[vortex-bug] Tx int. mitigation

Bogdan Costescu Bogdan.Costescu@IWR.Uni-Heidelberg.De
Thu, 14 Dec 2000 18:59:33 +0100 (CET)

On Thu, 14 Dec 2000, Donald Becker wrote:

> We need some way to scavenge Tx skbuffs in a timely manner, even if we are
> not receiving packets.

I see several solutions:
- do it while processing other (mostly Rx) interrupts
- use the Countdown timer to generate an interrupt periodically, but not
very fast, say, once a second
- use a timer/kernel thread to come back and check for packets in the Tx

> The protocol layer uses the skbuff-is-free information....

How precise the timing should be ? Is it OK to keep the skbuff alocated
one second (or so) more after it was transmitted ?

> ...  Leaving already
> transmitted skbuffs on the transmit queue will cause mysterious performance
> problems.

The upper levels are a bit of mistery to me. Can you elaborate on this ?

> Additional issue: Debugging is easier if the Tx statistics are correct.

If we do it right, we don't need debugging 8-))

Still, my original question about Tx mitigation remained unanswered...


Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu@IWR.Uni-Heidelberg.De