Re: [PATCH V2] Change ACPI IPMI support to "default y"

[Russ Anderson <rja@sgi.com>]

On Thu, Feb 20, 2014 at 09:00:48PM +0000, Matthew Garrett wrote:
> On Thu, 2014-02-20 at 14:59 -0600, Russ Anderson wrote:
> > On Thu, Feb 20, 2014 at 08:46:04PM +0000, Matthew Garrett wrote:
> > > On Thu, 2014-02-20 at 14:40 -0600, Russ Anderson wrote:
> > > 
> > > > This is also a problem for systems with functional BMCs.  Our
> > > > large cluster systems do all IPMI traffic (monitoring) through
> > > > a system controller back door.  We do not want the kernel
> > > > doing IPMI commands on those systems.
> > > 
> > > Why not?
> > 
> > Because some customers want to use cpu cycles for their
> > application and let the ipmi monitoring go on through
> > the system controller network.
> 
> Why is it generating any significant amount of CPU load? We're not
> talking about a high-bandwidth interface here.

For some customers _any_ amount is significant, especially
on large clustered systems where the amount is multiplied
by tens or hundreds of thousands of nodes.

You many not think wasting their cpu cycles is important, but they do.


-- 
Russ Anderson,  Kernel and Performance Software Team Manager
SGI - Silicon Graphics Inc          rja@sgi.com