From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Christoph Lameter <clameter@sgi.com>
Cc: Andrea Arcangeli <andrea@qumranet.com>,
Avi Kivity <avi@qumranet.com>, Izik Eidus <izike@qumranet.com>,
Andrew Morton <akpm@osdl.org>, Nick Piggin <npiggin@suse.de>,
kvm-devel@lists.sourceforge.net, steiner@sgi.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
daniel.blueman@quadrics.com, holt@sgi.com,
Hugh Dickins <hugh@veritas.com>
Subject: Re: [kvm-devel] [PATCH] export notifier #1
Date: Wed, 23 Jan 2008 10:36:29 +1100 [thread overview]
Message-ID: <1201044989.6807.46.camel@pasglop> (raw)
In-Reply-To: <Pine.LNX.4.64.0801221232040.28197@schroedinger.engr.sgi.com>
On Tue, 2008-01-22 at 12:34 -0800, Christoph Lameter wrote:
>
> - Notifiers are called *after* we tore down ptes. At that point pages
> may already have been freed and reused. This means that there can
> still be uses of the page by the user of mmu_ops after the OS has
> dropped its mapping. IMHO the foreign entity needs to drop its
> mappings first. That also ensures that the entities operated
> upon continue to exist.
That's definitely an issue. Maybe having the foreign entity get a
reference to the page and drop it when it unmaps would help ?
> - anon_vma/inode and pte locks are held during callbacks.
So how does that fix the problem of sleeping then ?
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
To: Christoph Lameter <clameter-sJ/iWh9BUns@public.gmane.org>
Cc: Andrew Morton <akpm-3NddpPZAyC0@public.gmane.org>,
Nick Piggin <npiggin-l3A5Bk7waGM@public.gmane.org>,
Andrea Arcangeli <andrea-atKUWr5tajBWk0Htik3J/w@public.gmane.org>,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
steiner-sJ/iWh9BUns@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>,
kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
daniel.blueman-xqY44rlHlBpWk0Htik3J/w@public.gmane.org,
holt-sJ/iWh9BUns@public.gmane.org,
Hugh Dickins <hugh-DTz5qymZ9yRBDgjK7y7TUQ@public.gmane.org>
Subject: Re: [PATCH] export notifier #1
Date: Wed, 23 Jan 2008 10:36:29 +1100 [thread overview]
Message-ID: <1201044989.6807.46.camel@pasglop> (raw)
In-Reply-To: <Pine.LNX.4.64.0801221232040.28197-RYO/mD75kfhx2SFC9UQUAuF7EQX82lMiAL8bYrjMMd8@public.gmane.org>
On Tue, 2008-01-22 at 12:34 -0800, Christoph Lameter wrote:
>
> - Notifiers are called *after* we tore down ptes. At that point pages
> may already have been freed and reused. This means that there can
> still be uses of the page by the user of mmu_ops after the OS has
> dropped its mapping. IMHO the foreign entity needs to drop its
> mappings first. That also ensures that the entities operated
> upon continue to exist.
That's definitely an issue. Maybe having the foreign entity get a
reference to the page and drop it when it unmaps would help ?
> - anon_vma/inode and pte locks are held during callbacks.
So how does that fix the problem of sleeping then ?
Ben.
-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Christoph Lameter <clameter@sgi.com>
Cc: Andrea Arcangeli <andrea@qumranet.com>,
Avi Kivity <avi@qumranet.com>, Izik Eidus <izike@qumranet.com>,
Andrew Morton <akpm@osdl.org>, Nick Piggin <npiggin@suse.de>,
kvm-devel@lists.sourceforge.net, steiner@sgi.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
daniel.blueman@quadrics.com, holt@sgi.com,
Hugh Dickins <hugh@veritas.com>
Subject: Re: [kvm-devel] [PATCH] export notifier #1
Date: Wed, 23 Jan 2008 10:36:29 +1100 [thread overview]
Message-ID: <1201044989.6807.46.camel@pasglop> (raw)
In-Reply-To: <Pine.LNX.4.64.0801221232040.28197@schroedinger.engr.sgi.com>
On Tue, 2008-01-22 at 12:34 -0800, Christoph Lameter wrote:
>
> - Notifiers are called *after* we tore down ptes. At that point pages
> may already have been freed and reused. This means that there can
> still be uses of the page by the user of mmu_ops after the OS has
> dropped its mapping. IMHO the foreign entity needs to drop its
> mappings first. That also ensures that the entities operated
> upon continue to exist.
