Re: [PATCH 1/2] numa: Add simple generic NUMA emulation

[Mike Rapoport <rppt@kernel.org>]

Hi Tvrtko,

On Mon, Aug 12, 2024 at 05:35:31PM +0100, Tvrtko Ursulin wrote:
> 
> Hi Jonathan,
> 
> On 08/08/2024 17:27, Jonathan Cameron wrote:
> > On Thu, 8 Aug 2024 12:56:44 +0100
> > Tvrtko Ursulin <tvrtko.ursulin@igalia.com> wrote:
> > > 
> > > c)
> > > Strong nack for either a) or b) - so "do it in the firmware" comment.
> > > 
> > > Trying to understand your position so we can progress this.
> > 
> > See:
> > https://lore.kernel.org/all/20240807064110.1003856-20-rppt@kernel.org/
> > and rest of thread
> > https://lore.kernel.org/all/20240807064110.1003856-1-rppt@kernel.org/
> > [PATCH v4 00/26] mm: introduce numa_memblks
> > 
> > Much larger rework and unification set from Mike Rapoport
> > that happens to end up adding numa emulation as part of making
> > the x86 numa_memblk work for arm64 etc.
> > 
> > It's in mm-unstable now so getting some test coverage etc.
> > 
> > Sorry, I'd kind of assumed this also went to linux-mm so
> > the connection would have been made.
> 
> This is great - I did not see it since I don't read linux-mm regularly!
> 
> I gave Mike's implementation a spin on top of RPi 6.11 kernel and it mostly
> works fine.
> 
> Is the decision that this is going in pretty much set, that is, high level
> acks are there?

It's in mm-unstable now

https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/log/?h=mm-unstable

and I hope will go to Linus next merge window.
 
> One area to potentially improve is working around CMA areas when they are
> put by the firmware at a range which straddles two nodes. In my series,
> albeit not the one I yet posted, I have some code to fudge that so that CMA
> ends up wholly in one node and so CMA initialisation can succeed.
> 
> I can try and adapt that patch to this series and post as a RFC.
> 
> Then there are some odd things about NUMA, memory pressure and swap
> behaviour, but that is not specific to this series and not something I got
> to the bottom off just yet. Could be specific to my board and IO for
> instance.
> 
> Regards,
> 
> Tvrtko

-- 
Sincerely yours,
Mike.