Re: init_timer_deferrable conversion

From: Parag Warudkar
Date: Mon Dec 17 2007 - 12:48:21 EST


On Dec 17, 2007 12:00 PM, Stephen Hemminger
<shemminger@xxxxxxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > a) drivers/net/sky2.c - watchdog_timer. This was showing up high on
> > > > Powertop's list of things that cause routine wakeups from idle. After
> > > > converting to init_timer_deferrable() the wakeups went down and this one
> > > > no longer shows up in powertop's list. 25% reduction.
>
> This surprises me because it is a 1 hz timer and uses round_jiffies() in
> the current kernel.

I am using the current git and I already have low wakeups per second
to begin with - 5-7 and out of that 25% are attributed to sky2. Not
sure if that matches up with the 1 hz + round_jiffies() logic.

But is it conceptually ok to make this deferrable? I suppose yes as
it's just a watchdog that checks if the link is up and delaying that
would not make a difference?

Thanks
Parag
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