Re: [PATCH] make refrigerator cold

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday 22 September 2009, Stephen Hemminger wrote:
> On Tue, 22 Sep 2009 21:54:09 +0200
> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
> 
> > On Tuesday 22 September 2009, Stephen Hemminger wrote:
> > > By marking it cold, then the code path in kernel thread 
> > > usage of try_to_freeze() that is normally used be
> > > selected.
> > 
> 
> In the code for try_to_freeze(), for optimization, it might
> help to tell the compiler to not favor the code path where
> the refigrator is being called.
> 
> Another way to do the same thing would be to do.
>    if (unlikely(freezing(current))) {
> 	refrigerator();
> 	return 1;
>    } else
> 	return 0;
> 
> or build unlikely into the freezing function (see need_resched).
> 
> I saw this by trying to minimize the number of intstructions
> in pktgen which is a special case.

OK, thanks.

Will it be fine with you if I add the patch to the suspend-2.6 tree with the
above information in the changelog?

Rafael