Re: intermittant petabyte usage reported with broadcom nic

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 2 Apr 2007 11:43:19 +1000 CaT <[email protected]> wrote:
>  
> I take minute by minute snapshots of network traffic by sampling
> /proc/net/dev and most of the time everything works fine. Occasionally
> though I get petabyte byte traffic and corresponding packet traffic.

We were able to reproduce the problem and confirmed that it was a DMA
problem of the statistics block.  About once an hour on average, wrong
counter values will be DMA'ed to host memory.  Luckily, the DMA write
stays within the intended address range so it will not corrupt other
parts of memory.  Other types of DMA including traffic and buffer
descriptors are not affected.

If you happen to be reading /proc/net/dev within a second after the DMA
corruption, you'll see bogus counters.  One second later and until the
next bad DMA, the counters will be normal again.

We are considering ways to workaround the problem.  Thanks.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux