From: David Miller <davem@davemloft.net>
To: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org, peterz@infradead.org,
jack@suse.cz, linux-kernel@vger.kernel.org, linux-mm@kvack.org,
npiggin@suse.de
Subject: Re: Increase dirty_ratio and dirty_background_ratio?
Date: Thu, 08 Jan 2009 08:24:13 -0800 (PST) [thread overview]
Message-ID: <20090108.082413.156881254.davem@davemloft.net> (raw)
In-Reply-To: <20090108030245.e7c8ceaf.akpm@linux-foundation.org>
From: Andrew Morton <akpm@linux-foundation.org>
Date: Thu, 8 Jan 2009 03:02:45 -0800
> The kernel can't get this right - it doesn't know the usage
> patterns/workloads, etc.
I don't agree with that.
The kernel is watching and gets to see every operation that happens
both to memory and to the disk, so of course it can see what
the "patterns" and the "workload" are.
It also can see how fast or slow the disk technology is. And I think
that is one of the largest determinants to what these values should
be set to.
So, in fact, the kernel is the place that has all of the information
necessary to try and adjust these settings dynamically.
Userland can only approximate a good setting, at best, because it has
so many fewer pieces of information to work with.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2009-01-08 16:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20090107154517.GA5565@duck.suse.cz>
2009-01-07 16:25 ` Peter Zijlstra
2009-01-07 16:39 ` Linus Torvalds
2009-01-07 20:51 ` David Miller
2009-01-08 11:02 ` Andrew Morton
2009-01-08 16:24 ` David Miller [this message]
2009-01-08 16:48 ` Linus Torvalds
2009-01-08 16:55 ` Chris Mason
2009-01-08 17:05 ` Linus Torvalds
2009-01-08 19:57 ` Jan Kara
2009-01-08 20:01 ` David Miller
2009-01-09 18:02 ` Jan Kara
2009-01-09 19:00 ` Andrew Morton
2009-01-09 19:07 ` Chris Mason
2009-01-09 22:31 ` david
2009-01-09 21:34 ` Peter Zijlstra
2009-01-14 3:29 ` Nick Piggin
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=20090108.082413.156881254.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=akpm@linux-foundation.org \
--cc=jack@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=npiggin@suse.de \
--cc=peterz@infradead.org \
--cc=torvalds@linux-foundation.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