Re: [PATCH] init: skip calibration delay if previously done

[David Daney]

On 06/03/2011 02:00 PM, Andrew Morton wrote:
> On Tue, 24 May 2011 16:19:06 -0700
> Sameer Nanda<snanda@xxxxxxxxxxxx>  wrote:
>
> > For each CPU, do the calibration delay only once. For subsequent calls,
> > use the cached per-CPU value of loops_per_jiffy.
> >
> > This saves about 200ms of resume time on dual core Intel Atom N5xx based
> > systems. This helps bring down the kernel resume time on such systems from
> > about 500ms to about 300ms.
> >
> > Signed-off-by: Sameer Nanda<snanda@xxxxxxxxxxxx>
> > ---
> >   init/calibrate.c |   10 +++++++++-
> >   1 files changed, 9 insertions(+), 1 deletions(-)
> >
> > diff --git a/init/calibrate.c b/init/calibrate.c
> > index 76ac919..47d3408 100644
> > --- a/init/calibrate.c
> > +++ b/init/calibrate.c
> > @@ -183,11 +183,18 @@ recalibrate:
> >   	return lpj;
> >   }
> >
> > +DEFINE_PER_CPU(unsigned long, cpu_loops_per_jiffy) = { 0 };
> > +
> >   void __cpuinit calibrate_delay(void)
> >   {
> >   	static bool printed;
> > +	int this_cpu = smp_processor_id();
> >
> > -	if (preset_lpj) {
> > +	if (per_cpu(cpu_loops_per_jiffy, this_cpu)) {
> > +		loops_per_jiffy = per_cpu(cpu_loops_per_jiffy, this_cpu);
> > +		pr_info("Calibrating delay loop (skipped) "
> > +				"already calibrated this CPU previously.. ");

That wording seems a little redundant, and there are two '.' at the end.

How about:
s/"already calibrated this CPU previously.. "/", this CPU previously 
calibrated."/

David Daney
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