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 <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: David Hildenbrand <david@xxxxxxxxxx> > Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> > Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxx> > Cc: Oscar Salvador <osalvador@xxxxxxx> > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > --- > 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
