[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1169025638.22935.114.camel@twins>
Date: Wed, 17 Jan 2007 10:20:38 +0100
From: Peter Zijlstra <a.p.zijlstra@...llo.nl>
To: Pavel Machek <pavel@....cz>
Cc: linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
linux-mm@...ck.org, David Miller <davem@...emloft.net>
Subject: Re: [PATCH 0/9] VM deadlock avoidance -v10
On Wed, 2007-01-17 at 10:12 +0100, Pavel Machek wrote:
> Hi!
>
> > These patches implement the basic infrastructure to allow swap over networked
> > storage.
> >
> > The basic idea is to reserve some memory up front to use when regular memory
> > runs out.
> >
> > To bound network behaviour we accept only a limited number of concurrent
> > packets and drop those packets that are not aimed at the connection(s) servicing
> > the VM. Also all network paths that interact with userspace are to be avoided -
> > e.g. taps and NF_QUEUE.
> >
> > PF_MEMALLOC is set when processing emergency skbs. This makes sense in that we
> > are indeed working on behalf of the swapper/VM. This allows us to use the
> > regular memory allocators for processing but requires that said processing have
> > bounded memory usage and has that accounted in the reserve.
>
> How does it work with ARP, for example? You still need to reply to ARP
> if you want to keep your ethernet connections.
ETH_P_ARP is fully processed (under PF_MEMALLOC).
ETH_P_IP{,V6} starts to drop packets not for selected sockets
(SOCK_VMIO) and processes the rest (under PF_MEMALLOC) with limitations;
the packet may never depend on user-space to complete processing.
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists