From: Ralf Baechle <ralf@linux-mips.org>
To: Peter Horton <pdh@colonel-panic.org>
Cc: Jun Sun <jsun@mvista.com>, Bob Breuer <bbreuer@righthandtech.com>,
linux-mips@linux-mips.org
Subject: Re: problems on D-cache alias in 2.4.22
Date: Tue, 18 May 2004 21:50:55 +0200 [thread overview]
Message-ID: <20040518195055.GB2454@linux-mips.org> (raw)
In-Reply-To: <20040518191019.GA11007@skeleton-jack>
On Tue, May 18, 2004 at 08:10:19PM +0100, Peter Horton wrote:
> The kernel maps the page cache page into user space ... BANG! possible
> D-cache alias.
>
> The kernel doesn't bother flushing the page cache page from the D-cache
> as it's never accessed at it's page cache address.
It is - after all the driver is copying the data to there. The same
problem also exists in the ramdisk driver and there it has been fixed
properly, it seems.
> The current fix in the Cobalt patches (2.4 & 2.6) just flushes the read
> data out of the D-cache after every IDE insw()/insl(). This is the least
> intrusive fix.
>
> Some Sparc machines also see this problem.
Carelessly written PIO drivers on any architecture would suffer from this
kind of problem.
Ralf
next prev parent reply other threads:[~2004-05-18 19:51 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-18 18:17 problems on D-cache alias in 2.4.22 Bob Breuer
2004-05-18 18:17 ` Bob Breuer
2004-05-18 18:45 ` Jun Sun
2004-05-18 19:10 ` Peter Horton
2004-05-18 19:50 ` Ralf Baechle [this message]
2004-05-18 18:24 ` Alan Cox
2004-05-18 21:21 ` Peter Horton
2004-05-18 22:25 ` Jun Sun
2004-05-18 23:29 ` Peter Horton
2004-05-18 20:02 ` Ralf Baechle
2004-05-18 20:10 ` Thiemo Seufer
-- strict thread matches above, loose matches on Subject: below --
2004-05-13 22:05 Bob Breuer
2004-05-13 22:05 ` Bob Breuer
2004-05-14 2:59 ` wuming
2004-05-14 7:52 ` Peter Horton
2004-05-15 0:12 ` Ralf Baechle
2004-05-15 12:31 ` Fuxin Zhang
2004-05-13 6:52 wuming
2004-05-14 7:45 ` Peter Horton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20040518195055.GB2454@linux-mips.org \
--to=ralf@linux-mips.org \
--cc=bbreuer@righthandtech.com \
--cc=jsun@mvista.com \
--cc=linux-mips@linux-mips.org \
--cc=pdh@colonel-panic.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.