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From: Tim Chen <tim.c.chen@linux.intel.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: Change in default vm_dirty_ratio
Date: Mon, 18 Jun 2007 14:14:30 -0700	[thread overview]
Message-ID: <1182201271.4883.22.camel@localhost.localdomain> (raw)

Andrew,

The default vm_dirty_ratio changed from 40 to 10
for the 2.6.22-rc kernels in this patch:
 
http://git.kernel.org/?
p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=07db59bd6b0f279c31044cba6787344f63be87ea;hp=de46c33745f5e2ad594c72f2cf5f490861b16ce1

IOZone write drops by about 60% when test file size is 50 percent of
memory.  Rand-write drops by 90%. 

Is there a good reason for turning down the default dirty ratio?
How will it help for most cases?  Intuitively, it seems like 
a less aggressive writeback will have better performance.

Thanks.

Tim

             reply	other threads:[~2007-06-18 23:08 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-18 21:14 Tim Chen [this message]
2007-06-18 23:47 ` Change in default vm_dirty_ratio Andrew Morton
2007-06-19  0:06   ` Linus Torvalds
2007-06-19  0:09     ` Arjan van de Ven
2007-06-19 18:41   ` John Stoffel
2007-06-19 19:04     ` Linus Torvalds
2007-06-19 19:06       ` Linus Torvalds
2007-06-19 22:33       ` David Miller
2007-06-19 19:57   ` Andi Kleen
2007-06-20  4:24   ` Dave Jones
2007-06-20  4:44     ` Andrew Morton
2007-06-20  8:35       ` Peter Zijlstra
2007-06-20  8:58         ` Andrew Morton
2007-06-20  9:14           ` Jens Axboe
2007-06-20  9:19             ` Peter Zijlstra
2007-06-20  9:20               ` Jens Axboe
2007-06-20  9:43                 ` Peter Zijlstra
2007-06-21 22:53                 ` Matt Mackall
2007-06-21 23:08                   ` Linus Torvalds
2007-06-23 18:23                     ` Peter Zijlstra
2007-06-24 16:40                       ` Linus Torvalds
2007-06-25  0:15                         ` Peter Zijlstra
2007-06-20  9:19           ` Peter Zijlstra
2007-06-21 16:54           ` Mark Lord
2007-06-21 16:55             ` Peter Zijlstra
2007-06-20 17:17         ` Linus Torvalds
2007-06-20 18:12           ` Arjan van de Ven
2007-06-20 18:28             ` Linus Torvalds
2007-06-21 12:37     ` Nadia Derbey

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