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From: Peter Zijlstra <peterz@infradead.org>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	David Howells <dhowells@redhat.com>,
	torvalds@linux-foundation.org, Enrik.Berkhan@ge.com,
	uclinux-dev@uclinux.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] NOMMU: Pages allocated to a ramfs inode's pagecache may get wrongly discarded
Date: Fri, 13 Mar 2009 08:57:16 +0100	[thread overview]
Message-ID: <1236931036.5188.80.camel@laptop> (raw)
In-Reply-To: <20090313105618.43DF.A69D9226@jp.fujitsu.com>

On Fri, 2009-03-13 at 11:03 +0900, KOSAKI Motohiro wrote:
> Hi
> 
> > > Which as Peter points out:
> > > 
> > > 	The ramfs stuff is rather icky in that it adds the pages to the aging
> > > 	list, marks them dirty, but does not provide a writeout method. 
> > > 
> > > 	This will make the paging code scan over them (continuously) trying to
> > > 	clean them, failing that (lack of writeout method) and putting them back
> > > 	on the list.
> > > 
> > > Not requiring the pages to be added to the LRU would be a really good idea.
> > > They are not discardable, be it in MMU or NOMMU mode, except when the inode
> > > itself is discarded.
> > 
> > Yep, these pages shouldn't be on the LRU at all.  I guess that will
> > require some tweaks to core filemap.c code.
> 
> IMHO, UNEVICTABLE_LRU already does lru isolation.
> only rest prblem is, getting rid of "depends on MMU" line in mm/Kconfig.
> 
> Am I missing anything?

Yes, the need to take something off that shouldn't be there to begin
with.


  reply	other threads:[~2009-03-13  7:58 UTC|newest]

