Re: [PATCH] sky2: Use deferrable timer for watchdog

[Krzysztof Oledzki]

On Thu, 20 Dec 2007, Parag Warudkar wrote:

> On Dec 20, 2007 2:22 PM, Kok, Auke <auke-jan.h.kok@xxxxxxxxx> wrote:
> > ok, that's just bad and if there's no user-defineable limit to the deferral I
> > definately don't like this change.
> >
> > Can I safely assume that any irq will cause all deferred timers to run?
>
> I think even other causes for wakeup like process related ones will
> cause the CPU to go busy and run the timers.
> This, coupled with the fact that no one is yet able to reach 0 wakeups
> per second makes it pretty unlikely that deferrable timers will be
> deferred indefinitely.
>
> > If this is the case then for e1000 this patch is still OK since the watchdog needs
> > to run (1) after a link up/down interrupt or (2) to update statistics. Those
> > statistics won't increase if there is no traffic of course...
>
> I think it is reasonable for Network driver watchdogs to use a
> deferrable timer - if the machine is 100% IDLE there is no one needing
> the network to be up.

Please note tha being connected to a network does not only mean to send 
but also to receive.

Best regards,

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