diff options
Diffstat (limited to 'mm/page_isolation.c')
| -rw-r--r-- | mm/page_isolation.c | 166 |
1 files changed, 149 insertions, 17 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 4ae42bb4089..d1473b2e948 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -5,8 +5,88 @@ #include <linux/mm.h> #include <linux/page-isolation.h> #include <linux/pageblock-flags.h> +#include <linux/memory.h> +#include <linux/hugetlb.h> #include "internal.h" +int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages) +{ + struct zone *zone; + unsigned long flags, pfn; + struct memory_isolate_notify arg; + int notifier_ret; + int ret = -EBUSY; + + zone = page_zone(page); + + spin_lock_irqsave(&zone->lock, flags); + + pfn = page_to_pfn(page); + arg.start_pfn = pfn; + arg.nr_pages = pageblock_nr_pages; + arg.pages_found = 0; + + /* + * It may be possible to isolate a pageblock even if the + * migratetype is not MIGRATE_MOVABLE. The memory isolation + * notifier chain is used by balloon drivers to return the + * number of pages in a range that are held by the balloon + * driver to shrink memory. If all the pages are accounted for + * by balloons, are free, or on the LRU, isolation can continue. + * Later, for example, when memory hotplug notifier runs, these + * pages reported as "can be isolated" should be isolated(freed) + * by the balloon driver through the memory notifier chain. + */ + notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg); + notifier_ret = notifier_to_errno(notifier_ret); + if (notifier_ret) + goto out; + /* + * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself. + * We just check MOVABLE pages. + */ + if (!has_unmovable_pages(zone, page, arg.pages_found, + skip_hwpoisoned_pages)) + ret = 0; + + /* + * immobile means "not-on-lru" paes. If immobile is larger than + * removable-by-driver pages reported by notifier, we'll fail. + */ + +out: + if (!ret) { + unsigned long nr_pages; + int migratetype = get_pageblock_migratetype(page); + + set_pageblock_migratetype(page, MIGRATE_ISOLATE); + nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE); + + __mod_zone_freepage_state(zone, -nr_pages, migratetype); + } + + spin_unlock_irqrestore(&zone->lock, flags); + if (!ret) + drain_all_pages(); + return ret; +} + +void unset_migratetype_isolate(struct page *page, unsigned migratetype) +{ + struct zone *zone; + unsigned long flags, nr_pages; + + zone = page_zone(page); + spin_lock_irqsave(&zone->lock, flags); + if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) + goto out; + nr_pages = move_freepages_block(zone, page, migratetype); + __mod_zone_freepage_state(zone, nr_pages, migratetype); + set_pageblock_migratetype(page, migratetype); +out: + spin_unlock_irqrestore(&zone->lock, flags); +} + static inline struct page * __first_valid_page(unsigned long pfn, unsigned long nr_pages) { @@ -24,6 +104,7 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages) * to be MIGRATE_ISOLATE. * @start_pfn: The lower PFN of the range to be isolated. * @end_pfn: The upper PFN of the range to be isolated. + * @migratetype: migrate type to set in error recovery. * * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in * the range will never be allocated. Any free pages and pages freed in the @@ -32,8 +113,8 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages) * start_pfn/end_pfn must be aligned to pageblock_order. * Returns 0 on success and -EBUSY if any part of range cannot be isolated. */ -int -start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn) +int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, + unsigned migratetype, bool skip_hwpoisoned_pages) { unsigned long pfn; unsigned long undo_pfn; @@ -46,7 +127,8 @@ start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn) pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); - if (page && set_migratetype_isolate(page)) { + if (page && + set_migratetype_isolate(page, skip_hwpoisoned_pages)) { undo_pfn = pfn; goto undo; } @@ -56,7 +138,7 @@ undo: for (pfn = start_pfn; pfn < undo_pfn; pfn += pageblock_nr_pages) - unset_migratetype_isolate(pfn_to_page(pfn)); + unset_migratetype_isolate(pfn_to_page(pfn), migratetype); return -EBUSY; } @@ -64,8 +146,8 @@ undo: /* * Make isolated pages available again. */ -int -undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn) +int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, + unsigned migratetype) { unsigned long pfn; struct page *page; @@ -77,7 +159,7 @@ undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn) page = __first_valid_page(pfn, pageblock_nr_pages); if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE) continue; - unset_migratetype_isolate(page); + unset_migratetype_isolate(page, migratetype); } return 0; } @@ -86,10 +168,11 @@ undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn) * all pages in [start_pfn...end_pfn) must be in the same zone. * zone->lock must be held before call this. * - * Returns 1 if all pages in the range is isolated. + * Returns 1 if all pages in the range are isolated. */ static int -__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn) +__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn, + bool skip_hwpoisoned_pages) { struct page *page; @@ -99,11 +182,34 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn) continue; } page = pfn_to_page(pfn); - if (PageBuddy(page)) + if (PageBuddy(page)) { + /* + * If race between isolatation and allocation happens, + * some free pages could be in MIGRATE_MOVABLE list + * although pageblock's migratation type of the page + * is MIGRATE_ISOLATE. Catch it and move the page into + * MIGRATE_ISOLATE list. + */ + if (get_freepage_migratetype(page) != MIGRATE_ISOLATE) { + struct page *end_page; + + end_page = page + (1 << page_order(page)) - 1; + move_freepages(page_zone(page), page, end_page, + MIGRATE_ISOLATE); + } pfn += 1 << page_order(page); + } else if (page_count(page) == 0 && - page_private(page) == MIGRATE_ISOLATE) + get_freepage_migratetype(page) == MIGRATE_ISOLATE) pfn += 1; + else if (skip_hwpoisoned_pages && PageHWPoison(page)) { + /* + * The HWPoisoned page may be not in buddy + * system, and page_count() is not 0. + */ + pfn++; + continue; + } else break; } @@ -112,7 +218,8 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn) return 1; } -int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) +int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn, + bool skip_hwpoisoned_pages) { unsigned long pfn, flags; struct page *page; @@ -120,9 +227,9 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) int ret; /* - * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page - * is not aligned to pageblock_nr_pages. - * Then we just check pagetype fist. + * Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages + * are not aligned to pageblock_nr_pages. + * Then we just check migratetype first. */ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); @@ -132,10 +239,35 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) page = __first_valid_page(start_pfn, end_pfn - start_pfn); if ((pfn < end_pfn) || !page) return -EBUSY; - /* Check all pages are free or Marked as ISOLATED */ + /* Check all pages are free or marked as ISOLATED */ zone = page_zone(page); spin_lock_irqsave(&zone->lock, flags); - ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn); + ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn, + skip_hwpoisoned_pages); spin_unlock_irqrestore(&zone->lock, flags); return ret ? 0 : -EBUSY; } + +struct page *alloc_migrate_target(struct page *page, unsigned long private, + int **resultp) +{ + gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE; + + /* + * TODO: allocate a destination hugepage from a nearest neighbor node, + * accordance with memory policy of the user process if possible. For + * now as a simple work-around, we use the next node for destination. + */ + if (PageHuge(page)) { + nodemask_t src = nodemask_of_node(page_to_nid(page)); + nodemask_t dst; + nodes_complement(dst, src); + return alloc_huge_page_node(page_hstate(compound_head(page)), + next_node(page_to_nid(page), dst)); + } + + if (PageHighMem(page)) + gfp_mask |= __GFP_HIGHMEM; + + return alloc_page(gfp_mask); +} |