Hi Dave, This change will not change existing behavior in case there are packets in the queue, it will return -1 each time as does the original code. But when there are no packets, the original qdisc_restart returns -1 and the caller will unnecessarily call qdisc_restart which branches to the bottom and returns 0 (qlen). This call can be avoided if we had returned 0 in the previous iteration. Branching to the bottom cannot be done since it breaks the "packets present" case, as it will return a positive number and the caller will assume that the queue is throttled.
thanks, - KK David Miller <[EMAIL PROTECTED]> wrote on 05/09/2007 07:35:06 AM: > From: Krishna Kumar <[EMAIL PROTECTED]> > Date: Tue, 08 May 2007 13:01:32 +0530 > > > Optimize return value of qdisc_restart so that it is not called an > > extra time if there are no more packets on the queue to be sent out. > > It is also not required to check for gso_skb (though the lock is > > dropped) since another cpu which added this would have done a > > netif_schedule. > > > > Patch against net-2.6.22.git > > > > Signed-off-by: Krishna Kumar <[EMAIL PROTECTED]> > > <0 return value here means that the queue is not empty, and the device > is throttled. If you want to do this, just branch down to the end of > the function which asserts that q->q.qlen is not negative, and returns > it. > > That will achieve the right effect. > > But I'm not so sure about this idea, I have this strange feeling that > we do things this way for a reason... Hmmm... - 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
