Re: [PATCH] XPC heartbeat timer function must run on CPU 0

[Simon Horman <horms@verge.net.au>]

On Wed, Nov 14, 2007 at 03:12:38PM -0600, Robin Holt wrote:
> On Wed, Nov 14, 2007 at 12:49:14PM -0800, Simon Horman wrote:
> > On Thu, Nov 08, 2007 at 06:11:19AM -0600, Dean Nelson wrote:
> > > On Wed, Nov 07, 2007 at 08:26:59AM -0800, Luck, Tony wrote:
> > > > > Currently, XPC's heartbeat timer function runs on whatever CPU modprobe/insmod
> > > > > ran on when XPC was started. To avoid the heartbeat from being delayed for
> > > > > long periods the timer function must run on CPU 0.
> > > > 
> > > > Does Altix allow hot remove of cpu0?  If so, then you have a problem.
> > > 
> > > At this time Altix does not support hot remove of cpu0, but it is something
> > > currently being worked on. At the time that feature is ready then this
> > > code would indeed need to be modified. In the meantime, we have an existing
> > > customer in need of a fix.
> > 
> > Kdump will run the second (crash) kernel on whatever CPU the crash
> > occurs on, so its quite possible for cpu 0 not to exist in the
> > second kernel. Would this be a problem for this code?
> 
> Wouldn't that cpu appear to the new OS instance as cpu0?  If so, then
> it should not be an issue.

No, I don't believe that it does.
I can try and test this theory if it helps.
Perhaps my mind is corrupted by x86 thoughts.

-- 
Horms, California Edition