Herbert Xu <[EMAIL PROTECTED]> wrote on 08/08/2007 07:12:47 PM: > On Wed, Aug 08, 2007 at 03:49:00AM -0700, David Miller wrote: > > > > Not because I think it obviates your work, but rather because I'm > > curious, could you test a TSO-in-hardware driver converted to > > batching and see how TSO alone compares to batching for a pure > > TCP workload? > > You could even lower the bar by disabling TSO and enabling > software GSO.
I will try with E1000 (though I didn't see improvement when I tested a long time back). The difference I expect is that TSO would help with large packets and not necessarily small/medium packets and not definitely in the case of multiple different skbs (as opposed to single large skb) getting queue'd. I think these are two different workloads. > > I personally don't think it will help for that case at all as > > TSO likely does better job of coalescing the work _and_ reducing > > bus traffic as well as work in the TCP stack. > > I agree. I suspect the bulk of the effort is in getting > these skb's created and processed by the stack so that by > the time that they're exiting the qdisc there's not much > to be saved anymore. However, I am getting a large improvement for IPoIB specifically for this same case. The reason - batching will help only when queue gets full and stopped (and to a lesser extent if tx lock was not got, which results in fewer amount of batching that can be done). thanks, - KK - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
