Re: [PATCH] Network Checksum Removal

[Bin Ren <bin.ren@gmail.com>]

Start from fresh again. The same weird symptoms.

- Bin

On 5/23/05, Bin Ren <bin.ren@gmail.com> wrote:
> I'm using bridge and stock scripts. I start to doubt it's caused csum
> offloading, as I'm seeing some weird things. (1) it's possible to do
> interdomain iperf, which binds to ports > 1024 (2) ssh and nfs don't
> work. In both cases, dom0 is the server, dom1 is the client. tcpdump
> on dom0 doesn't show any incoming packets from dom1.
> 
> I'm recompiling everything again.
> 
> Cheers,
> Bin
> 
> On 5/23/05, Andrew Theurer <habanero@us.ibm.com> wrote:
> > On Monday 23 May 2005 10:31, Bin Ren wrote:
> > > It seems to break the interdomain ssh and nfs on my machine. Digging
> > > for reasons.
> >
> > Are you using bridge or network model?
> > >
> > > - Bin
> > >
> > > On 5/23/05, Andrew Theurer <habanero@us.ibm.com> wrote:
> > > > > I've checked in a modified version of your patch that hopefully
> > > > > deals with propagating checksum information in both directions
> > > > > across a virtual bridge or router. I replaced your skb flags with
> > > > > two new ones -- proto_csum_blank and proto_csum_valid.
> > > > >
> > > > > The former indicates that the protocol-level checksum needs
> > > > > filling in. This is not a problem for local processing, but the
> > > > > flag is picked up before sending to a physical interface and
> > > > > fixed up.
> > > > >
> > > > > The latter indicates that the proto-level checksum has been
> > > > > validated since arrival at localhost (*or* that the packet
> > > > > originated from a domU on localhost). This flag survives crossing
> > > > > a bridge/router so we can trust it when deciding if checksum
> > > > > validation is required.
> > > > >
> > > > > I'll push the patch to the bkbits repository just as soon as
> > > > > bkbits rematerialises. :-)
> > > > >
> > > > > If you have any performance or stress tests that you were using
> > > > > to test checksum offloading, it would be great to find out how
> > > > > they perform on the checked-in version!
> > > >
> > > > Now that BK is up, I'll run some netperf tests before/after that
> > > > changeset and see what we get.
> > > >
> > > > -Andrew
> > > >
> > > > _______________________________________________
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> >
> >
>