From: Randy Dunlap <randy.dunlap@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>, "J.H." <warthog9@kernel.org>,
kernel list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sysctl: vfs_cache_divisor
Date: Mon, 19 Mar 2007 13:42:36 -0700 [thread overview]
Message-ID: <45FEF5BC.90809@oracle.com> (raw)
In-Reply-To: <20070319133613.9f4881db.akpm@linux-foundation.org>
Andrew Morton wrote:
> On Mon, 19 Mar 2007 12:27:40 -0700
> Randy Dunlap <randy.dunlap@oracle.com> wrote:
>
>> +The default vfs_cache_divisor value is 100 (like percent). However, for
>> +extremely large systems where a value of vfs_cache_pressure of less than
>> +1 percent is desirable, using a larger vfs_cache_divisor enables this wanted
>> +characteristic.
>
> The one-percent-granularity problem also applies to /proc/sys/vm/*dirty*
> and possibly other things. So any fix we do should be applicable to those
> as well.
>
> And I'm not really sure how we should do this. I do think that we should
> change the kernel so these knobs are internally higher-resolution. So, for
> example, we switch all the logic so that instead of these variables
> representing 1/100th, they instead represent 1/1000000th, for example.
>
> Then, we change the top-level /proc handler to do the 1/100th <-> 1/1000000th
> conversion. So the rest of the kernel doesn't have to know about it.
>
> The we duplicate all the relevant /proc knobs:
>
> cat /proc/sys/vm/dirty_ratio
> 30
> cat /proc/sys/vm/hires-dirty_ratio/
> 300000
>
> Or we do something else ;)
Sounds better. I wasn't very keen on the userspace interface that this
exposed. Will look at those.
--
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
next prev parent reply other threads:[~2007-03-19 20:45 UTC|newest]
Thread overview: 110+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-14 22:37 kernel.org lies about latest -mm kernel Pavel Machek
2006-12-14 23:01 ` Randy Dunlap
2006-12-14 23:38 ` Sergio Monteiro Basto
2006-12-16 17:44 ` [KORG] " Randy Dunlap
2006-12-16 17:57 ` Andrew Morton
2006-12-16 18:02 ` Randy Dunlap
2006-12-16 19:30 ` J.H.
2006-12-16 20:30 ` Russell King
2006-12-26 16:47 ` H. Peter Anvin
2006-12-16 21:21 ` Nigel Cunningham
2006-12-26 16:49 ` H. Peter Anvin
2007-01-07 3:35 ` Nigel Cunningham
2007-01-07 4:10 ` Jeff Garzik
2007-01-07 4:47 ` Nigel Cunningham
2007-01-07 4:22 ` Jeff Garzik
2007-01-07 4:29 ` Linus Torvalds
2007-01-07 20:11 ` Greg KH
2007-01-07 21:30 ` H. Peter Anvin
2007-01-07 5:17 ` H. Peter Anvin
2007-01-07 5:24 ` How git affects kernel.org performance H. Peter Anvin
2007-01-07 5:39 ` Linus Torvalds
2007-01-07 8:55 ` Willy Tarreau
2007-01-07 8:58 ` H. Peter Anvin
2007-01-07 9:03 ` Willy Tarreau
2007-01-07 10:28 ` Christoph Hellwig
2007-01-07 10:52 ` Willy Tarreau
2007-01-07 18:17 ` Linus Torvalds
2007-01-07 19:13 ` Linus Torvalds
[not found] ` <9e4733910701071126r7931042eldfb73060792f4f41@mail.gmail.com>
2007-01-07 19:35 ` Linus Torvalds
2007-01-07 10:50 ` Jan Engelhardt
2007-01-07 18:49 ` Randy Dunlap
2007-01-07 19:07 ` Jan Engelhardt
2007-01-07 19:28 ` Randy Dunlap
2007-01-07 19:37 ` Linus Torvalds
2007-01-07 9:15 ` Andrew Morton
2007-01-07 9:38 ` Rene Herman
2007-01-08 3:05 ` Suparna Bhattacharya
2007-01-08 12:58 ` Theodore Tso
2007-01-08 13:41 ` Johannes Stezenbach
2007-01-08 13:56 ` Theodore Tso
2007-01-08 13:59 ` Pavel Machek
2007-01-08 14:17 ` Theodore Tso
2007-01-08 13:43 ` Jeff Garzik
2007-01-09 1:09 ` Paul Jackson
2007-01-09 2:18 ` Jeremy Higdon
[not found] ` <20070109075945.GA8799@mail.ustc.edu.cn>
2007-01-09 7:59 ` Fengguang Wu
2007-01-09 16:23 ` Linus Torvalds
[not found] ` <20070110015739.GA26978@mail.ustc.edu.cn>
2007-01-10 1:57 ` Fengguang Wu
2007-01-10 3:20 ` Nigel Cunningham
[not found] ` <20070110140730.GA986@mail.ustc.edu.cn>
2007-01-10 14:07 ` Fengguang Wu
2007-01-12 10:54 ` Nigel Cunningham
2007-01-07 14:57 ` Robert Fitzsimons
2007-01-07 19:12 ` J.H.
