> Quoting James Lentini <[EMAIL PROTECTED]>: > Subject: Re: [PATCHv2] IB/ipoib: S/G and HW checksum support > > > > On Tue, 4 Sep 2007, Michael S. Tsirkin wrote: > > > > Quoting James Lentini <[EMAIL PROTECTED]>: > > > Subject: Re: [PATCHv2] IB/ipoib: S/G and HW checksum support > > > > > > > > > > > > On Tue, 4 Sep 2007, Michael S. Tsirkin wrote: > > > > > > > > Quoting James Lentini <[EMAIL PROTECTED]>: > > > > > Subject: Re: [PATCHv2] IB/ipoib: S/G and HW checksum support > > > > > > > > > > > > > > > > > > > > On Tue, 4 Sep 2007, Jason Gunthorpe wrote: > > > > > > > > > > > On Tue, Sep 04, 2007 at 12:11:33PM +0300, Michael S. Tsirkin wrote: > > > > > > > > > > > > > I know some people find this approach controversial, > > > > > > > but from my perspective, this is not worse than e.g. > > > > > > > SDP which does not have SW checksums pretty much by design. > > > > > > > > > > > > This would be alot better in my mind of the option was negotiated as > > > > > > part of the CM setup process. Otherwise this becomes a network wide > > > > > > all or nothing kind of feature.. > > > > > > > > > > > > What if the RXing Linux IB side is acting as a forwarder to > > > > > > ethernet? > > > > > > It will forward corrupt packets if this option is set, right? > > > > > > > > > > So this break all gateway devices? > > > > > > > > It won't. The gateway will calculate the checksums. > > > > > > > > > How would packets be routed with this change? > > > > > > > > As usual. > > > > > > A Linux system setup as a router with an IPoIB interface and an > > > Ethernet interface will work if this feature is turned on? > > > > I am yet to test this setup, but yes, it should. > > I has this scenario in mind: > > A ------- B ------- C > IPoIB Eth > > A and C are Linux hosts, B is a Linux host setup as a router. > > If the link between A and B has this checksum change turned on, then > then TCP connections between A anc C will fail with TCP checksum > errors.
A to C communication will work if B goes over A->C packets and fills in the transport checksums before sending the packet to C. > Technically an IPoIB network with these changes can route IP packets > to other networks, I know. Hopefully this will keep working with hw_csum bit set. > but with the missing transport layer checksums > the contents are unintelligible. This is not what I'm aiming for :). In this setup, the transport checksums could be calculated by B. I haven't tested this conf yet, hopefully, this can be made to work without changes to linux networking stack, by assigning CHECKSUM_PARTIAL to the skb. -- MST _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