That's definitely an issue. Maybe having the foreign entity get a
reference to the page and drop it when it unmaps would help ?
> - anon_vma/inode and pte locks are held during callbacks.
So how does that fix the problem of sleeping then ?
Ben.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2008-01-22 23:38 UTC|newest]
Thread overview: 192+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-13 16:24 [PATCH] mmu notifiers #v2 Andrea Arcangeli
2008-01-13 16:24 ` Andrea Arcangeli
2008-01-13 16:24 ` Andrea Arcangeli
2008-01-13 21:11 ` Benjamin Herrenschmidt
2008-01-13 21:11 ` Benjamin Herrenschmidt
2008-01-13 21:11 ` Benjamin Herrenschmidt
2008-01-14 20:02 ` Christoph Lameter
2008-01-14 20:02 ` Christoph Lameter
2008-01-14 20:02 ` Christoph Lameter
2008-01-15 4:28 ` Benjamin Herrenschmidt
2008-01-15 4:28 ` Benjamin Herrenschmidt
2008-01-15 4:28 ` Benjamin Herrenschmidt
2008-01-15 12:44 ` Andrea Arcangeli
2008-01-15 12:44 ` Andrea Arcangeli
2008-01-15 12:44 ` Andrea Arcangeli
2008-01-15 20:18 ` Benjamin Herrenschmidt
2008-01-15 20:18 ` Benjamin Herrenschmidt
2008-01-15 20:18 ` Benjamin Herrenschmidt
2008-01-16 1:06 ` Andrea Arcangeli
2008-01-16 1:06 ` Andrea Arcangeli
2008-01-16 9:01 ` Brice Goglin
2008-01-16 9:01 ` Brice Goglin
2008-01-16 10:19 ` Andrea Arcangeli
2008-01-16 10:19 ` Andrea Arcangeli
2008-01-16 17:42 ` Rik van Riel
2008-01-16 17:42 ` Rik van Riel
2008-01-16 17:42 ` Rik van Riel
2008-01-16 17:48 ` Izik Eidus
2008-01-16 17:48 ` Izik Eidus
2008-01-16 17:48 ` Izik Eidus
2008-01-17 16:23 ` Andrea Arcangeli
2008-01-17 16:23 ` Andrea Arcangeli
2008-01-17 16:23 ` Andrea Arcangeli
2008-01-17 18:21 ` Izik Eidus
2008-01-17 18:21 ` Izik Eidus
2008-01-17 19:32 ` Andrea Arcangeli
2008-01-17 19:32 ` Andrea Arcangeli
2008-01-17 19:32 ` Andrea Arcangeli
2008-01-21 12:52 ` [PATCH] mmu notifiers #v3 Andrea Arcangeli
2008-01-21 12:52 ` Andrea Arcangeli
2008-01-21 12:52 ` Andrea Arcangeli
2008-01-22 2:21 ` Rik van Riel
2008-01-22 2:21 ` Rik van Riel
2008-01-22 2:21 ` Rik van Riel
2008-01-22 14:12 ` [kvm-devel] " Avi Kivity
2008-01-22 14:12 ` Avi Kivity
2008-01-22 14:12 ` Avi Kivity
2008-01-22 14:43 ` [kvm-devel] " Andrea Arcangeli
2008-01-22 14:43 ` Andrea Arcangeli
2008-01-22 14:43 ` Andrea Arcangeli
2008-01-22 20:08 ` [kvm-devel] [PATCH] mmu notifiers #v4 Andrea Arcangeli
2008-01-22 20:08 ` Andrea Arcangeli
2008-01-22 20:08 ` Andrea Arcangeli
2008-01-22 20:34 ` [kvm-devel] [PATCH] export notifier #1 Christoph Lameter
2008-01-22 20:34 ` Christoph Lameter
2008-01-22 20:34 ` Christoph Lameter
2008-01-22 22:31 ` [kvm-devel] " Andrea Arcangeli
2008-01-22 22:31 ` Andrea Arcangeli
2008-01-22 22:31 ` Andrea Arcangeli
2008-01-22 22:53 ` [kvm-devel] " Christoph Lameter
2008-01-22 22:53 ` Christoph Lameter
