diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ddb0575c6b4a..0756f046b644 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8918,125 +8918,6 @@ void *__init alloc_large_system_hash(const char *tablename, return table; } -/* - * This function checks whether pageblock includes unmovable pages or not. - * - * PageLRU check without isolation or lru_lock could race so that - * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable - * check without lock_page also may miss some movable non-lru pages at - * race condition. So you can't expect this function should be exact. - * - * Returns a page without holding a reference. If the caller wants to - * dereference that page (e.g., dumping), it has to make sure that it - * cannot get removed (e.g., via memory unplug) concurrently. - * - */ -struct page *has_unmovable_pages(struct zone *zone, struct page *page, - int migratetype, int flags) -{ - unsigned long iter = 0; - unsigned long pfn = page_to_pfn(page); - unsigned long offset = pfn % pageblock_nr_pages; - - if (is_migrate_cma_page(page)) { - /* - * CMA allocations (alloc_contig_range) really need to mark - * isolate CMA pageblocks even when they are not movable in fact - * so consider them movable here. - */ - if (is_migrate_cma(migratetype)) - return NULL; - - return page; - } - - for (; iter < pageblock_nr_pages - offset; iter++) { - page = pfn_to_page(pfn + iter); - - /* - * Both, bootmem allocations and memory holes are marked - * PG_reserved and are unmovable. We can even have unmovable - * allocations inside ZONE_MOVABLE, for example when - * specifying "movablecore". - */ - if (PageReserved(page)) - return page; - - /* - * If the zone is movable and we have ruled out all reserved - * pages then it should be reasonably safe to assume the rest - * is movable. - */ - if (zone_idx(zone) == ZONE_MOVABLE) - continue; - - /* - * Hugepages are not in LRU lists, but they're movable. - * THPs are on the LRU, but need to be counted as #small pages. - * We need not scan over tail pages because we don't - * handle each tail page individually in migration. - */ - if (PageHuge(page) || PageTransCompound(page)) { - struct page *head = compound_head(page); - unsigned int skip_pages; - - if (PageHuge(page)) { - if (!hugepage_migration_supported(page_hstate(head))) - return page; - } else if (!PageLRU(head) && !__PageMovable(head)) { - return page; - } - - skip_pages = compound_nr(head) - (page - head); - iter += skip_pages - 1; - continue; - } - - /* - * We can't use page_count without pin a page - * because another CPU can free compound page. - * This check already skips compound tails of THP - * because their page->_refcount is zero at all time. - */ - if (!page_ref_count(page)) { - if (PageBuddy(page)) - iter += (1 << buddy_order(page)) - 1; - continue; - } - - /* - * The HWPoisoned page may be not in buddy system, and - * page_count() is not 0. - */ - if ((flags & MEMORY_OFFLINE) && PageHWPoison(page)) - continue; - - /* - * We treat all PageOffline() pages as movable when offlining - * to give drivers a chance to decrement their reference count - * in MEM_GOING_OFFLINE in order to indicate that these pages - * can be offlined as there are no direct references anymore. - * For actually unmovable PageOffline() where the driver does - * not support this, we will fail later when trying to actually - * move these pages that still have a reference count > 0. - * (false negatives in this function only) - */ - if ((flags & MEMORY_OFFLINE) && PageOffline(page)) - continue; - - if (__PageMovable(page) || PageLRU(page)) - continue; - - /* - * If there are RECLAIMABLE pages, we need to check - * it. But now, memory offline itself doesn't call - * shrink_node_slabs() and it still to be fixed. - */ - return page; - } - return NULL; -} - #ifdef CONFIG_CONTIG_ALLOC static unsigned long pfn_max_align_down(unsigned long pfn) { |