Re: [PATCH -mm] Allow selective freezing of the system for different events

[Gautham R Shenoy <ego@in.ibm.com>]

On Fri, Apr 27, 2007 at 11:22:22PM -0700, Andrew Morton wrote:
> On Sat, 28 Apr 2007 07:04:46 +0530 Gautham R Shenoy <ego@in.ibm.com> wrote:
> 
> > This patch
> > * Provides an interface to selectively freeze the system for different events.
> > * Allows tasks to exempt themselves or other tasks from specific freeze
> >   events.
> > * Allow nesting of freezer calls. For eg:
> > 
> > 	freeze_processes(EVENT_A);
> > 	/* Do something with respect to event A */
> > 	.
> > 	.
> > 	.
> > 	freeze_processes(EVENT_B);
> > 	/* Do something with respect to event B */
> > 	.
> > 	.
> > 	.
> > 	thaw_processes(EVENT_B);
> > 	.
> > 	.
> > 	.
> > 	thaw_processes(EVENT_B);
> > 
> > This type of behaviour would be required when cpu hotplug would start
> > using the process freezer, where EVENT_A would be SUSPEND and EVENT_B
> > would be HOTPLUG_CPU.
> > 
> > This patch applies on the top of 2.6.21-rc7-mm2 + Rafael's freezer
> > changes from http://lkml.org/lkml/2007/4/27/302.
> 
> I think I'll duck this.  We have more than enough kthread/freezer/etc work
> queued for 2.6.22. 

Sure, not a problem :-)

I just wanted to get a sense, if this was a right way to do it. 
Besides, I am plannning to send it again once I port the cpuhotplug
patches on top of all these changes and get some satisfactory numbers.

> Let's please for now concentrate on reviewing and
> testing the existing changes.  Once that has all landed and settled in,
> let's start thinking about the next round.
> 

Ok.

Thanks and Regards
gautham.
-- 
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"