[v1] target/ppc: Support adding memory to initially memory-less NUMA nodes

[Qemu-devel] [PATCH for 2.13 0/2] target/ppc: Support adding memory to initially memory-less NUMA nodes

Posted by Serhii Popovych 6 years ago

Now PowerPC Linux kernel supports hot-add to NUMA nodes not populated
initially with memory we can enable such support in qemu. This requires
two changes:

  o Add device tree property "ibm,max-associativity-domains" to let
    guest kernel chance to find max possible NUMA node

  o Revert  commit b556854bd852 ("spapr: Don't allow memory hotplug to
    memory less nodes") to remove check for hot-add to memory-less node.

See description messges for individual changes for more details.

Serhii Popovych (2):
  Revert "spapr: Don't allow memory hotplug to memory less nodes"
  spapr: Add ibm,max-associativity-domains property

 hw/ppc/spapr.c | 33 +++++++++++----------------------
 1 file changed, 11 insertions(+), 22 deletions(-)

-- 
1.8.3.1

Re: [Qemu-devel] [Qemu-ppc] [PATCH for 2.13 0/2] target/ppc: Support adding memory to initially memory-less NUMA nodes

Posted by Greg Kurz 6 years ago

On Thu,  5 Apr 2018 10:35:21 -0400
Serhii Popovych <spopovyc@redhat.com> wrote:

> Now PowerPC Linux kernel supports hot-add to NUMA nodes not populated
> initially with memory we can enable such support in qemu. This requires
> two changes:
> 
>   o Add device tree property "ibm,max-associativity-domains" to let
>     guest kernel chance to find max possible NUMA node
> 
>   o Revert  commit b556854bd852 ("spapr: Don't allow memory hotplug to
>     memory less nodes") to remove check for hot-add to memory-less node.
> 

But the series do the changes in the opposite order... 

IIUC correctly a recent kernel will mis-behave as before linux commit
a346137e9142 if the property is not present... ie, patch 2 should come
first.

> See description messges for individual changes for more details.
> 
> Serhii Popovych (2):
>   Revert "spapr: Don't allow memory hotplug to memory less nodes"
>   spapr: Add ibm,max-associativity-domains property
> 
>  hw/ppc/spapr.c | 33 +++++++++++----------------------
>  1 file changed, 11 insertions(+), 22 deletions(-)
>

Re: [Qemu-devel] [Qemu-ppc] [PATCH for 2.13 0/2] target/ppc: Support adding memory to initially memory-less NUMA nodes

Posted by David Gibson 6 years ago

On Fri, Apr 06, 2018 at 10:21:36AM +0200, Greg Kurz wrote:
> On Thu,  5 Apr 2018 10:35:21 -0400
> Serhii Popovych <spopovyc@redhat.com> wrote:
> 
> > Now PowerPC Linux kernel supports hot-add to NUMA nodes not populated
> > initially with memory we can enable such support in qemu. This requires
> > two changes:
> > 
> >   o Add device tree property "ibm,max-associativity-domains" to let
> >     guest kernel chance to find max possible NUMA node
> > 
> >   o Revert  commit b556854bd852 ("spapr: Don't allow memory hotplug to
> >     memory less nodes") to remove check for hot-add to memory-less node.
> > 
> 
> But the series do the changes in the opposite order... 

Right, the patches should go in the reverse order to avoid breaking
bisections.

> IIUC correctly a recent kernel will mis-behave as before linux commit
> a346137e9142 if the property is not present... ie, patch 2 should come
> first.
> 
> > See description messges for individual changes for more details.
> > 
> > Serhii Popovych (2):
> >   Revert "spapr: Don't allow memory hotplug to memory less nodes"
> >   spapr: Add ibm,max-associativity-domains property
> > 
> >  hw/ppc/spapr.c | 33 +++++++++++----------------------
> >  1 file changed, 11 insertions(+), 22 deletions(-)
> > 
> 

-- 
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