From: "Jörn Engel" <joern@logfs.org>
To: Minchan Kim <minchan.kim@gmail.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>,
"Robert P. J. Day" <rpjday@crashcourse.ca>,
linux-mm@kvack.org
Subject: Re: why are some low-level MM routines being exported?
Date: Sun, 4 Apr 2010 21:55:33 +0200 [thread overview]
Message-ID: <20100404195533.GA8836@logfs.org> (raw)
In-Reply-To: <1270398112.1814.114.camel@barrios-desktop>
On Mon, 5 April 2010 01:21:52 +0900, Minchan Kim wrote:
> >
> Until now, other file system don't need it.
> Why do you need?
To avoid deadlocks. You tell logfs to write out some locked page, logfs
determines that it needs to run garbage collection first. Garbage
collection can read any page. If it called find_or_create_page() for
the locked page, you have a deadlock.
I don't know how (or if) jffs2 and ubifs can avoid this particular
scenario. The other filesystems lack garbage collection, so the problem
does not exist.
JA?rn
--
Joern's library part 5:
http://www.faqs.org/faqs/compression-faq/part2/section-9.html
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next prev parent reply other threads:[~2010-04-04 19:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-04 15:27 why are some low-level MM routines being exported? Robert P. J. Day
2010-04-04 15:59 ` Minchan Kim
2010-04-04 16:03 ` Evgeniy Polyakov
2010-04-04 16:17 ` Minchan Kim
2010-04-04 16:21 ` Minchan Kim
2010-04-04 18:15 ` Evgeniy Polyakov
2010-04-05 0:36 ` Minchan Kim
2010-04-05 12:47 ` Evgeniy Polyakov
2010-04-05 14:31 ` Minchan Kim
2010-04-04 19:55 ` Jörn Engel [this message]
2010-04-05 0:59 ` Minchan Kim
2010-04-05 5:30 ` Jörn Engel
2010-04-05 6:20 ` Minchan Kim
2010-04-05 6:22 ` Minchan Kim
2010-04-05 7:13 ` Jörn Engel
2010-04-05 8:26 ` Minchan Kim
2010-04-05 11:19 ` Jörn Engel
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