Re: [PATCH] arm64: Kconfig: Enable NODES_SPAN_OTHER_NODES config for NUMA

[Catalin Marinas]

On Thu, Feb 06, 2020 at 12:01:19PM -0800, Hoan Tran wrote:
> Hi Will,
> 
> On 2/6/20 2:23 AM, Will Deacon wrote:
> > On Mon, Feb 03, 2020 at 11:55:14AM -0800, Hoan Tran wrote:
> > > Some NUMA nodes have memory ranges that span other nodes.
> > > Even though a pfn is valid and between a node's start and end pfns,
> > > it may not reside on that node.
> > > 
> > > This patch enables NODES_SPAN_OTHER_NODES config for NUMA to support
> > > this type of NUMA layout.
> > > 
> > > Signed-off-by: Hoan Tran <Hoan@xxxxxxxxxxxxxxxxxxxxxx>
> > > ---
> > >   arch/arm64/Kconfig | 7 +++++++
> > >   1 file changed, 7 insertions(+)
> > > 
> > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > > index e688dfa..939d28f 100644
> > > --- a/arch/arm64/Kconfig
> > > +++ b/arch/arm64/Kconfig
> > > @@ -959,6 +959,13 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK
> > >   config HOLES_IN_ZONE
> > >   	def_bool y
> > > +# Some NUMA nodes have memory ranges that span other nodes.
> > > +# Even though a pfn is valid and between a node's start and end pfns,
> > > +# it may not reside on that node.
> > > +config NODES_SPAN_OTHER_NODES
> > > +	def_bool y
> > > +	depends on ACPI_NUMA
> > > +
> > 
> > I thought we agreed to do this in the core code?
> > 
> > https://lore.kernel.org/lkml/1562887528-5896-1-git-send-email-Hoan@xxxxxxxxxxxxxxxxxxxxxx
> 
> Yes, but it looks like Thomas didn't agree to apply this patch into
> x86.
> 
> https://lore.kernel.org/lkml/alpine.DEB.2.21.1907152042110.1767@xxxxxxxxxxxxxxxxxxxxxxx/

Was it a clear statement that such change will not make it to x86 or a
request for improving the patch or the description? I'd suggest you
update the x86 patch comment to include the rationale as per your reply
to Thomas and post a new version of the generic series. If Thomas (or
the mm folk) reject it again, we'll revisit the arm64-specific thread.

-- 
Catalin