On Wed, 2005-07-12 at 13:06 -0800, David S. Miller wrote: > From: jamal <[EMAIL PROTECTED]> > Date: Wed, 07 Dec 2005 15:23:57 -0500 > > > I am no longer sure that your results on copybreak for host bound > > packets can be trusted anymore. All your copybreak was doing was making > > the prefetch look good according to my tests. > > For the host bound case, copybreak is always a way due to how > socket buffer accounting works. If you use a 1500 byte SKB for > 64 bytes of data, this throws off all of the socket buffer > accounting because you're consuming more of the socket limit > per byte of data than necessary.
Ok, this does make logical sense for host bound packets - it will be of a bigger problem on a 10Gige server (receiving a lot of ACKs) than on a setup with an e1000 though. On the prefetch, i think would you agree now that it is problematic? I just showed that if i changed the cycle of execution between the moment the prefecth gets issued to the moment the data gets used we get different performance results. I think there is value for prefetch - just not the way the current patch has it. Something less adventorous as suggested by Robert would make a lot more sense. I just lost the hardware - but will have another window tommorow to validate some of Roberts tests. cheers, jamal - 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
