Hi Fab, On Wed, 2006-09-13 at 12:39, Fabian Tillier wrote: > On 9/13/06, Michael S. Tsirkin <[EMAIL PROTECTED]> wrote: > > Quoting r. Hal Rosenstock <[EMAIL PROTECTED]>: > > > Subject: Re: [openib-general] [PATCH for-2.6.18] IB/cma: option to > > > limitMTU to 1K > > > > > > On Wed, 2006-09-13 at 11:57, Michael S. Tsirkin wrote: > > > > Tavor systems get better performance with 1K MTU. Since there does > > > > not seem to be any way to find out whether the remote system uses Tavor, > > > > add an option to limit the MTU globally. > > > > > > Can't Tavor be determined locally ? > > > > It can, but we need this for remote tavor as well, anyway. > > > > > And couldn't the remote end negotiate the MTU down (if Tavor) as well ? > > > > The way to do this is would be for SA to select 1K MTU if it detects Tavor > > on one side > > and if this does not conflict with MTU selector. > > You can't do this because the SA doesn't have a way to tell if a path > query is going to be used for RC or UD, and IPoIB needs paths with 2K > MTU.
Are you referring to IPoIB-CM ? The patch appears to be for the SA PR request prior to the CM REQ. I don't think it affects IPoIB SA PR requests. -- Hal > Would be nice if the CM REP would allow the MTU to be negotiated down. > There is plenty of space in the REP if we were to use up some of the > reserved fields. > > - Fab _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
