On Tue, 09 Oct 2007, David Miller wrote:
> From: jamal <[EMAIL PROTECTED]>
> Date: Tue, 09 Oct 2007 17:56:46 -0400
>
> > if the h/ware queues are full because of link pressure etc, you drop. We
> > drop today when the s/ware queues are full. The driver txmit lock takes
> > place of the qdisc queue lock etc. I am assuming there is still need for
> > that locking. The filter/classification scheme still works as is and
> > select classes which map to rings. tc still works as is etc.
>
> I understand your suggestion.
>
> We have to keep in mind, however, that the sw queue right now is 1000
> packets. I heavily discourage any driver author to try and use any
> single TX queue of that size. Which means that just dropping on back
> pressure might not work so well.
>
> Or it might be perfect and signal TCP to backoff, who knows! :-)
I can't remember the details anymore, but for 10-GigE, I have encountered
cases where I was able to significantly increase TCP performance by
increasing the txqueuelen to 10000, which is the setting I now use for
any 10-GigE testing.
-Bill
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