Thread overview: 101+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-11 15:30 [PATCH] NOMMU: Pages allocated to a ramfs inode's pagecache may get wrongly discarded David Howells
2009-03-11 17:26 ` Johannes Weiner
2009-03-11 22:03 ` Andrew Morton
2009-03-11 22:03   ` Andrew Morton
2009-03-11 22:36   ` Johannes Weiner
2009-03-11 22:36     ` Johannes Weiner
2009-03-12  0:02   ` Andrew Morton
2009-03-12  0:02     ` Andrew Morton
2009-03-12  0:35     ` Minchan Kim
2009-03-12  0:35       ` Minchan Kim
2009-03-12  1:04       ` KOSAKI Motohiro
2009-03-12  1:04         ` KOSAKI Motohiro
2009-03-12  1:52         ` Minchan Kim
2009-03-12  1:52           ` Minchan Kim
2009-03-12  1:56           ` Minchan Kim
2009-03-12  1:56             ` Minchan Kim
2009-03-12  2:00           ` KOSAKI Motohiro
2009-03-12  2:00             ` KOSAKI Motohiro
2009-03-12  2:11             ` Minchan Kim
2009-03-12  2:11               ` Minchan Kim
2009-03-12 12:19         ` Robin Getz
2009-03-12 12:19           ` Robin Getz
2009-03-12 17:55           ` [uClinux-dev] " Jamie Lokier
2009-03-12 17:55             ` Jamie Lokier
2009-03-13 11:53         ` David Howells
2009-03-13 11:53           ` David Howells
2009-03-13 22:49           ` Johannes Weiner
2009-03-13 22:49             ` Johannes Weiner
2009-03-13 17:33         ` [PATCH 0/2] Make the Unevictable LRU available on NOMMU David Howells
2009-03-13 17:33           ` David Howells
2009-03-13 17:33           ` [PATCH 1/2] NOMMU: There is no mlock() for NOMMU, so don't provide the bits David Howells
2009-03-13 17:33             ` David Howells
2009-03-14 11:17             ` KOSAKI Motohiro
2009-03-14 11:17               ` KOSAKI Motohiro
2009-03-13 17:33           ` [PATCH 2/2] NOMMU: Make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=n David Howells
2009-03-13 17:33             ` David Howells
2009-03-14 11:17             ` KOSAKI Motohiro
2009-03-14 11:17               ` KOSAKI Motohiro
2009-03-14  0:27           ` [PATCH 0/2] Make the Unevictable LRU available on NOMMU Minchan Kim
2009-03-14  0:27             ` Minchan Kim
2009-03-20 16:08             ` Lee Schermerhorn
2009-03-20 16:08               ` Lee Schermerhorn
2009-03-20 16:24               ` David Howells
2009-03-20 16:24                 ` David Howells
2009-03-20 18:30                 ` Lee Schermerhorn
2009-03-20 18:30                   ` Lee Schermerhorn
2009-03-21 10:20                   ` Johannes Weiner
2009-03-21 10:20                     ` Johannes Weiner
2009-03-22 20:13                     ` [patch 1/3] mm: decouple unevictable lru from mmu Johannes Weiner
2009-03-22 20:13                       ` Johannes Weiner
2009-03-22 23:46                       ` KOSAKI Motohiro
2009-03-22 23:46                         ` KOSAKI Motohiro
2009-03-23  0:14                         ` Johannes Weiner
2009-03-23  0:14                           ` Johannes Weiner
2009-03-23 10:48                           ` David Howells
2009-03-23 10:48                             ` David Howells
2009-03-22 20:13                     ` [patch 2/3] ramfs-nommu: use generic lru cache Johannes Weiner
2009-03-22 20:13                       ` Johannes Weiner
2009-03-23  2:22                       ` KOSAKI Motohiro
2009-03-23  2:22                         ` KOSAKI Motohiro
2009-03-23 10:40                       ` David Howells
2009-03-23 10:40                         ` David Howells
2009-03-22 20:13                     ` [patch 3/3] mm: keep pages from unevictable mappings off the LRU lists Johannes Weiner
2009-03-22 20:13                       ` Johannes Weiner
2009-03-23  0:44                       ` Minchan Kim
2009-03-23  0:44                         ` Minchan Kim
2009-03-23  2:21                         ` KOSAKI Motohiro
2009-03-23  2:21                           ` KOSAKI Motohiro
2009-03-23  8:42                           ` Johannes Weiner
2009-03-23  8:42                             ` Johannes Weiner
2009-03-23  9:01                             ` KOSAKI Motohiro
2009-03-23  9:01                               ` KOSAKI Motohiro
2009-03-23  9:23                               ` KOSAKI Motohiro
2009-03-23  9:23                                 ` KOSAKI Motohiro
2009-03-26  0:48                                 ` Johannes Weiner
2009-03-26  0:48                                   ` Johannes Weiner
2009-03-23 10:53                       ` David Howells
2009-03-23 10:53                         ` David Howells
2009-03-26  0:01                         ` Johannes Weiner
2009-03-26  0:01                           ` Johannes Weiner
2009-03-26  8:56                           ` KOSAKI Motohiro
2009-03-26  8:56                             ` KOSAKI Motohiro
2009-03-26 10:36                             ` Johannes Weiner
2009-03-26 10:36                               ` Johannes Weiner
2009-03-23 20:07                     ` [PATCH 0/2] Make the Unevictable LRU available on NOMMU Lee Schermerhorn
2009-03-23 20:07                       ` Lee Schermerhorn
2009-03-12  0:08 ` [PATCH] NOMMU: Pages allocated to a ramfs inode's pagecache may get wrongly discarded Andrew Morton
2009-03-12  7:12   ` Berkhan, Enrik (GE Infra, Oil & Gas)
2009-03-12 11:29     ` [uClinux-dev] " Jamie Lokier
2009-03-12 11:50       ` Peter Zijlstra
2009-03-12 23:20         ` Minchan Kim
2009-03-13  7:56           ` Peter Zijlstra
2009-03-13  9:17             ` Minchan Kim
2009-03-12 12:25   ` David Howells
2009-03-12 19:43     ` Andrew Morton
2009-03-13  2:03       ` KOSAKI Motohiro
2009-03-13  7:57         ` Peter Zijlstra [this message]
2009-03-13  8:15           ` KOSAKI Motohiro
2009-03-13  9:19             ` Minchan Kim
2009-03-13 10:44             ` Johannes Weiner
2009-03-14 14:29               ` KOSAKI Motohiro

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