On Mon, Aug 07, 2006 at 03:03:33PM -0400, jamal wrote:
> On Mon, 2006-07-08 at 20:47 +0200, Edgar E. Iglesias wrote:
>
> > I think we are out of sync :)
>
> Imagine that, eh? ;->
>
> > My, fault I haven't been clear enough.
> >
>
> Not just your transmit but also my receive is at fault ;-> (aka, I may
> not be listening as well as i should). Now two machines or CPUs you
> would think wont have this problem since they dont possess minds;->
>
> > First of all, I don't think the patch with jamal undefined has any
> > problems. I
> > assumed wrongly from the start that you somehow wanted that part to go in
> > aswell, sorry about that. As you say, the flow goes just as before.
> >
> > Now, with jamal defined, I only see e1000_prune_tx_ring beeing called if
> > fdesc < tx_ring->prunet or fdesc < tx_ring->waket.
>
> Ok, thats the code that has been commented out, no? i.e there is no
> fdesc otherwise.
Exactly.
>
> > In other words, the freing
> > of skbs is dependant on external events that might not become true if the
> > host is quiet. Skb's could end up sitting on the ring indefinitely.
> >
>
> Yes, this has _always_ been true. In the patch i posted it merely
> converted things, example:
>
> -#define E1000_TX_WEIGHT 64
> - /* weight of a sort for tx, to avoid endless transmit
> cleanup */
> - if (count++ == E1000_TX_WEIGHT) break;
> + /* avoid endless transmit cleanup */
> + if (count++ == tx_ring->prunet) break;
>
> As you can see E1000_TX_WEIGHT threshold exists today and you are right
> if no TX interupts, packet arrivals or scheduled wakes happen the that
> descriptor that was not pruned will sit there forever (which is a bad
> thing for TCP). Are we in sync?
Yep :)
> If yes, what is the likelihood they will sit there forever? I think
> perhaps some TX interupts will happen, no?
with jamal undefined, absolutely. With jamal defined, TX interrupts will come
but I couldnt find a way into e1000_prune_tx_ring unless fdesc met the
conditions. Correct?
Best regards
--
Programmer
Edgar E. Iglesias <[EMAIL PROTECTED]> 46.46.272.1946
-
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
