On Thu, 2007-10-05 at 04:55 -0700, David Miller wrote: > From: Herbert Xu <[EMAIL PROTECTED]> > Date: Thu, 10 May 2007 21:50:39 +1000 >
> T_SCHED]: Rationalise return value of qdisc_restart > > > > The current return value scheme and associated comment was invented > > back in the 20th century when we still had that tbusy flag. Things > > have changed quite a bit since then (even Tony Blair is moving on > > now, not to mention the new French president). > > > > All we need to indicate now is whether the caller should continue > > processing the queue. Therefore it's sufficient if we return 0 if > > we want to stop and non-zero otherwise. > > > > This is based on a patch by Krishna Kumar. > > > > Signed-off-by: <[EMAIL PROTECTED]> > > Fair enough, patch applied :-) Ok, see if this makes sense: CPU0 CPU1 (holding qdisc running) . | . | . + grab qlock . | . | deq pkt . + release qlock . + grab txlock . | send pkt . + release txlock . + grab qlock has pktX | (NEW: qlen = 0); return 0 instead of -1 waiting for qlock + release qlock + grab qlock | | + find that return code is 0 | enq pkt X + release qdisc running | | + release qlock | ==> outta here pkt X is stuck unless some event happens such as a new pkt arrival. In other words it sits there for an indeterminate period. 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
