diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 1 | ||||
| -rw-r--r-- | mm/migrate.c | 48 | ||||
| -rw-r--r-- | mm/mmzone.c | 21 | ||||
| -rw-r--r-- | mm/page_alloc.c | 35 | ||||
| -rw-r--r-- | mm/vmscan.c | 23 | ||||
| -rw-r--r-- | mm/vmstat.c | 68 |
6 files changed, 127 insertions, 69 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0f900de4c67..a9a534a38ac 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1647,6 +1647,7 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask, if (likely(!ret)) return CHARGE_OK; + res_counter_uncharge(&mem->res, csize); mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw); flags |= MEM_CGROUP_RECLAIM_NOSWAP; } else diff --git a/mm/migrate.c b/mm/migrate.c index 38e7cad782f..2cfa9bf1f0d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -553,7 +553,6 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, int *result = NULL; struct page *newpage = get_new_page(page, private, &result); int remap_swapcache = 1; - int rcu_locked = 0; int charge = 0; struct mem_cgroup *mem = NULL; struct anon_vma *anon_vma = NULL; @@ -605,20 +604,26 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, /* * By try_to_unmap(), page->mapcount goes down to 0 here. In this case, * we cannot notice that anon_vma is freed while we migrates a page. - * This rcu_read_lock() delays freeing anon_vma pointer until the end + * This get_anon_vma() delays freeing anon_vma pointer until the end * of migration. File cache pages are no problem because of page_lock() * File Caches may use write_page() or lock_page() in migration, then, * just care Anon page here. */ if (PageAnon(page)) { - rcu_read_lock(); - rcu_locked = 1; - - /* Determine how to safely use anon_vma */ - if (!page_mapped(page)) { - if (!PageSwapCache(page)) - goto rcu_unlock; - + /* + * Only page_lock_anon_vma() understands the subtleties of + * getting a hold on an anon_vma from outside one of its mms. + */ + anon_vma = page_lock_anon_vma(page); + if (anon_vma) { + /* + * Take a reference count on the anon_vma if the + * page is mapped so that it is guaranteed to + * exist when the page is remapped later + */ + get_anon_vma(anon_vma); + page_unlock_anon_vma(anon_vma); + } else if (PageSwapCache(page)) { /* * We cannot be sure that the anon_vma of an unmapped * swapcache page is safe to use because we don't @@ -633,13 +638,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, */ remap_swapcache = 0; } else { - /* - * Take a reference count on the anon_vma if the - * page is mapped so that it is guaranteed to - * exist when the page is remapped later - */ - anon_vma = page_anon_vma(page); - get_anon_vma(anon_vma); + goto uncharge; } } @@ -656,16 +655,10 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, * free the metadata, so the page can be freed. */ if (!page->mapping) { - if (!PageAnon(page) && page_has_private(page)) { - /* - * Go direct to try_to_free_buffers() here because - * a) that's what try_to_release_page() would do anyway - * b) we may be under rcu_read_lock() here, so we can't - * use GFP_KERNEL which is what try_to_release_page() - * needs to be effective. - */ + VM_BUG_ON(PageAnon(page)); + if (page_has_private(page)) { try_to_free_buffers(page); - goto rcu_unlock; + goto uncharge; } goto skip_unmap; } @@ -679,14 +672,11 @@ skip_unmap: if (rc && remap_swapcache) remove_migration_ptes(page, page); -rcu_unlock: /* Drop an anon_vma reference if we took one */ if (anon_vma) drop_anon_vma(anon_vma); - if (rcu_locked) - rcu_read_unlock(); uncharge: if (!charge) mem_cgroup_end_migration(mem, page, newpage); diff --git a/mm/mmzone.c b/mm/mmzone.c index e35bfb82c85..f5b7d176021 100644 --- a/mm/mmzone.c +++ b/mm/mmzone.c @@ -87,24 +87,3 @@ int memmap_valid_within(unsigned long pfn, return 1; } #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ - -#ifdef