diff --git a/mm/page_owner.c b/mm/page_owner.c index 85eec7ea6735..9ab4a9b5bc09 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -10,6 +10,8 @@ static bool page_owner_disabled = true; bool page_owner_inited __read_mostly; +static void init_early_allocated_pages(void); + static int early_page_owner_param(char *buf) { if (!buf) @@ -36,6 +38,7 @@ static void init_page_owner(void) return; page_owner_inited = true; + init_early_allocated_pages(); } struct page_ext_operations page_owner_ops = { @@ -184,8 +187,8 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) page_ext = lookup_page_ext(page); /* - * Pages allocated before initialization of page_owner are - * non-buddy and have no page_owner info. + * Some pages could be missed by concurrent allocation or free, + * because we don't hold the zone lock. */ if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) continue; @@ -199,6 +202,92 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) return 0; } +static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) +{ + struct page *page; + struct page_ext *page_ext; + unsigned long pfn = zone->zone_start_pfn, block_end_pfn; + unsigned long end_pfn = pfn + zone->spanned_pages; + unsigned long count = 0; + + /* Scan block by block. First and last block may be incomplete */ + pfn = zone->zone_start_pfn; + + /* + * Walk the zone in pageblock_nr_pages steps. If a page block spans + * a zone boundary, it will be double counted between zones. This does + * not matter as the mixed block count will still be correct + */ + for (; pfn < end_pfn; ) { + if (!pfn_valid(pfn)) { + pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); + continue; + } + + block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); + block_end_pfn = min(block_end_pfn, end_pfn); + + page = pfn_to_page(pfn); + + for (; pfn < block_end_pfn; pfn++) { + if (!pfn_valid_within(pfn)) + continue; + + page = pfn_to_page(pfn); + + /* + * We are safe to check buddy flag and order, because + * this is init stage and only single thread runs. + */ + if (PageBuddy(page)) { + pfn += (1UL << page_order(page)) - 1; + continue; + } + + if (PageReserved(page)) + continue; + + page_ext = lookup_page_ext(page); + + /* Maybe overraping zone */ + if (test_bit(PAGE_EXT_OWNER, &page_ext->flags)) + continue; + + /* Found early allocated page */ + set_page_owner(page, 0, 0); + count++; + } + } + + pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n", + pgdat->node_id, zone->name, count); +} + +static void init_zones_in_node(pg_data_t *pgdat) +{ + struct zone *zone; + struct zone *node_zones = pgdat->node_zones; + unsigned long flags; + + for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { + if (!populated_zone(zone)) + continue; + + spin_lock_irqsave(&zone->lock, flags); + init_pages_in_zone(pgdat, zone); + spin_unlock_irqrestore(&zone->lock, flags); + } +} + +static void init_early_allocated_pages(void) +{ + pg_data_t *pgdat; + + drain_all_pages(NULL); + for_each_online_pgdat(pgdat) + init_zones_in_node(pgdat); +} + static const struct file_operations proc_page_owner_operations = { .read = read_page_owner, };