2007-01-08 1:51 ` Jakub Narebski
2007-01-07 15:06 ` Krzysztof Halasa
2007-01-07 20:31 ` Shawn O. Pearce
2007-01-08 14:46 ` Nicolas Pitre
2007-01-09 4:29 ` [KORG] Re: kernel.org lies about latest -mm kernel Nigel Cunningham
2007-01-09 5:09 ` Adrian Bunk
2007-01-09 5:51 ` Nigel Cunningham
2006-12-17 12:32 ` Pavel Machek
2006-12-17 13:13 ` Jeff Garzik
2006-12-17 18:23 ` Randy Dunlap
2006-12-17 22:37 ` Matti Aarnio
2006-12-18 0:42 ` J.H.
2006-12-19 6:46 ` Willy Tarreau
2006-12-19 7:39 ` J.H.
2006-12-19 13:32 ` Willy Tarreau
2006-12-19 14:36 ` Dave Jones
2006-12-19 14:38 ` Willy Tarreau
2006-12-26 16:14 ` H. Peter Anvin
2007-01-08 20:10 ` Jean Delvare
2006-12-19 6:34 ` Willy Tarreau
2006-12-19 6:52 ` J.H.
2007-01-06 18:33 ` Randy Dunlap
2007-01-06 19:18 ` H. Peter Anvin
2007-01-06 19:35 ` Willy Tarreau
2007-01-06 19:37 ` Nicholas Miell
2007-01-06 20:13 ` Andrew Morton
2007-01-06 20:18 ` H. Peter Anvin
2007-03-19 19:27 ` [PATCH] sysctl: vfs_cache_divisor Randy Dunlap
2007-03-19 20:36 ` Andrew Morton
2007-03-19 20:42 ` Randy Dunlap [this message]
2007-03-20 4:22 ` H. Peter Anvin
2007-03-21 23:01 ` Randy Dunlap
2007-03-21 23:11 ` Andrew Morton
2007-03-23 0:07 ` Kyle Moffett
2007-03-23 20:36 ` Randy Dunlap
2007-03-23 20:59 ` H. Peter Anvin
2007-03-24 0:45 ` Kyle Moffett
2007-03-24 1:17 ` Kyle Moffett
2007-03-20 19:53 ` Ingo Oeser
2007-01-06 23:50 ` [KORG] Re: kernel.org lies about latest -mm kernel H. Peter Anvin
2007-01-06 20:13 ` Jeff Garzik
2007-01-06 20:17 ` Andrew Morton
2007-01-06 20:20 ` H. Peter Anvin
2007-01-06 20:36 ` Andrew Morton
2007-01-06 19:21 ` J.H.
2007-01-07 19:52 ` Randy Dunlap
2007-01-07 23:56 ` H. Peter Anvin
2006-12-26 17:02 ` H. Peter Anvin
2007-01-08 19:31 ` Jean Delvare
2007-01-08 19:37 ` Willy Tarreau
2007-01-08 22:05 ` Jean Delvare
2006-12-19 15:37 ` Tim Schmielau
2007-01-08 21:20 ` Jean Delvare
2007-01-08 21:33 ` J.H.
2007-01-09 7:01 ` Jean Delvare
2007-01-09 7:25 ` J.H.
2007-01-09 13:36 ` Jean Delvare
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