On 18.07.19 16:22, David Hildenbrand wrote:
> We don't allow to offline memory block devices that belong to multiple
> numa nodes. Therefore, such devices can never get removed. It is
> sufficient to process a single node when removing the memory block.
>
> Remember for each memory block if it belongs to no, a single, or mixed
> nodes, so we can use that information to skip unregistering or print a
> warning (essentially a safety net to catch BUGs).
>
> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <raf...@kernel.org>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: David Hildenbrand <da...@redhat.com>
> Cc: Stephen Rothwell <s...@canb.auug.org.au>
> Cc: Pavel Tatashin <pasha.tatas...@soleen.com>
> Cc: Michal Hocko <mho...@suse.com>
> Cc: Oscar Salvador <osalva...@suse.de>
> Signed-off-by: David Hildenbrand <da...@redhat.com>
> ---
> drivers/base/memory.c | 1 +
> drivers/base/node.c | 40 ++++++++++++++++------------------------
> include/linux/memory.h | 4 +++-
> 3 files changed, 20 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 20c39d1bcef8..154d5d4a0779 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -674,6 +674,7 @@ static int init_memory_block(struct memory_block **memory,
> mem->state = state;
> start_pfn = section_nr_to_pfn(mem->start_section_nr);
> mem->phys_device = arch_get_memory_phys_device(start_pfn);
> + mem->nid = NUMA_NO_NODE;
>
> ret = register_memory(mem);
>
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index 75b7e6f6535b..29d27b8d5fda 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -759,8 +759,6 @@ static int register_mem_sect_under_node(struct
> memory_block *mem_blk,
> int ret, nid = *(int *)arg;
> unsigned long pfn, sect_start_pfn, sect_end_pfn;
>
> - mem_blk->nid = nid;
> -
> sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
> sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
> sect_end_pfn += PAGES_PER_SECTION - 1;
> @@ -789,6 +787,13 @@ static int register_mem_sect_under_node(struct
> memory_block *mem_blk,
> if (page_nid != nid)
> continue;
> }
> +
> + /* this memory block spans this node */
> + if (mem_blk->nid == NUMA_NO_NODE)
> + mem_blk->nid = nid;
> + else
> + mem_blk->nid = NUMA_NO_NODE - 1;
> +
Although I am not sure if it can happen, I think it is better to have
if (mem_blk->nid == NUMA_NO_NODE)
mem_blk->nid = nid;
else if (mem_blk->nid != nid)
mem_blk->nid = NUMA_NO_NODE - 1;
--
Thanks,
David / dhildenb
