Re: [PATCH] arch_numa: Restore nid checks before registering a memblock with a node

[Marc Zyngier <maz@kernel.org>]

Hi Mike,

On Thu, 28 Nov 2024 07:03:33 +0000,
Mike Rapoport <rppt@kernel.org> wrote:
> 
> Hi Marc,
> 
> > diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c
> > index e187016764265..5457248eb0811 100644
> > --- a/drivers/base/arch_numa.c
> > +++ b/drivers/base/arch_numa.c
> > @@ -207,7 +207,21 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
> >  static int __init numa_register_nodes(void)
> >  {
> >  	int nid;
> > -
> > +	struct memblock_region *mblk;
> > +
> > +	/* Check that valid nid is set to memblks */
> > +	for_each_mem_region(mblk) {
> > +		int mblk_nid = memblock_get_region_node(mblk);
> > +		phys_addr_t start = mblk->base;
> > +		phys_addr_t end = mblk->base + mblk->size - 1;
> > +
> > +		if (mblk_nid == NUMA_NO_NODE || mblk_nid >= MAX_NUMNODES) {
> > +			pr_warn("Warning: invalid memblk node %d [mem %pap-%pap]\n",
> > +				mblk_nid, &start, &end);
> > +			return -EINVAL;
> > +		}
> 
> We have memblock_validate_numa_coverage() that checks that amount of memory
> with unset node id is less than a threshold. The loop here can be replaced
> with something like
> 
> 	if (!memblock_validate_numa_coverage(0))
> 		return -EINVAL;

Unfortunately, that doesn't seem to result in something that works
(relevant extract only):

[    0.000000] NUMA: no nodes coverage for 9MB of 65516MB RAM
[    0.000000] NUMA: Faking a node at [mem 0x0000000000500000-0x0000000fff0fffff]
[    0.000000] NUMA: no nodes coverage for 0MB of 65516MB RAM
[    0.000000] Unable to handle kernel paging request at virtual address 0000000000001d40

Any idea?

	M.

-- 
Without deviation from the norm, progress is not possible.