2008-01-22 22:53 ` Christoph Lameter
2008-01-23 10:27 ` [kvm-devel] " Avi Kivity
2008-01-23 10:27 ` Avi Kivity
2008-01-23 10:27 ` Avi Kivity
2008-01-23 10:52 ` [kvm-devel] " Robin Holt
2008-01-23 10:52 ` Robin Holt
2008-01-23 10:52 ` Robin Holt
2008-01-23 12:04 ` [kvm-devel] " Andrea Arcangeli
2008-01-23 12:04 ` Andrea Arcangeli
2008-01-23 12:34 ` Robin Holt
2008-01-23 12:34 ` Robin Holt
2008-01-23 12:34 ` Robin Holt
2008-01-23 19:48 ` [kvm-devel] " Christoph Lameter
2008-01-23 19:48 ` Christoph Lameter
2008-01-23 19:48 ` Christoph Lameter
2008-01-23 19:58 ` [kvm-devel] " Robin Holt
2008-01-23 19:58 ` Robin Holt
2008-01-23 19:58 ` Robin Holt
2008-01-23 19:47 ` [kvm-devel] " Christoph Lameter
2008-01-23 19:47 ` Christoph Lameter
2008-01-23 19:47 ` Christoph Lameter
2008-01-24 5:56 ` [kvm-devel] " Avi Kivity
2008-01-24 5:56 ` Avi Kivity
2008-01-24 5:56 ` Avi Kivity
2008-01-24 12:26 ` [kvm-devel] " Andrea Arcangeli
2008-01-24 12:26 ` Andrea Arcangeli
2008-01-24 12:26 ` Andrea Arcangeli
2008-01-24 12:34 ` [kvm-devel] " Avi Kivity
2008-01-24 12:34 ` Avi Kivity
2008-01-24 12:34 ` Avi Kivity
2008-01-23 11:41 ` [kvm-devel] " Andrea Arcangeli
2008-01-23 11:41 ` Andrea Arcangeli
2008-01-23 11:41 ` Andrea Arcangeli
2008-01-23 12:32 ` [kvm-devel] " Robin Holt
2008-01-23 12:32 ` Robin Holt
2008-01-23 12:32 ` Robin Holt
2008-01-23 17:33 ` [kvm-devel] " Andrea Arcangeli
2008-01-23 17:33 ` Andrea Arcangeli
2008-01-23 17:33 ` Andrea Arcangeli
2008-01-23 20:27 ` [kvm-devel] " Christoph Lameter
2008-01-23 20:27 ` Christoph Lameter
2008-01-23 20:27 ` Christoph Lameter
2008-01-24 15:42 ` [kvm-devel] " Andrea Arcangeli
2008-01-24 15:42 ` Andrea Arcangeli
2008-01-24 20:07 ` Christoph Lameter
2008-01-24 20:07 ` Christoph Lameter
2008-01-24 20:07 ` Christoph Lameter
2008-01-25 6:35 ` [kvm-devel] " Avi Kivity
2008-01-25 6:35 ` Avi Kivity
2008-01-25 6:35 ` Avi Kivity
2008-01-23 20:18 ` [kvm-devel] " Christoph Lameter
2008-01-23 20:18 ` Christoph Lameter
2008-01-23 20:18 ` Christoph Lameter
2008-01-24 14:34 ` [kvm-devel] " Andrea Arcangeli
2008-01-24 14:34 ` Andrea Arcangeli
2008-01-24 14:34 ` Andrea Arcangeli
2008-01-24 14:41 ` [kvm-devel] " Andrea Arcangeli
2008-01-24 14:41 ` Andrea Arcangeli
2008-01-24 14:41 ` Andrea Arcangeli
2008-01-24 15:15 ` [kvm-devel] " Avi Kivity
2008-01-24 15:15 ` Avi Kivity
2008-01-24 15:15 ` Avi Kivity
2008-01-24 15:18 ` [kvm-devel] " Avi Kivity
2008-01-24 15:18 ` Avi Kivity
2008-01-24 15:18 ` Avi Kivity
2008-01-24 20:01 ` [kvm-devel] " Christoph Lameter
2008-01-24 20:01 ` Christoph Lameter
2008-01-24 20:01 ` Christoph Lameter
2008-01-22 23:36 ` Benjamin Herrenschmidt [this message]
2008-01-22 23:36 ` [kvm-devel] " Benjamin Herrenschmidt
2008-01-22 23:36 ` Benjamin Herrenschmidt
