On Wed, Nov 09, 2016 at 04:55:49PM +0100, Gerald Schaefer wrote: > > index 9fdfc24..5dbfd62 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -1095,6 +1095,9 @@ static struct page *alloc_gigantic_page(int nid, unsigned int order) > > unsigned long ret, pfn, flags; > > struct zone *z; > > > > + if (nid == NUMA_NO_NODE) > > + nid = numa_mem_id(); > > + > > Now counter.sh works (on s390) w/o the lockdep warning. However, it looks Good news to me :) We have found the root cause of the s390 issue. > like this change will now result in inconsistent behavior compared to the > normal sized hugepages, regarding surplus page allocation. Setting nid to > numa_mem_id() means that only the node of the current CPU will be considered > for allocating a gigantic page, as opposed to just "preferring" the current > node in the normal size case (__hugetlb_alloc_buddy_huge_page() -> > alloc_pages_node()) with a fallback to using other nodes. Yes. > > I am not really familiar with NUMA, and I might be wrong here, but if > this is true then gigantic pages, which may be hard allocate at runtime > in general, will be even harder to find (as surplus pages) because you > only look on the current node. Okay, I will try to fix this in the next version. > > I honestly do not understand why alloc_gigantic_page() needs a nid > parameter at all, since it looks like it will only be called from > alloc_fresh_gigantic_page_node(), which in turn is only called > from alloc_fresh_gigantic_page() in a "for_each_node" loop (at least > before your patch). > > Now it could be an option to also use alloc_fresh_gigantic_page() > in your patch, instead of directly calling alloc_gigantic_page(), Yes, a good suggestion. But I need to do some change to the alloc_fresh_gigantic_page(). Thanks Huang Shijie -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>