RE: [PATCH RFC] mm: numa_clear_kernel_node_hotplug: Add NUMA_NO_NODE check for node id

[nobuhiro1.iwamatsu]

Hi Mike,

> -----Original Message-----
> From: Mike Rapoport <rppt@xxxxxxxxxx>
> Sent: Wednesday, October 16, 2024 5:12 PM
> To: iwamatsu nobuhiro(岩松 信洋 ○ＤＩＴＣ□ＤＩＴ○ＯＳＴ)
> <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>
> Cc: linux-mm@xxxxxxxxx; Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>;
> linux-kernel@xxxxxxxxxxxxxxx; ishikawa yuji(石川 悠司 ○ＲＤＣ□ＡＩＴＣ○
> ＥＡ開) <yuji2.ishikawa@xxxxxxxxxxxxx>
> Subject: Re: [PATCH RFC] mm: numa_clear_kernel_node_hotplug: Add
> NUMA_NO_NODE check for node id
> 
> On Wed, Oct 16, 2024 at 02:37:10PM +0900, Nobuhiro Iwamatsu wrote:
> > The acquired memory blocks for reserved may include blocks outside of
> > memory management. In this case, the nid variable is set to
> > NUMA_NO_NODE (-1), so an error occurs in node_set().
> > This adds a check to numa_clear_kernel_node_hotplug that skips
> > node_set when nid is set to NUMA_NO_NODE.
> >
> > Fixes: 87482708210f ("mm: introduce numa_memblks")
> > Suggested-by: Yuji Ishikawa <yuji2.ishikawa@xxxxxxxxxxxxx>
> > Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>
> > Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> > ---
> >  mm/numa_memblks.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c index
> > be52b93a9c58..b982f9260872 100644
> > --- a/mm/numa_memblks.c
> > +++ b/mm/numa_memblks.c
> > @@ -349,7 +349,7 @@ static void __init
> numa_clear_kernel_node_hotplug(void)
> >  	for_each_reserved_mem_region(mb_region) {
> >  		int nid = memblock_get_region_node(mb_region);
> >
> > -		if (nid != MAX_NUMNODES)
> > +		if (nid != NUMA_NO_NODE && nid != MAX_NUMNODES)
> 
> We have numa_valid_node() check for this, please use that.

Thanks. I will send v2 with it.

> Otherwise
> 
> Reviewed-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> 
> >  			node_set(nid, reserved_nodemask);
> >  	}
> >
> > --
> > 2.45.2
> >
> >
> 
> --
> Sincerely yours,
> Mike.

Best regards,
  Nobuhiro