From: Jamie Lokier <jamie@shareable.org>
To: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>,
David Newall <davidn@davidnewall.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
hch@lst.de
Subject: Re: [RFC 0/7] [RFC] cramfs: fake write support
Date: Sun, 1 Jun 2008 13:28:18 +0100 [thread overview]
Message-ID: <20080601122818.GA3687@shareable.org> (raw)
In-Reply-To: <48421D65.8040301@lougher.demon.co.uk>
Phillip Lougher wrote:
> If I read the patches correctly, when a file page is written to, only
> that page gets copied into the page cache and locked, the other pages
> continue to be read off disk from cramfs? With Unionfs a page write
> causes the entire file to be copied up to the r/w tmpfs and locked into
> the page cache causing unnecessary RAM overhead.
Ok, so why not fix that in unionfs? An option so that holes in the
overlay file let through data from the underlying file sounds like it
would be generally useful, and quite easy to implement.
If not unionfs, a "union-tmpfs" combination would be good. Many
filesystems aren't well suited to being the overlay filesystem -
adding to the implementation's complexity - but a modified tmpfs could
be very well suited.
-- Jamie
next prev parent reply other threads:[~2008-06-01 12:28 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-31 15:37 [RFC 0/7] [RFC] cramfs: fake write support arnd
2008-05-31 18:56 ` David Newall
2008-05-31 20:40 ` Arnd Bergmann
2008-06-01 3:54 ` Phillip Lougher
2008-06-01 8:52 ` Arnd Bergmann
2008-06-01 12:28 ` Jamie Lokier [this message]
2008-06-01 21:49 ` Arnd Bergmann
2008-06-02 2:48 ` hooanon05
2008-06-02 3:25 ` Erez Zadok
2008-06-02 7:51 ` Arnd Bergmann
2008-06-02 18:13 ` Erez Zadok
2008-06-03 2:02 ` Phillip Lougher
2008-06-02 3:51 ` Erez Zadok
2008-06-02 11:07 ` Jamie Lokier
2008-06-02 4:37 ` Erez Zadok
2008-06-02 6:07 ` Bharata B Rao
2008-06-02 7:17 ` Jan Engelhardt
2008-06-02 7:12 ` Arnd Bergmann
2008-06-02 10:36 ` hooanon05
2008-06-02 11:15 ` Arnd Bergmann
2008-06-02 12:56 ` hooanon05
2008-06-02 14:13 ` Arnd Bergmann
2008-06-02 14:33 ` hooanon05
2008-06-02 15:01 ` Arnd Bergmann
2008-06-03 11:04 ` hooanon05
2008-06-02 14:54 ` Evgeniy Polyakov
2008-06-02 17:42 ` Arnd Bergmann
2008-06-02 15:35 ` Erez Zadok
2008-06-01 6:02 ` David Newall
2008-06-01 9:11 ` Jan Engelhardt
2008-06-01 16:25 ` Jörn Engel
2008-06-01 3:19 ` Phillip Lougher
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