diff options
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 304 |
1 files changed, 200 insertions, 104 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index c5ef7240cbcb..a5ad0b35ab8e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -46,9 +46,11 @@ #include <linux/delayacct.h> #include <linux/sysctl.h> #include <linux/oom.h> +#include <linux/pagevec.h> #include <linux/prefetch.h> #include <linux/printk.h> #include <linux/dax.h> +#include <linux/psi.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -86,6 +88,9 @@ struct scan_control { /* Can pages be swapped as part of reclaim? */ unsigned int may_swap:1; + /* e.g. boosted watermark reclaim leaves slabs alone */ + unsigned int may_shrinkslab:1; + /* * Cgroups are not reclaimed below their configured memory.low, * unless we threaten to OOM. If any cgroups are skipped due to @@ -369,7 +374,7 @@ unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone */ int prealloc_shrinker(struct shrinker *shrinker) { - size_t size = sizeof(*shrinker->nr_deferred); + unsigned int size = sizeof(*shrinker->nr_deferred); if (shrinker->flags & SHRINKER_NUMA_AWARE) size *= nr_node_ids; @@ -473,19 +478,18 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, nr = atomic_long_xchg(&shrinker->nr_deferred[nid], 0); total_scan = nr; - delta = freeable >> priority; - delta *= 4; - do_div(delta, shrinker->seeks); - - /* - * Make sure we apply some minimal pressure on default priority - * even on small cgroups. Stale objects are not only consuming memory - * by themselves, but can also hold a reference to a dying cgroup, - * preventing it from being reclaimed. A dying cgroup with all - * corresponding structures like per-cpu stats and kmem caches - * can be really big, so it may lead to a significant waste of memory. - */ - delta = max_t(unsigned long long, delta, min(freeable, batch_size)); + if (shrinker->seeks) { + delta = freeable >> priority; + delta *= 4; + do_div(delta, shrinker->seeks); + } else { + /* + * These objects don't require any IO to create. Trim + * them aggressively under memory pressure to keep + * them from causing refetches in the IO caches. + */ + delta = freeable / 2; + } total_scan += delta; if (total_scan < 0) { @@ -741,12 +745,12 @@ static inline int is_page_cache_freeable(struct page *page) { /* * A freeable page cache page is referenced only by the caller - * that isolated the page, the page cache radix tree and - * optional buffer heads at page->private. + * that isolated the page, the page cache and optional buffer + * heads at page->private. */ - int radix_pins = PageTransHuge(page) && PageSwapCache(page) ? + int page_cache_pins = PageTransHuge(page) && PageSwapCache(page) ? HPAGE_PMD_NR : 1; - return page_count(page) - page_has_private(page) == 1 + radix_pins; + return page_count(page) - page_has_private(page) == 1 + page_cache_pins; } static int may_write_to_inode(struct inode *inode, struct scan_control *sc) @@ -922,7 +926,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, if (PageSwapCache(page)) { swp_entry_t swap = { .val = page_private(page) }; mem_cgroup_swapout(page, swap); - __delete_from_swap_cache(page); + __delete_from_swap_cache(page, swap); xa_unlock_irqrestore(&mapping->i_pages, flags); put_swap_page(page, swap); } else { @@ -948,7 +952,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, */ if (reclaimed && page_is_file_cache(page) && !mapping_exiting(mapping) && !dax_mapping(mapping)) - shadow = workingset_eviction(mapping, page); + shadow = workingset_eviction(page); __delete_from_page_cache(page, shadow); xa_unlock_irqrestore(&mapping->i_pages, flags); @@ -1102,16 +1106,9 @@ static unsigned long shrink_page_list(struct list_head *page_list, { LIST_HEAD(ret_pages); LIST_HEAD(free_pages); - int pgactivate = 0; - unsigned nr_unqueued_dirty = 0; - unsigned nr_dirty = 0; - unsigned nr_congested = 0; unsigned nr_reclaimed = 0; - unsigned nr_writeback = 0; - unsigned nr_immediate = 0; - unsigned nr_ref_keep = 0; - unsigned nr_unmap_fail = 0; + memset(stat, 0, sizeof(*stat)); cond_resched(); while (!list_empty(page_list)) { @@ -1155,10 +1152,10 @@ static unsigned long shrink_page_list(struct list_head *page_list, */ page_check_dirty_writeback(page, &dirty, &writeback); if (dirty || writeback) - nr_dirty++; + stat->nr_dirty++; if (dirty && !writeback) - nr_unqueued_dirty++; + stat->nr_unqueued_dirty++; /* * Treat