Re: ksoftirqd uses 99% CPU triggered by network traffic (maybeRLT-8139 related)

[Pasi Sjoholm]

I forgot to mention that it was quite hard to crash the driver with that 
/* Clear out errors and receive interrupts */-patch. Took about 15minutes 
everytime, when normally it takes about 2mins.

On Mon, 2 Aug 2004, Pasi Sjoholm wrote:

> With both patch applied and RTL8139DEBUG = 1 I couldn't make the driver 
> crash but without DEBUG it did crash. I assume that it has something to 
> with fact that syslog did take so much io-bandwidth. (a couple of minutes log 
> was ~1GB =))
> 
> But without: 
> 
> --
> @@ -2024,17 +2024,17 @@ static int rtl8139_rx(struct net_device
> 
>                 cur_rx = (cur_rx + rx_size + 4 + 3) & ~3;
>                 RTL_W16 (RxBufPtr, (u16) (cur_rx - 16));
> +       }
> 
> -               /* Clear out errors and receive interrupts */
> -               status = RTL_R16 (IntrStatus) & RxAckBits;
> -               if (likely(status != 0)) {
> -                       if (unlikely(status & (RxFIFOOver | RxOverflow))) 
> {
> -                               tp->stats.rx_errors++;
>  -                               if (status & RxFIFOOver)
> -                                       tp->stats.rx_fifo_errors++;
> -                       }
> -                       RTL_W16_F (IntrStatus, RxAckBits);
> +       /* Clear out errors and receive interrupts */
> +       status = RTL_R16 (IntrStatus) & RxAckBits;
> +       if (likely(status != 0)) {
> +               if (unlikely(status & (RxFIFOOver | RxOverflow))) {
> +                       tp->stats.rx_errors++;
> +                       if (status & RxFIFOOver)
> +                               tp->stats.rx_fifo_errors++;
>                 }
> +               RTL_W16_F (IntrStatus, RxAckBits);
>         }
> 
>   done:
> --
> 
> the driver crashed... even with debug-option was turned on.
> Everytime the ksoftirqd started to take cpu-time there were this line in 
> the logs:

-
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