On 05/13/2017 03:05 AM, Andrew Morton wrote: > On Wed, 26 Apr 2017 09:27:31 +0530 Anshuman Khandual > <[email protected]> wrote: > >> Though migrating gigantic HugeTLB pages does not sound much like real >> world use case, they can be affected by memory errors. Hence migration >> at the PGD level HugeTLB pages should be supported just to enable soft >> and hard offline use cases. >> >> While allocating the new gigantic HugeTLB page, it should not matter >> whether new page comes from the same node or not. There would be very >> few gigantic pages on the system afterall, we should not be bothered >> about node locality when trying to save a big page from crashing. >> >> This introduces a new HugeTLB allocator called alloc_huge_page_nonid() >> which will scan over all online nodes on the system and allocate a >> single HugeTLB page. >> >> ... >> >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -1669,6 +1669,23 @@ struct page *__alloc_buddy_huge_page_with_mpol(struct >> hstate *h, >> return __alloc_buddy_huge_page(h, vma, addr, NUMA_NO_NODE); >> } >> >> +struct page *alloc_huge_page_nonid(struct hstate *h) >> +{ >> + struct page *page = NULL; >> + int nid = 0; >> + >> + spin_lock(&hugetlb_lock); >> + if (h->free_huge_pages - h->resv_huge_pages > 0) { >> + for_each_online_node(nid) { >> + page = dequeue_huge_page_node(h, nid); >> + if (page) >> + break; >> + } >> + } >> + spin_unlock(&hugetlb_lock); >> + return page; >> +} >> + >> /* >> * This allocation function is useful in the context where vma is >> irrelevant. >> * E.g. soft-offlining uses this function because it only cares physical >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index fe64d7729a8e..d4f5710cf3f7 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -1481,11 +1481,15 @@ EXPORT_SYMBOL(unpoison_memory); >> static struct page *new_page(struct page *p, unsigned long private, int **x) >> { >> int nid = page_to_nid(p); >> - if (PageHuge(p)) >> + if (PageHuge(p)) { >> + if (hstate_is_gigantic(page_hstate(compound_head(p)))) >> + return >> alloc_huge_page_nonid(page_hstate(compound_head(p))); >> + >> return alloc_huge_page_node(page_hstate(compound_head(p)), >> nid); >> - else >> + } else { >> return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0); >> + } >> } > > Rather than adding alloc_huge_page_nonid(), would it be neater to teach > alloc_huge_page_node() (actually dequeue_huge_page_node()) to understand > nid==NUMA_NO_NODE?
Sure, will change dequeue_huge_page_node() to accommodate NUMA_NO_NODE and let soft offline call with NUMA_NO_NODE in case of gigantic huge pages.
