From: Rusty Russell <rusty@rustcorp.com.au>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: netdev@vger.kernel.org, Max Krasnyansky <maxk@qualcomm.com>,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] tun: vringfd xmit support.
Date: Sun, 20 Apr 2008 00:41:43 +1000 [thread overview]
Message-ID: <200804200041.43969.rusty@rustcorp.com.au> (raw)
In-Reply-To: <20080418120634.986e30f1.akpm@linux-foundation.org>
On Saturday 19 April 2008 05:06:34 Andrew Morton wrote:
> On Sat, 19 Apr 2008 01:15:15 +1000 Rusty Russell <rusty@rustcorp.com.au>
wrote:
> > > What is the maximum numbet of pages which an unpriviliged user can
> > > concurrently pin with this code?
> >
> > Since only root can open the tun device, it's currently OK. The old code
> > kmalloced and copied: is there some mm-fu reason why pinning userspace
> > memory is worse?
>
> We generally try to avoid it - it allows users to dos the box.
My question is: is pinning a page worse than allocating a (kernel) page in
some way?
Cheers,
Rusty.
next prev parent reply other threads:[~2008-04-19 14:43 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-18 4:33 [PATCH 0/5] High-speed tun receive and xmit Rusty Russell
2008-04-18 4:35 ` [PATCH 1/5] virtio: put last_used and last_avail index into ring itself Rusty Russell
2008-04-18 4:39 ` [PATCH 2/5] /dev/vring: simple userspace-kernel ringbuffer interface Rusty Russell
2008-04-18 4:41 ` [PATCH 3/5] /dev/vring limit and base ioctls Rusty Russell
2008-04-18 4:42 ` [PATCH 4/5] tun: vringfd receive support Rusty Russell
2008-04-18 4:43 ` [PATCH 5/5] tun: vringfd xmit support Rusty Russell
2008-04-18 11:31 ` Andrew Morton
2008-04-18 15:15 ` Rusty Russell
2008-04-18 16:24 ` Ray Lee
2008-04-18 19:06 ` Andrew Morton
2008-04-19 14:41 ` Rusty Russell [this message]
2008-04-19 17:51 ` Andrew Morton
2008-04-19 1:54 ` Andrew Morton
2008-04-18 11:46 ` pradeep singh rautela
2008-04-18 14:25 ` Ray Lee
2008-04-18 18:01 ` pradeep singh rautela
2008-04-18 11:18 ` [PATCH 2/5] /dev/vring: simple userspace-kernel ringbuffer interface Andrew Morton
2008-04-18 14:32 ` Rusty Russell
2008-04-18 18:59 ` Andrew Morton
2008-04-18 19:38 ` Michael Kerrisk
2008-04-19 16:41 ` Rusty Russell
2008-04-20 0:16 ` David Miller
2008-04-19 15:02 ` Jonathan Corbet
2008-04-19 10:22 ` Evgeniy Polyakov
2008-04-19 16:05 ` Rusty Russell
2008-04-19 16:33 ` Evgeniy Polyakov
2008-04-19 16:45 ` Rusty Russell
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