Re: Re: [RFC 5/6]clean cpu state after hotremove CPU

[Nathan Lynch <ntl-e+AXbWqSrlAAvxtiuMwx3w@public.gmane.org>]

Hi Nigel!

On Tue, Apr 05, 2005 at 08:14:25AM +1000, Nigel Cunningham wrote:
> 
> On Tue, 2005-04-05 at 01:33, Nathan Lynch wrote:
> > > Yes, exactly. Someone who understand do_exit please help clean up the
> > > code. I'd like to remove the idle thread, since the smpboot code will
> > > create a new idle thread.
> > 
> > I'd say fix the smpboot code so that it doesn't create new idle tasks
> > except during boot.
> 
> Would that mean that CPUs that were physically hotplugged wouldn't get
> idle threads?

No, that wouldn't work.  I am saying that there's little to gain by
adding all this complexity for destroying the idle tasks when it's
fairly simple to create num_possible_cpus() - 1 idle tasks* to
accommodate any additional cpus which may come along.  This is what
ppc64 does now, and it should be feasible on any architecture which
supports cpu hotplug.


Nathan

* num_possible_cpus() - 1 because the idle task for the boot cpu is
  created in sched_init.


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click