Re: [PATCH] make refrigerator cold

[Stephen Hemminger <shemminger@vyatta.com>]

On Wed, 23 Sep 2009 01:13:20 +0200
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> 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

Sure, any of the possibilities works, you choose.