From: Andrew Morton <akpm@digeo.com>
To: Daniel Phillips <phillips@arcor.de>
Cc: imran.badr@cavium.com, root@chaos.analogic.com,
"'David S. Miller'" <davem@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: Calculating kernel logical address ..
Date: Mon, 09 Sep 2002 12:14:42 -0700 [thread overview]
Message-ID: <3D7CF322.98045305@digeo.com> (raw)
In-Reply-To: 20020909190328Z16576-16323+113@humbolt.nl.linux.org
Daniel Phillips wrote:
>
> ...
> > down(¤t->mm->mmap_sem) would help.
>
> Not for anon pages, and how do you know whether it's anon or not before
> looking at the page, which may be free by the time you look at it?
> In other words, mm->page_table_lock is the one, because it's required
> for unmapping a pte, and any mapped page will be forced to hold a count
> increment until it gets past that lock. Without this lock, the results
> of pte_page are unstable.
The caller of get_user_pages() needs to hold mmap_sem for reading
to prevent the vmas from going away. get_user_pages() does the
right thing wrt page_table_lock. (As a quick peek at the code
would reveal...)
next prev parent reply other threads:[~2002-09-09 19:10 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-09 17:06 Calculating kernel logical address Imran Badr
2002-09-09 17:29 ` Richard B. Johnson
2002-09-09 17:23 ` David S. Miller
2002-09-09 17:34 ` Martin J. Bligh
2002-09-09 17:40 ` Daniel Phillips
2002-09-09 17:31 ` Imran Badr
2002-09-09 18:00 ` Richard B. Johnson
2002-09-09 18:12 ` Imran Badr
2002-09-09 18:27 ` Daniel Phillips
2002-09-09 18:41 ` Imran Badr
2002-09-09 21:55 ` Alan Cox
2002-09-09 22:52 ` Imran Badr
2002-09-09 23:09 ` Alan Cox
2002-09-09 18:13 ` Jesse Barnes
2002-09-09 18:25 ` Daniel Phillips
2002-09-09 19:40 ` Andrew Morton
2002-09-09 20:41 ` Daniel Phillips
2002-09-10 6:43 ` Jens Axboe
2002-09-10 7:12 ` Andrew Morton
2002-09-09 18:42 ` Andrew Morton
2002-09-10 7:03 ` Gerd Knorr
2002-09-09 18:16 ` Kurt Ferreira
2002-09-09 18:17 ` David S. Miller
2002-09-09 18:17 ` Daniel Phillips
2002-09-09 18:43 ` Richard B. Johnson
2002-09-09 18:50 ` Daniel Phillips
2002-09-09 18:57 ` Richard B. Johnson
2002-09-09 18:08 ` Andrew Morton
2002-09-09 18:23 ` Daniel Phillips
2002-09-09 18:49 ` Imran Badr
2002-09-09 18:46 ` David S. Miller
2002-09-09 19:06 ` Daniel Phillips
2002-09-09 19:14 ` Andrew Morton [this message]
2002-09-09 19:23 ` Imran Badr
-- strict thread matches above, loose matches on Subject: below --
2002-09-09 21:19 Manfred Spraul
2002-09-09 21:47 ` Andrew Morton
2002-09-10 17:01 ` Manfred Spraul
2002-09-09 21:02 Manfred Spraul
2002-09-09 21:07 ` Imran Badr
2002-09-06 15:44 Manfred Spraul
2002-09-06 17:13 ` Imran Badr
2002-09-07 1:57 ` Daniel Phillips
2002-09-06 3:23 side-by-side Re: BYTE Unix Benchmarks Version 3.6 Daniel Phillips
2002-09-06 3:34 ` Calculating kernel logical address Imran Badr
2002-09-07 1:44 ` Daniel Phillips
2002-09-08 0:01 ` David S. Miller
2002-09-08 18:44 ` Daniel Phillips
2002-09-09 5:00 ` David S. Miller
2002-09-09 5:17 ` Daniel Phillips
2002-09-09 5:28 ` David S. Miller
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=3D7CF322.98045305@digeo.com \
--to=akpm@digeo.com \
--cc=davem@redhat.com \
--cc=imran.badr@cavium.com \
--cc=linux-kernel@vger.kernel.org \
--cc=phillips@arcor.de \
--cc=root@chaos.analogic.com \
/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.