diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index df291f2e509d..3f8a109d5129 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1773,7 +1773,7 @@ found: static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; - struct page *page, *head; + struct page *page; LIST_HEAD(source); static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); @@ -1786,14 +1786,20 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) continue; page = pfn_to_page(pfn); folio = page_folio(page); - head = &folio->page; - if (PageHuge(page)) { - pfn = page_to_pfn(head) + compound_nr(head) - 1; - isolate_hugetlb(folio, &source); - continue; - } else if (PageTransHuge(page)) - pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; + /* + * No reference or lock is held on the folio, so it might + * be modified concurrently (e.g. split). As such, + * folio_nr_pages() may read garbage. This is fine as the outer + * loop will revisit the split folio later. + */ + if (folio_test_large(folio)) { + pfn = folio_pfn(folio) + folio_nr_pages(folio) - 1; + if (folio_test_hugetlb(folio)) { + isolate_hugetlb(folio, &source); + continue; + } + } /* * HWPoison pages have elevated reference counts so the migration would |