Re: [PATCH 00/31] Swap over NFS -v20

[Peter Zijlstra]

On Sat, 2009-10-10 at 14:06 +0200, Pavel Machek wrote:
> Hi!
> 
> > > One of them
> > > would be the whole VM/net work to just make swap over nbd/iscsi safe.
> > 
> > Getting those two 'fixed' is going to be tons of interesting work
> > because they involve interaction with userspace daemons.
> > 
> > NBD has fairly simple userspace, but iSCSI has a rather large userspace
> > footprint and a rather complicated user/kernel interaction which will be
> > mighty interesting to get allocation safe.
> > 
> > Ideally the swap-over-$foo bits have no userspace component.
> > 
> > That said, Wouter is the NBD userspace maintainer and has expressed
> > interest into looking at making that work, but its sure going to be
> > non-trivial, esp. since exposing PF_MEMALLOC to userspace is a, not over
> > my dead-bodym like thing.
> 
> Well, as long as nbd-server is on separate machine (with real swap),
> safe swapping over network should be ok, without PF_MEMALLOC for
> userspace or similar nightmares, right?

Nope, as soon as the nbd-client looses its connection you're up shit
creek.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/