Re: 2.6.23-mm1 breaks C-state support on Intel T7200 x86_64

[Andrew Morton <akpm@linux-foundation.org>]

> On Thu, 8 Nov 2007 12:03:52 -0800 Mark Gross <mgross@linux.intel.com> wrote:
> ...
> > >   call.
> > > 
> > > I shouldn't have to have a process open a /dev/file, write a number, and then
> > > stay around forever so the file doesn't close in order to get the same behavior
> > > I was getting by default before.  What needs to happen to get this to not
> > > be a behavior regression/change?
> > > 
> > 
> > That's a great report, thanks.  Over to you, Mark ;)
> > 
> > btw, I also have a note here that these patches caused Rafael to see an
> > smp_call_function() inside local_irq_save().  Did that get fixed?
> 
> Ah, I see the problem.  I think I posted a fix to this.  The problem is
> that what's in the mm1 tree has a parameter PM_QOS_IDLE that needed to
> be PM_QOS_CPU_DMA_LATENCY. 

That doesn't ring a bell.

> I'm not sure what's in the current MM tree at this point so I can't say
> its been fixed.  Is there an easy way from me to see what's currently in
> MM?  

Not terribly. 
ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/mm/broken-out-2007-11-06-02-32.tar.gz
is from two days ago.

> FWIW I think I fixed this when I fixed up Rafael's issue.  Would you
> like me to send out a re-fresh patch against 2.6.23-mm1?

sure.