From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: dhylands@gmail.com, guinan@bluebutton.com, linux-kernel@vger.kernel.org
Subject: Re: get_user_pages() cache issues on ARM
Date: Sat, 30 Sep 2006 18:05:48 +0100 [thread overview]
Message-ID: <20060930170548.GA24949@flint.arm.linux.org.uk> (raw)
In-Reply-To: <E1GTiBq-0002i3-00@dorka.pomaz.szeredi.hu>
On Sat, Sep 30, 2006 at 06:59:50PM +0200, Miklos Szeredi wrote:
> Hi Russell,
>
> The get_user_pages() vs dcache coherency issue still seems to be
> unresolved on ARM.
>
> See flush_anon_page() and flush_kernel_dcache_page() in
> Documentation/cachetlb.txt and their implementation on PARISC.
>
> Can you please take a look at this?
I'm sorry, I don't think I have sufficient understanding of the Linux VM
to look at these issues anymore.
The questions I have are:
- where do these pages that get_user_pages() finds and calls flush_anon_page()
on come from?
- why is the current ARM flush_dcache_page() (which is also called after
flush_anon_page()) not sufficient?
- if we implement flush_anon_page() does that mean that we end up flushing
multiple times in some circumstances? If so, how do we avoid this?
I'm really serious - I no longer understand the Linux VM sufficiently to
get this stuff right.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
next prev parent reply other threads:[~2006-09-30 17:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-30 16:59 get_user_pages() cache issues on ARM Miklos Szeredi
2006-09-30 17:05 ` Russell King [this message]
2006-09-30 17:18 ` Miklos Szeredi
2006-10-07 13:13 ` James Bottomley
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=20060930170548.GA24949@flint.arm.linux.org.uk \
--to=rmk+lkml@arm.linux.org.uk \
--cc=dhylands@gmail.com \
--cc=guinan@bluebutton.com \
--cc=linux-kernel@vger.kernel.org \
--cc=miklos@szeredi.hu \
/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.