2008-01-23 0:40 ` [kvm-devel] " Christoph Lameter
2008-01-23 0:40 ` Christoph Lameter
2008-01-23 0:40 ` Christoph Lameter
2008-01-23 1:21 ` [kvm-devel] " Robin Holt
2008-01-23 1:21 ` Robin Holt
2008-01-23 1:21 ` Robin Holt
2008-01-23 12:51 ` [kvm-devel] " Gerd Hoffmann
2008-01-23 12:51 ` Gerd Hoffmann
2008-01-23 12:51 ` Gerd Hoffmann
2008-01-23 13:19 ` [kvm-devel] " Robin Holt
2008-01-23 13:19 ` Robin Holt
2008-01-23 13:19 ` Robin Holt
2008-01-23 14:12 ` [kvm-devel] " Gerd Hoffmann
2008-01-23 14:12 ` Gerd Hoffmann
2008-01-23 14:12 ` Gerd Hoffmann
2008-01-23 14:18 ` [kvm-devel] " Robin Holt
2008-01-23 14:18 ` Robin Holt
2008-01-23 14:18 ` Robin Holt
2008-01-23 14:35 ` [kvm-devel] " Gerd Hoffmann
2008-01-23 14:35 ` Gerd Hoffmann
2008-01-23 14:35 ` Gerd Hoffmann
2008-01-23 15:48 ` [kvm-devel] " Robin Holt
2008-01-23 15:48 ` Robin Holt
2008-01-23 15:48 ` Robin Holt
2008-01-23 14:17 ` [kvm-devel] " Avi Kivity
2008-01-23 14:17 ` Avi Kivity
2008-01-23 14:17 ` Avi Kivity
2008-01-24 4:03 ` [kvm-devel] " Benjamin Herrenschmidt
2008-01-24 4:03 ` Benjamin Herrenschmidt
2008-01-24 4:03 ` Benjamin Herrenschmidt
2008-01-23 15:41 ` [kvm-devel] " Andrea Arcangeli
2008-01-23 15:41 ` Andrea Arcangeli
2008-01-23 17:47 ` Gerd Hoffmann
2008-01-23 17:47 ` Gerd Hoffmann
2008-01-23 17:47 ` Gerd Hoffmann
2008-01-24 6:01 ` [kvm-devel] " Avi Kivity
2008-01-24 6:01 ` Avi Kivity
2008-01-24 6:01 ` Avi Kivity
2008-01-24 6:45 ` [kvm-devel] " Jeremy Fitzhardinge
2008-01-24 6:45 ` Jeremy Fitzhardinge
2008-01-23 20:40 ` Christoph Lameter
2008-01-23 20:40 ` Christoph Lameter
2008-01-23 20:40 ` Christoph Lameter
2008-01-24 2:00 ` Enhance mmu notifiers to accomplish a lockless implementation (incomplete) Robin Holt
2008-01-24 2:00 ` Robin Holt
2008-01-24 2:00 ` Robin Holt
2008-01-24 4:05 ` Robin Holt
2008-01-24 4:05 ` Robin Holt
2008-01-24 4:05 ` Robin Holt
2008-01-22 19:28 ` [PATCH] mmu notifiers #v3 Peter Zijlstra
2008-01-22 19:28 ` Peter Zijlstra
2008-01-22 20:31 ` Christoph Lameter
2008-01-22 20:31 ` Christoph Lameter
2008-01-22 20:31 ` Christoph Lameter
2008-01-22 20:31 ` Andrea Arcangeli
2008-01-22 20:31 ` Andrea Arcangeli
2008-01-22 20:31 ` Andrea Arcangeli
2008-01-22 22:10 ` Hugh Dickins
2008-01-22 22:10 ` Hugh Dickins
2008-01-22 22:10 ` Hugh Dickins
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=1201044989.6807.46.camel@pasglop \
--to=benh@kernel.crashing.org \
--cc=akpm@osdl.org \
--cc=andrea@qumranet.com \
--cc=avi@qumranet.com \
--cc=clameter@sgi.com \
--cc=daniel.blueman@quadrics.com \
--cc=holt@sgi.com \
--cc=hugh@veritas.com \
--cc=izike@qumranet.com \
--cc=kvm-devel@lists.sourceforge.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=npiggin@suse.de \
--cc=steiner@sgi.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.