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 [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to