Re: alloc_pages_node(... GFP_KERNEL | GFP_THISNODE ...) fails

[Andi Kleen <andi@firstfloor.org>]

On Fri, May 29, 2009 at 06:18:44PM +0200, Max Laier wrote:
> 
> Am Fr, 29.05.2009, 17:01, schrieb Andi Kleen:
> > On Fri, May 29, 2009 at 09:54:06AM -0400, Christoph Lameter wrote:
> >> On Fri, 29 May 2009, Max Laier wrote:
> >>
> >> > Same result.  "numa_hit" in node 7 increases, while "nr_free_pages"
> >> stays
> >> > the same.  Anything else you'd want me to watch out for?
> >>
> >> That looks like a bug in fake numa.
> >
> > I also got some reports of fake numa being a bit broken recently.
> 
> That might have been me too - I sent you a private mail earlier this week.

No that was from someone else. Also I don't have an email from you in 
my mailbox, so I didn't see it.

> I guess the question is, what is special about my allocation in KVM as

Define "in KVM"?

Inside the guest? 

> opposed to the allocation in the test module (that works as expected). 

I thought you complained that the test module didn't increase the numastat
counters as expected?

> The userland test tools from the numactl package also work as expected in
> membind mode.
> 
> Also, I have been reading the fake numa setup back and forth and I really

To be honest I don't understand it anymore either since it got so much
new stuff a couple of years back. All I can say it worked when
I wrote it originally and set up the nodes in exactly the same
way as the native NUMA setup on x86-64.


> I'll take another look at the fake numa setup later today.  Any chance
> somebody could give the KVM thing a try on real numa hardware?  Though
> there are probably not that many systems that have real numa and kvm
> support ... dual socket Gainestown setup anyone?

I don't understand. There are lots of KVM capable NUMA systems.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.