Re: [RFC][PATCH] Add do_not_call_when_idle option to timer and workqueue

[Andrew Morton <akpm@osdl.org>]

On Wed, 22 Nov 2006 09:13:24 -0800
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> wrote:

> On Tue, Nov 21, 2006 at 06:11:14PM -0800, Andrew Morton wrote:
> > On Tue, 21 Nov 2006 16:28:45 -0800
> > Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> wrote:
> > 
> > > 
> > >  struct timer_list {
> > >  	struct list_head entry;
> > >  	unsigned long expires;
> > > @@ -16,6 +18,7 @@
> > >  	unsigned long data;
> > >  
> > >  	struct tvec_t_base_s *base;
> > > +	int	flags;
> > >  #ifdef CONFIG_TIMER_STATS
> > 
> > Adding a new field to the timer_list is somewhat of a hit - this is going
> > to make an awful lot of data structures a bit larger.  Some of which we
> > allocate a large number of.
> > 
> > I think we could justfy getting nasty and using the LSB of
> > timer_list.function for this..
> 
> That is a clever idea... Is that going to work in all architectures with all
> compiler flags?

Don't know.  Possibly not.  Other options are list.next, list.prev and
base.  None of them are pleasant.