On Wed, 06 Jun 2007 16:56:02 -0700 (PDT) David Miller <[EMAIL PROTECTED]> wrote:
> From: jamal <[EMAIL PROTECTED]> > Date: Wed, 06 Jun 2007 19:35:46 -0400 > > > There is no potential for parallelizing on transmit that i can think of. > > Dave, please explain it slowly so i can understand it. > > > > There is huge potential for parallelizing on receive. But i am certainly > > missing the value in the transmit. > > I gave an example in another response, you have N processes > queueing up data for TCP or UDP or whatever in parallel on > different cpus, all going out the same 10gbit device. > > All of them enter into ->hard_start_xmit(), and thus all of them try > to take the same netdev->tx_lock > > If they have multiple TX queues, independantly programmable, that > single lock is stupid. > > We could use per-queue TX locks for such hardware, but we can't > support that currently. There could be bad packet reordering with this (like some SMP routers used to do). -- Stephen Hemminger <[EMAIL PROTECTED]> - 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