this page as congested if the underlying BDI is or if @@ -1170,7 +1167,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (((dirty || writeback) && mapping && inode_write_congested(mapping->host)) || (writeback && PageReclaim(page))) - nr_congested++; + stat->nr_congested++; /* * If a page at the tail of the LRU is under writeback, there @@ -1219,7 +1216,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (current_is_kswapd() && PageReclaim(page) && test_bit(PGDAT_WRITEBACK, &pgdat->flags)) { - nr_immediate++; + stat->nr_immediate++; goto activate_locked; /* Case 2 above */ @@ -1237,7 +1234,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, * and it's also appropriate in global reclaim. */ SetPageReclaim(page); - nr_writeback++; + stat->nr_writeback++; goto activate_locked; /* Case 3 above */ @@ -1257,7 +1254,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, case PAGEREF_ACTIVATE: goto activate_locked; case PAGEREF_KEEP: - nr_ref_keep++; + stat->nr_ref_keep++; goto keep_locked; case PAGEREF_RECLAIM: case PAGEREF_RECLAIM_CLEAN: @@ -1322,7 +1319,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (unlikely(PageTransHuge(page))) flags |= TTU_SPLIT_HUGE_PMD; if (!try_to_unmap(page, flags)) { - nr_unmap_fail++; + stat->nr_unmap_fail++; goto activate_locked; } } @@ -1446,14 +1443,8 @@ static unsigned long shrink_page_list(struct list_head *page_list, count_memcg_page_event(page, PGLAZYFREED); } else if (!mapping || !__remove_mapping(mapping, page, true)) goto keep_locked; - /* - * At this point, we have no other references and there is - * no way to pick any more up (removed from LRU, removed - * from pagecache). Can use non-atomic bitops now (and - * we obviously don't have to worry about waking up a process - * waiting on the page lock, because there are no references. - */ - __ClearPageLocked(page); + + unlock_page(page); free_it: nr_reclaimed++; @@ -1476,7 +1467,7 @@ activate_locked: VM_BUG_ON_PAGE(PageActive(page), page); if (!PageMlocked(page)) { SetPageActive(page); - pgactivate++; + stat->nr_activate++; count_memcg_page_event(page, PGACTIVATE); } keep_locked: @@ -1491,18 +1482,8 @@ keep: free_unref_page_list(&free_pages); list_splice(&ret_pages, page_list); - count_vm_events(PGACTIVATE, pgactivate); - - if (stat) { - stat->nr_dirty = nr_dirty; - stat->nr_congested = nr_congested; - stat->nr_unqueued_dirty = nr_unqueued_dirty; - stat->nr_writeback = nr_writeback; - stat->nr_immediate = nr_immediate; - stat->nr_activate = pgactivate; - stat->nr_ref_keep = nr_ref_keep; - stat->nr_unmap_fail = nr_unmap_fail; - } + count_vm_events(PGACTIVATE, stat->nr_activate); + return nr_reclaimed; } @@ -1514,6 +1495,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, .priority = DEF_PRIORITY, .may_unmap = 1, }; + struct reclaim_stat dummy_stat; unsigned long ret; struct page *page, *next; LIST_HEAD(clean_pages); @@ -1527,7 +1509,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, } ret = shrink_page_list(&clean_pages, zone->zone_pgdat, &sc, - TTU_IGNORE_ACCESS, NULL, true); + TTU_IGNORE_ACCESS, &dummy_stat, true); list_splice(&clean_pages, page_list); mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, -ret); return ret; @@ -1632,8 +1614,8 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec, } -/* - * zone_lru_lock is heavily contended. Some of the functions that +/** + * pgdat->lru_lock is heavily contended. Some of the functions that * shrink the lists perform better by taking out a batch of pages * and working on them outside the LRU lock. * @@ -1655,7 +1637,7 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec, static unsigned long isolate_lru_pages(unsigned long nr_to_scan, struct lruvec *lruvec, struct list_head *dst, unsigned long *nr_scanned, struct scan_control *sc, - isolate_mode_t mode, enum lru_list lru) + enum lru_list lru) { struct list_head *src = &lruvec->lists[lru]; unsigned long nr_taken = 0; @@ -1664,6 +1646,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, unsigned long skipped = 0; unsigned long scan, total_scan, nr_pages; LIST_HEAD(pages_skipped); + isolate_mode_t mode = (sc->may_unmap ? 