05-03  4:11       ` Wu Fengguang
2006-05-03 17:28       ` Badari Pulavarty
     [not found]         ` <346733486.30800@ustc.edu.cn>
2006-05-04 15:03           ` Linus Torvalds
2006-05-04 16:57             ` Badari Pulavarty
     [not found]             ` <20060505144451.GA6134@mail.ustc.edu.cn>
2006-05-05 14:44               ` Wu Fengguang
2006-05-03 22:20     ` Rik van Riel
     [not found]       ` <20060506011125.GA9099@mail.ustc.edu.cn>
2006-05-06  1:11         ` Wu Fengguang [this message]
2006-05-04  0:28     ` Linda Walsh
2006-05-04  1:31       ` Linus Torvalds
2006-05-04  7:08         ` Ph. Marek
2006-05-04  7:33           ` Arjan van de Ven
     [not found]             ` <20060504121454.GB6008@mail.ustc.edu.cn>
2006-05-04 12:14               ` Wu Fengguang
2006-05-04 12:34               ` Arjan van de Ven
2006-05-03 21:45   ` Linda Walsh
     [not found]     ` <20060504121212.GA6008@mail.ustc.edu.cn>
2006-05-04 12:12       ` Wu Fengguang
2006-05-04 18:57         ` Linda Walsh
     [not found]           ` <20060505152007.GB6134@mail.ustc.edu.cn>
2006-05-05 15:20             ` Wu Fengguang
2006-05-04  9:02   ` Helge Hafting
2006-05-02  7:58 ` Arjan van de Ven
     [not found]   ` <20060502080619.GA5406@mail.ustc.edu.cn>
2006-05-02  8:06     ` Wu Fengguang
2006-05-02  8:30     ` Arjan van de Ven
     [not found]       ` <20060502085325.GA9190@mail.ustc.edu.cn>
2006-05-02  8:53         ` Wu Fengguang
2006-05-06  6:49           ` Denis Vlasenko
2006-05-02  8:55         ` Arjan van de Ven
2006-05-02 11:39           ` Jan Engelhardt
     [not found]           ` <20060502114853.GA9983@mail.ustc.edu.cn>
2006-05-02 11:48             ` Wu Fengguang
2006-05-02 22:03       ` Dave Jones
2006-05-02  8:09 ` Jens Axboe
     [not found]   ` <20060502082009.GA9038@mail.ustc.edu.cn>
2006-05-02  8:20     ` Wu Fengguang
2006-05-03 22:05   ` Benjamin LaHaise
2006-05-02 19:10 ` Pavel Machek
2006-05-02 23:36   ` Nigel Cunningham
     [not found]     ` <20060503023505.GB5915@mail.ustc.edu.cn>
2006-05-03  2:35       ` Wu Fengguang
     [not found]   ` <20060503023223.GA5915@mail.ustc.edu.cn>
2006-05-03  2:32     ` Wu Fengguang
     [not found]   ` <20060503071948.GD4781@mail.ustc.edu.cn>
2006-05-03  7:19     ` Wu Fengguang
     [not found]   ` <20060504122830.GA6205@mail.ustc.edu.cn>
2006-05-04 12:28     ` Wu Fengguang

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=346877876.18033@ustc.edu.cn \
    --to=wfg@mail.ustc.edu.cn \
    --cc=akpm@osdl.org \
    --cc=axboe@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nickpiggin@yahoo.com.au \
    --cc=pbadari@us.ibm.com \
    --cc=riel@redhat.com \
    --cc=torvalds@osdl.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