On Sun, Mar 22, 2015 at 11:21:50AM +0200, Yuval Shaia wrote: > On Sun, Mar 15, 2015 at 05:16:16PM +0200, Yuval Shaia wrote: > > Hi, > > I didn't got any further comments on this one. > > Any idea why SG in CM is un-welcome? > By mistake I sent a private mail only. > Cc: Roland Dreier <roland@xxxxxxxxxx> > Cc: Sean Hefty <sean.hefty@xxxxxxxxx> > Cc: Hal Rosenstock <hal.rosenstock@xxxxxxxxx> > > Your advice would be very appreciated. I haven't looked in detail at the patch, but in principle, using S/G when ever possible should be the default, even if this creates a performance regression. It is well known that high order allocations are problematic in Linux and should be avoided, and I also have seen systems blow up because of high order IPoIB allocations. That said, there may be cases where S/G is not possible, you should try and get Mellanox to comment if all their offloads work on all their cards when S/G is used. Work may be required to resolve any of these constraints. I'd like to belive there is some reason why we've been doing high order allocations for so many years. FWIW, I would probably choose to default S/G over any other offload acceleration. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