0 : ISOLATE_UNMAPPED); scan = 0; for (total_scan = 0; @@ -1767,11 +1750,11 @@ int isolate_lru_page(struct page *page) WARN_RATELIMIT(PageTail(page), "trying to isolate tail page"); if (PageLRU(page)) { - struct zone *zone = page_zone(page); + pg_data_t *pgdat = page_pgdat(page); struct lruvec *lruvec; - spin_lock_irq(zone_lru_lock(zone)); - lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat); + spin_lock_irq(&pgdat->lru_lock); + lruvec = mem_cgroup_page_lruvec(page, pgdat); if (PageLRU(page)) { int lru = page_lru(page); get_page(page); @@ -1779,7 +1762,7 @@ int isolate_lru_page(struct page *page) del_page_from_lru_list(page, lruvec, lru); ret = 0; } - spin_unlock_irq(zone_lru_lock(zone)); + spin_unlock_irq(&pgdat->lru_lock); } return ret; } @@ -1901,8 +1884,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, unsigned long nr_scanned; unsigned long nr_reclaimed = 0; unsigned long nr_taken; - struct reclaim_stat stat = {}; - isolate_mode_t isolate_mode = 0; + struct reclaim_stat stat; int file = is_file_lru(lru); struct pglist_data *pgdat = lruvec_pgdat(lruvec); struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; @@ -1923,13 +1905,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, lru_add_drain(); - if (!sc->may_unmap) - isolate_mode |= ISOLATE_UNMAPPED; - spin_lock_irq(&pgdat->lru_lock); nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &page_list, - &nr_scanned, sc, isolate_mode, lru); + &nr_scanned, sc, lru); __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken); reclaim_stat->recent_scanned[file] += nr_taken; @@ -2011,9 +1990,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, * processes, from rmap. * * If the pages are mostly unmapped, the processing is fast and it is - * appropriate to hold zone_lru_lock across the whole operation. But if + * appropriate to hold pgdat->lru_lock across the whole operation. But if * the pages are mapped, the processing is slow (page_referenced()) so we - * should drop zone_lru_lock around each page. It's impossible to balance + * should drop pgdat->lru_lock around each page. It's impossible to balance * this, so instead we remove the pages from the LRU while processing them. * It is safe to rely on PG_active against the non-LRU pages in here because * nobody will play with that bit on a non-LRU page. @@ -2086,19 +2065,15 @@ static void shrink_active_list(unsigned long nr_to_scan, struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; unsigned nr_deactivate, nr_activate; unsigned nr_rotated = 0; - isolate_mode_t isolate_mode = 0; int file = is_file_lru(lru); struct pglist_data *pgdat = lruvec_pgdat(lruvec); lru_add_drain(); - if (!sc->may_unmap) - isolate_mode |= ISOLATE_UNMAPPED; - spin_lock_irq(&pgdat->lru_lock); nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &l_hold, - &nr_scanned, sc, isolate_mode, lru); + &nr_scanned, sc, lru); __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken); reclaim_stat->recent_scanned[file] += nr_taken; @@ -2145,6 +2120,7 @@ static void shrink_active_list(unsigned long nr_to_scan, } ClearPageActive(page); /* we are de-activating */ + SetPageWorkingset(page); list_add(&page->lru, &l_inactive); } @@ -2456,9 +2432,11 @@ out: /* * Scan types proportional to swappiness and * their relative recent reclaim efficiency. + * Make sure we don't miss the last page + * because of a round-off error. */ - scan = div64_u64(scan * fraction[file], - denominator); + scan = DIV64_U64_ROUND_UP(scan * fraction[file], + denominator); break; case SCAN_FILE: case SCAN_ANON: @@ -2742,8 +2720,10 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) shrink_node_memcg(pgdat, memcg, sc, &lru_pages); node_lru_pages += lru_pages; - shrink_slab(sc->gfp_mask, pgdat->node_id, + if (sc->may_shrinkslab) { + shrink_slab(sc->gfp_mask, pgdat->node_id, memcg, sc->priority); + } /* Record the group's reclaim efficiency */ vmpressure(sc->gfp_mask, memcg, false, @@ -2751,16 +2731,15 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) sc->nr_reclaimed - reclaimed); /* - * Direct reclaim and kswapd have to scan all memory - * cgroups to fulfill the overall scan target for the - * node. + * Kswapd have to scan all memory cgroups to fulfill + * the overall scan target for the node. * * Limit reclaim, on the other hand, only cares about * nr_to_reclaim pages to be reclaimed and it will * retry with decreasing priority if one round over the * whole hierarchy is not sufficient. */ - if (!global_reclaim(sc) && + if (!current_is_kswapd() && sc->nr_reclaimed >= sc->nr_to_reclaim) { mem_cgroup_iter_break(root, memcg); break; @@ -3225,6 +3204,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order, .may_writepage = !laptop_mode, .may_unmap = 1, .may_swap = 1, + .may_shrinkslab = 1, }; /* @@ -3269,6 +3249,7 @@ unsigned long mem_cgroup_shrink_node(struct mem_cgroup *memcg, .may_unmap = 1, .reclaim_idx = MAX_NR_ZONES - 1, .may_swap = !noswap, + .may_shrinkslab = 1, }; unsigned long lru_pages; @@ -3302,6 +3283,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, { struct zonelist *zonelist; unsigned long nr_reclaimed; + unsigned long pflags; int nid; unsigned int noreclaim_flag; struct scan_control sc = { @@ -3314,6 +3296,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, .may_writepage = !laptop_mode, .may_unmap = 1, .may_swap = may_swap, + .may_shrinkslab = 1, }; /* @@ -3330,9 +3313,13 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, sc.gfp_mask, sc.reclaim_idx); + psi_memstall_enter(&pflags); noreclaim_flag = memalloc_noreclaim_save(); + nr_reclaimed = do_try_to_free_pages(zonelist, &sc); + memalloc_noreclaim_restore(noreclaim_flag); + psi_memstall_leave(&pflags); trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed); @@ -3360,6 +3347,30 @@ static void age_active_anon(struct pglist_data *pgdat, } while (memcg); } +static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx) +{ + int i; + struct zone *zone; + + /* + * Check for watermark boosts top-down as the higher zones + * are more likely to be boosted. Both watermarks and boosts + * should not be checked at the time time as reclaim would + * start prematurely when there is no boosting and a lower + * zone is balanced. + */ + for (i = classzone_idx; i >= 0; i--) { + zone = pgdat->node_zones + i; + if (!managed_zone(zone)) + continue; + + if (zone->watermark_boost) + return true; + } + + return false; +} + /* * Returns true if there is an eligible zone balanced for the request order * and classzone_idx @@ -3370,6 +3381,10 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx) unsigned long mark = -1; struct zone *zone; + /* + * Check watermarks bottom-up as lower zones are more likely to + * meet watermarks. + */ for (i = 0; i <= classzone_idx; i++) { zone = pgdat->node_zones + i; @@ -3488,7 +3503,7 @@ static bool kswapd_shrink_node(pg_data_t *pgdat, * * kswapd scans the zones in the highmem->normal->dma direction. It skips * zones which have free_pages > high_wmark_pages(zone), but once a zone is - * found to have free_pages <= high_wmark_pages(zone), any page is that zone + * found to have free_pages <= high_wmark_pages(zone), any page in that zone * or lower is eligible for reclaim until at least one usable zone is * balanced. */ @@ -3497,23 +3512,44 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) int i; unsigned long nr_soft_reclaimed; unsigned long nr_soft_scanned; + unsigned long pflags; + unsigned long nr_boost_reclaim; + unsigned long zone_boosts[MAX_NR_ZONES] = { 0, }; + bool boosted; struct zone *zone; struct scan_control sc = { .gfp_mask = GFP_KERNEL, .order = order, - .priority = DEF_PRIORITY, - .may_writepage = !laptop_mode, .may_unmap = 1, - .may_swap = 1, }; + psi_memstall_enter(&pflags); __fs_reclaim_acquire(); count_vm_event(PAGEOUTRUN); + /* + * Account for the reclaim boost. Note that the zone boost is left in + * place so that parallel allocations that are near the watermark will + * stall or direct reclaim until kswapd is finished. + */ + nr_boost_reclaim = 0; + for (i = 0; i <= classzone_idx; i++) { + zone = pgdat->node_zones + i; + if (!managed_zone(zone)) + continue; + + nr_boost_reclaim += zone->watermark_boost; + zone_boosts[i] = zone->watermark_boost; + } + boosted = nr_boost_reclaim; + +restart: + sc.priority = DEF_PRIORITY; do { unsigned long nr_reclaimed = sc.nr_reclaimed; bool raise_priority = true; + bool balanced; bool ret; sc.reclaim_idx = classzone_idx; @@ -3540,13 +3576,40 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) } /* - * Only reclaim if there are no eligible zones. Note that - * sc.reclaim_idx is not used as buffer_heads_over_limit may - * have adjusted it. + * If the pgdat is imbalanced then ignore boosting and preserve + * the watermarks for a later time and restart. Note that the + * zone watermarks will be still reset at the end of balancing + * on the grounds that the normal reclaim should be enough to + * re-evaluate if boosting is required when kswapd next wakes. */ - if (pgdat_balanced(pgdat, sc.order, classzone_idx)) + balanced = pgdat_balanced(pgdat, sc.order, classzone_idx); + if (!balanced && nr_boost_reclaim) { + nr_boost_reclaim = 0; + goto restart; + } + + /* + * If boosting is not active then only reclaim if there are no + * eligible zones. Note that sc.reclaim_idx is not used as + * buffer_heads_over_limit may have adjusted it. + */ + if (!nr_boost_reclaim && balanced) goto out; + /* Limit the priority of boosting to avoid reclaim writeback */ + if (nr_boost_reclaim && sc.priority == DEF_PRIORITY - 2) + raise_priority = false; + + /* + * Do not writeback or swap pages for boosted reclaim. The + * intent is to relieve pressure not issue sub-optimal IO + * from reclaim context. If no pages are reclaimed, the + * reclaim will be aborted. + */ + sc.may_writepage = !laptop_mode && !nr_boost_reclaim; + sc.may_swap = !nr_boost_reclaim; + sc.may_shrinkslab = !nr_boost_reclaim; + /* * Do some background aging of the anon list, to give * pages a chance to be referenced before reclaiming. All @@ -3598,6 +3661,16 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) * progress in reclaiming pages */ nr_reclaimed = sc.nr_reclaimed - nr_reclaimed; + nr_boost_reclaim -= min(nr_boost_reclaim, nr_reclaimed); + + /* + * If reclaim made no progress for a boost, stop reclaim as + * IO cannot be queued and it could be an infinite loop in + * extreme circumstances. + */ + if (nr_boost_reclaim && !nr_reclaimed) + break; + if (raise_priority || !nr_reclaimed) sc.priority--; } while (sc.priority >= 1); @@ -3606,8 +3679,31 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) pgdat->kswapd_failures++; out: + /* If reclaim was boosted, account for the reclaim done in this pass */ + if (boosted) { + unsigned long flags; + + for (i = 0; i <= classzone_idx; i++) { + if (!zone_boosts[i]) + continue; + + /* Increments are under the zone lock */ + zone = pgdat->node_zones + i; + spin_lock_irqsave(&zone->lock, flags); + zone->watermark_boost -= min(zone->watermark_boost, zone_boosts[i]); + spin_unlock_irqrestore(&zone->lock, flags); + } + + /* + * As there is now likely space, wakeup kcompact to defragment + * pageblocks. + */ + wakeup_kcompactd(pgdat, pageblock_order, classzone_idx); + } + snapshot_refaults(NULL, pgdat); __fs_reclaim_release(); + psi_memstall_leave(&pflags); /* * Return the order kswapd stopped reclaiming at as * prepare_kswapd_sleep() takes it into account. If another caller @@ -3833,7 +3929,8 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, /* Hopeless node, leave it to direct reclaim if possible */ if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES || - pgdat_balanced(pgdat, order, classzone_idx)) { + (pgdat_balanced(pgdat, order, classzone_idx) && + !pgdat_watermark_boosted(pgdat, classzone_idx))) { /* * There may be plenty of free memory available, but it's too * fragmented for high-order allocations. Wake up kcompactd @@ -4161,17 +4258,16 @@ int page_evictable(struct page *page) return ret; } -#ifdef CONFIG_SHMEM /** - * check_move_unevictable_pages - check pages for evictability and move to appropriate zone lru list - * @pages: array of pages to check - * @nr_pages: number of pages to check - * - * Checks pages for evictability and moves them to the appropriate lru list. + * check_move_unevictable_pages - check pages for evictability and move to + * appropriate zone lru list + * @pvec: pagevec with lru pages to check * - * This function is only used for SysV IPC SHM_UNLOCK. + * Checks pages for evictability, if an evictable page is in the unevictable + * lru list, moves it to the appropriate evictable lru list. This function + * should be only used for lru pages. */ -void check_move_unevictable_pages(struct page **pages, int nr_pages) +void check_move_unevictable_pages(struct pagevec *pvec) { struct lruvec *lruvec; struct pglist_data *pgdat = NULL; @@ -4179,8 +4275,8 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages) int pgrescued = 0; int i; - for (i = 0; i < nr_pages; i++) { - struct page *page = pages[i]; + for (i = 0; i < pvec->nr; i++) { + struct page *page = pvec->pages[i]; struct pglist_data *pagepgdat = page_pgdat(page); pgscanned++; @@ -4212,4 +4308,4 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages) spin_unlock_irq(&pgdat->lru_lock); } } -#endif /* CONFIG_SHMEM */ +EXPORT_SYMBOL_GPL(check_move_unevictable_pages); |