Messages in this thread | | | Subject | Re: [PATCH v3 0/5] mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by default for NUMA | From | Hoan Tran <> | Date | Thu, 2 Apr 2020 21:46:05 -0700 |
| |
Hi All,
On 3/31/20 7:31 AM, Baoquan He wrote: > On 03/31/20 at 04:21pm, Michal Hocko wrote: >> On Tue 31-03-20 22:03:32, Baoquan He wrote: >>> Hi Michal, >>> >>> On 03/31/20 at 10:55am, Michal Hocko wrote: >>>> On Tue 31-03-20 11:14:23, Mike Rapoport wrote: >>>>> Maybe I mis-read the code, but I don't see how this could happen. In the >>>>> HAVE_MEMBLOCK_NODE_MAP=y case, free_area_init_node() calls >>>>> calculate_node_totalpages() that ensures that node->node_zones are entirely >>>>> within the node because this is checked in zone_spanned_pages_in_node(). >>>> >>>> zone_spanned_pages_in_node does chech the zone boundaries are within the >>>> node boundaries. But that doesn't really tell anything about other >>>> potential zones interleaving with the physical memory range. >>>> zone->spanned_pages simply gives the physical range for the zone >>>> including holes. Interleaving nodes are essentially a hole >>>> (__absent_pages_in_range is going to skip those). >>>> >>>> That means that when free_area_init_core simply goes over the whole >>>> physical zone range including holes and that is why we need to check >>>> both for physical and logical holes (aka other nodes). >>>> >>>> The life would be so much easier if the whole thing would simply iterate >>>> over memblocks... >>> >>> The memblock iterating sounds a great idea. I tried with putting the >>> memblock iterating in the upper layer, memmap_init(), which is used for >>> boot mem only anyway. Do you think it's doable and OK? It yes, I can >>> work out a formal patch to make this simpler as you said. The draft code >>> is as below. Like this it uses the existing code and involves little change. >> >> Doing this would be a step in the right direction! I haven't checked the >> code very closely though. The below sounds way too simple to be truth I >> am afraid. First for_each_mem_pfn_range is available only for >> CONFIG_HAVE_MEMBLOCK_NODE_MAP (which is one of the reasons why I keep >> saying that I really hate that being conditional). Also I haven't really >> checked the deferred initialization path - I have a very vague >> recollection that it has been converted to the memblock api but I have >> happilly dropped all that memory. > > Thanks for your quick response and pointing out the rest suspect aspects, > I will investigate what you mentioned, see if they impact.
I would like to check if we still move on with my patch to remove CONFIG_NODES_SPAN_OTHER_NODES and have another patch on top it?
Thanks Hoan
> >> >>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >>> index 138a56c0f48f..558d421f294b 100644 >>> --- a/mm/page_alloc.c >>> +++ b/mm/page_alloc.c >>> @@ -6007,14 +6007,6 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, >>> * function. They do not exist on hotplugged memory. >>> */ >>> if (context == MEMMAP_EARLY) { >>> - if (!early_pfn_valid(pfn)) { >>> - pfn = next_pfn(pfn); >>> - continue; >>> - } >>> - if (!early_pfn_in_nid(pfn, nid)) { >>> - pfn++; >>> - continue; >>> - } >>> if (overlap_memmap_init(zone, &pfn)) >>> continue; >>> if (defer_init(nid, pfn, end_pfn)) >>> @@ -6130,9 +6122,17 @@ static void __meminit zone_init_free_lists(struct zone *zone) >>> } >>> >>> void __meminit __weak memmap_init(unsigned long size, int nid, >>> - unsigned long zone, unsigned long start_pfn) >>> + unsigned long zone, unsigned long range_start_pfn) >>> { >>> - memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY, NULL); >>> + unsigned long start_pfn, end_pfn; >>> + unsigned long range_end_pfn = range_start_pfn + size; >>> + int i; >>> + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { >>> + start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); >>> + end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); >>> + if (end_pfn > start_pfn) >>> + memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY, NULL); >>> + } >>> } >>> >>> static int zone_batchsize(struct zone *zone) >> >> -- >> Michal Hocko >> SUSE Labs >> >
| |