Device polling

Jon Noack noackjr at
Mon Jun 14 07:56:55 GMT 2004

On 06/14/04 02:24, Luigi Rizzo wrote:
> On Mon, Jun 14, 2004 at 01:36:58AM +0300, Ruslan Ermilov wrote:
>> On Sun, Jun 13, 2004 at 04:07:13PM -0500, Jon Noack wrote:
>>> On 06/13/04 13:13, Ruslan Ermilov wrote:
>>>> On Sun, Jun 13, 2004 at 01:07:28PM -0500, Jon Noack wrote:
>>>>> I just tested this on my SMP all-in-one home server (Web,
>>>>> Mail,
> ...
>> Bump HZ.  If you were using the 64-bit PCI I'd say bump it to 5000,
>> but since you're using 32-bit PCI, bumping it that high just
>> doesn't make sense, so raise it up to 2000-3000.
>> Set kern.polling.idle_poll=1.
>      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> this is the part that cannot possibly work with SMP,
> and that seems to have problem with current even on !SMP

Well, in limited testing it doesn't seem to have any effect.

After a lot of tweaking, polling on my SMP box appears to lower 
throughput by ~50Mbps (~370 down to ~320).  It does improve performance 
on my single-processor machines, though.  Again, if I have more time 
I'll give the netperf patches a shot.


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