CONFIG_SMP -/* Called when a more accurate view of NR_FREE_PAGES is needed */ -unsigned long zone_nr_free_pages(struct zone *zone) -{ - unsigned long nr_free_pages = zone_page_state(zone, NR_FREE_PAGES); - - /* - * While kswapd is awake, it is considered the zone is under some - * memory pressure. Under pressure, there is a risk that - * per-cpu-counter-drift will allow the min watermark to be breached - * potentially causing a live-lock. While kswapd is awake and - * free pages are low, get a better estimate for free pages - */ - if (nr_free_pages < zone->percpu_drift_mark && - !waitqueue_active(&zone->zone_pgdat->kswapd_wait)) - return zone_page_state_snapshot(zone, NR_FREE_PAGES); - - return nr_free_pages; -} -#endif /* CONFIG_SMP */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2bd6f6da38e..985e072a3dd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1459,24 +1459,24 @@ static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) #endif /* CONFIG_FAIL_PAGE_ALLOC */ /* - * Return 1 if free pages are above 'mark'. This takes into account the order + * Return true if free pages are above 'mark'. This takes into account the order * of the allocation. */ -int zone_watermark_ok(struct zone *z, int order, unsigned long mark, - int classzone_idx, int alloc_flags) +static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark, + int classzone_idx, int alloc_flags, long free_pages) { /* free_pages my go negative - that's OK */ long min = mark; - long free_pages = zone_nr_free_pages(z) - (1 << order) + 1; int o; + free_pages -= (1 << order) + 1; if (alloc_flags & ALLOC_HIGH) min -= min / 2; if (alloc_flags & ALLOC_HARDER) min -= min / 4; if (free_pages <= min + z->lowmem_reserve[classzone_idx]) - return 0; + return false; for (o = 0; o < order; o++) { /* At the next order, this order's pages become unavailable */ free_pages -= z->free_area[o].nr_free << o; @@ -1485,9 +1485,28 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark, min >>= 1; if (free_pages <= min) - return 0; + return false; } - return 1; + return true; +} + +bool zone_watermark_ok(struct zone *z, int order, unsigned long mark, + int classzone_idx, int alloc_flags) +{ + return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, + zone_page_state(z, NR_FREE_PAGES)); +} + +bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark, + int classzone_idx, int alloc_flags) +{ + long free_pages = zone_page_state(z, NR_FREE_PAGES); + + if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) + free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); + + return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, + free_pages); } #ifdef CONFIG_NUMA @@ -2441,7 +2460,7 @@ void show_free_areas(void) " all_unreclaimable? %s" "\n", zone->name, - K(zone_nr_free_pages(zone)), + K(zone_page_state(zone, NR_FREE_PAGES)), K(min_wmark_pages(zone)), K(low_wmark_pages(zone)), K(high_wmark_pages(zone)), diff --git a/mm/vmscan.c b/mm/vmscan.c index c5dfabf25f1..3e71cb1ee28 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2082,7 +2082,7 @@ static int sleeping_prematurely(pg_data_t *pgdat, int order, long remaining) if (zone->all_unreclaimable) continue; - if (!zone_watermark_ok(zone, order, high_wmark_pages(zone), + if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone), 0, 0)) return 1; } @@ -2169,7 +2169,7 @@ loop_again: shrink_active_list(SWAP_CLUSTER_MAX, zone, &sc, priority, 0); - if (!zone_watermark_ok(zone, order, + if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone), 0, 0)) { end_zone = i; break; @@ -2215,7 +2215,7 @@ loop_again: * We put equal pressure on every zone, unless one * zone has way too many pages free already. */ - if (!zone_watermark_ok(zone, order, + if (!zone_watermark_ok_safe(zone, order, 8*high_wmark_pages(zone), end_zone, 0)) shrink_zone(priority, zone, &sc); reclaim_state->reclaimed_slab = 0; @@ -2236,7 +2236,7 @@ loop_again: total_scanned > sc.nr_reclaimed + sc.nr_reclaimed / 2) sc.may_writepage = 1; - if (!zone_watermark_ok(zone, order, + if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone), end_zone, 0)) { all_zones_ok = 0; /* @@ -2244,7 +2244,7 @@ loop_again: * means that we have a GFP_ATOMIC allocation * failure risk. Hurry up! */ - if (!zone_watermark_ok(zone, order, + if (!zone_watermark_ok_safe(zone, order, min_wmark_pages(zone), end_zone, 0)) has_under_min_watermark_zone = 1; } @@ -2378,7 +2378,9 @@ static int kswapd(void *p) */ if (!sleeping_prematurely(pgdat, order, remaining)) { trace_mm_vmscan_kswapd_sleep(pgdat->node_id); + restore_pgdat_percpu_threshold(pgdat); schedule(); + reduce_pgdat_percpu_threshold(pgdat); } else { if (remaining) count_vm_event(KSWAPD_LOW_WMARK_HIT_QUICKLY); @@ -2417,16 +2419,17 @@ void wakeup_kswapd(struct zone *zone, int order) if (!populated_zone(zone)) return; - pgdat = zone->zone_pgdat; - if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0)) + if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) return; + pgdat = zone->zone_pgdat; if (pgdat->kswapd_max_order < order) pgdat->kswapd_max_order = order; - trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order); - if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) - return; if (!waitqueue_active(&pgdat->kswapd_wait)) return; + if (zone_watermark_ok_safe(zone, order, low_wmark_pages(zone), 0, 0)) + return; + + trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order); wake_up_interruptible(&pgdat->kswapd_wait); } diff --git a/mm/vmstat.c b/mm/vmstat.c index 355a9e669aa..4d7faebb9b7 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -81,6 +81,30 @@ EXPORT_SYMBOL(vm_stat); #ifdef CONFIG_SMP +static int calculate_pressure_threshold(struct zone *zone) +{ + int threshold; + int watermark_distance; + + /* + * As vmstats are not up to date, there is drift between the estimated + * and real values. For high thresholds and a high number of CPUs, it + * is possible for the min watermark to be breached while the estimated + * value looks fine. The pressure threshold is a reduced value such + * that even the maximum amount of drift will not accidentally breach + * the min watermark + */ + watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone); + threshold = max(1, (int)(watermark_distance / num_online_cpus())); + + /* + * Maximum threshold is 125 + */ + threshold = min(125, threshold); + + return threshold; +} + static int calculate_threshold(struct zone *zone) { int threshold; @@ -159,6 +183,48 @@ static void refresh_zone_stat_thresholds(void) } } +void reduce_pgdat_percpu_threshold(pg_data_t *pgdat) +{ + struct zone *zone; + int cpu; + int threshold; + int i; + + get_online_cpus(); + for (i = 0; i < pgdat->nr_zones; i++) { + zone = &pgdat->node_zones[i]; + if (!zone->percpu_drift_mark) + continue; + + threshold = calculate_pressure_threshold(zone); + for_each_online_cpu(cpu) + per_cpu_ptr(zone->pageset, cpu)->stat_threshold + = threshold; + } + put_online_cpus(); +} + +void restore_pgdat_percpu_threshold(pg_data_t *pgdat) +{ + struct zone *zone; + int cpu; + int threshold; + int i; + + get_online_cpus(); + for (i = 0; i < pgdat->nr_zones; i++) { + zone = &pgdat->node_zones[i]; + if (!zone->percpu_drift_mark) + continue; + + threshold = calculate_threshold(zone); + for_each_online_cpu(cpu) + per_cpu_ptr(zone->pageset, cpu)->stat_threshold + = threshold; + } + put_online_cpus(); +} + /* * For use when we know that interrupts are disabled. */ @@ -826,7 +892,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, "\n scanned %lu" "\n spanned %lu" "\n present %lu", - zone_nr_free_pages(zone), + zone_page_state(zone, NR_FREE_PAGES), min_wmark_pages(zone), low_wmark_pages(zone), high_wmark_pages(zone), |