From: David Woodhouse <dwmw2@infradead.org>
To: "Bradley D. LaRonde" <brad@ltc.com>
Cc: "Thomas Capricelli" <orzel@kde.org>, linux-kernel@vger.kernel.org
Subject: Re: Mounting a in-ROM filesystem efficiently
Date: Fri, 14 Dec 2001 09:45:56 +0000 [thread overview]
Message-ID: <25867.1008323156@redhat.com> (raw)
In-Reply-To: <066801c183f2$53f90ec0$5601010a@prefect>
In-Reply-To: <066801c183f2$53f90ec0$5601010a@prefect> <20011213160007.D998D23CCB@persephone.dmz.logatique.fr>
brad@ltc.com said:
> have maintained, on and off, a patch to crafms that supports
> traditional cramfs decompress-and-read/run-from-RAM, plus direct
> mmaping with no decompression and read/run straight out of ROM:
> http://www.ltc.com/~brad/mips/cramfs-linear-root-xip-linux-2.4.9-2.diff
+ if (remap_page_range(vma->vm_start, KSEG0ADDR(address), length,
+ vma->vm_page_prot))
Cute, but not very generic. The approach I was contemplating was to
allocate a set of 'struct page's for the pages containing XIP data, then
add those pages to the page cache manually on read_inode().
It's a shame that ->readpage() doesn't get to say 'actually I used my own
page for that, I didn't want one allocated for me'.
Extending the MTD API to return a set of pages representing a particular
device, and handling the locking so that we don't try to write to the chips
while pages are mapped, will also be necessary if we want to do it with
flash chips that are used for anything else.
--
dwmw2
next prev parent reply other threads:[~2001-12-14 9:46 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-12-13 16:02 Mounting a in-ROM filesystem efficiently Thomas Capricelli
2001-12-13 16:22 ` Bradley D. LaRonde
2001-12-13 16:41 ` Thomas Capricelli
2001-12-13 17:10 ` Bradley D. LaRonde
2001-12-13 18:02 ` Richard B. Johnson
2001-12-13 18:14 ` Bradley D. LaRonde
2001-12-13 18:34 ` Richard B. Johnson
2001-12-13 18:52 ` Bradley D. LaRonde
2001-12-13 19:41 ` Richard B. Johnson
2001-12-13 20:09 ` Bradley D. LaRonde
[not found] ` <08d701c18412/mnt/tmp/sendmee91d2c0601010a@prefect>
2001-12-18 1:27 ` Pavel Machek
2001-12-14 11:03 ` Catalin Marinas
2001-12-13 17:49 ` David Woodhouse
2001-12-13 18:06 ` Bradley D. LaRonde
2001-12-13 20:38 ` H. Peter Anvin
2001-12-13 20:52 ` Bradley D. LaRonde
2001-12-14 9:45 ` David Woodhouse [this message]
2001-12-14 15:27 ` Bradley D. LaRonde
2001-12-14 16:51 ` David Woodhouse
2001-12-14 17:02 ` Bradley D. LaRonde
2001-12-14 17:03 ` David Woodhouse
2001-12-14 17:12 ` Bradley D. LaRonde
2001-12-14 17:16 ` David Woodhouse
2001-12-14 17:27 ` Bradley D. LaRonde
2001-12-16 9:51 ` Christoph Rohland
2002-01-23 8:01 ` Eric W. Biederman
[not found] <20011214072540.D7457@duron.intern.kubla.de>
2001-12-17 13:24 ` Richard B. Johnson
2001-12-18 12:10 ` Helge Hafting
2001-12-18 14:00 ` Richard B. Johnson
2001-12-18 14:09 ` Alan Cox
2001-12-18 15:21 ` Mr. James W. Laferriere
2001-12-18 20:56 ` H. Peter Anvin
2001-12-18 16:27 ` Kent Borg
2001-12-18 17:05 ` Herman Oosthuysen
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