diff options
| -rw-r--r-- | include/linux/mmzone.h | 2 | ||||
| -rw-r--r-- | mm/internal.h | 6 | ||||
| -rw-r--r-- | mm/page_alloc.c | 9 | ||||
| -rw-r--r-- | mm/vmscan.c | 47 | ||||
| -rw-r--r-- | mm/vmstat.c | 2 |
5 files changed, 43 insertions, 23 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 8e02b37..d2c50ab 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -630,6 +630,8 @@ typedef struct pglist_data { int kswapd_order; enum zone_type kswapd_classzone_idx; + int kswapd_failures; /* Number of 'reclaimed == 0' runs */ + #ifdef CONFIG_COMPACTION int kcompactd_max_order; enum zone_type kcompactd_classzone_idx; diff --git a/mm/internal.h b/mm/internal.h index 266efae..e5a0e0e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -81,6 +81,12 @@ static inline void set_page_refcounted(struct page *page) extern unsigned long highest_memmap_pfn; /* + * Maximum number of reclaim retries without progress before the OOM + * killer is consider the only way forward. + */ +#define MAX_RECLAIM_RETRIES 16 + +/* * in mm/vmscan.c: */ extern int isolate_lru_page(struct page *page); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index bd01501..42c0543 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3522,12 +3522,6 @@ bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) } /* - * Maximum number of reclaim retries without any progress before OOM killer - * is consider as the only way to move forward. - */ -#define MAX_RECLAIM_RETRIES 16 - -/* * Checks whether it makes sense to retry the reclaim to make a forward progress * for the given allocation request. * The reclaim feedback represented by did_some_progress (any progress during @@ -4534,7 +4528,8 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask) K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), K(node_page_state(pgdat, NR_UNSTABLE_NFS)), node_page_state(pgdat, NR_PAGES_SCANNED), - !pgdat_reclaimable(pgdat) ? "yes" : "no"); + pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ? + "yes" : "no"); } for_each_populated_zone(zone) { diff --git a/mm/vmscan.c b/mm/vmscan.c index bc8031e..667644e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2620,6 +2620,15 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) } while (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed, sc->nr_scanned - nr_scanned, sc)); + /* + * Kswapd gives up on balancing particular nodes after too + * many failures to reclaim anything from them and goes to + * sleep. On reclaim progress, reset the failure counter. A + * successful direct reclaim run will revive a dormant kswapd. + */ + if (reclaimable) + pgdat->kswapd_failures = 0; + return reclaimable; } @@ -2694,10 +2703,6 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) GFP_KERNEL | __GFP_HARDWALL)) continue; - if (sc->priority != DEF_PRIORITY && - !pgdat_reclaimable(zone->zone_pgdat)) - continue; /* Let kswapd poll it */ - /* * If we already have plenty of memory free for * compaction in this zone, don't free any more. @@ -2817,7 +2822,7 @@ retry: return 0; } -static bool pfmemalloc_watermark_ok(pg_data_t *pgdat) +static bool allow_direct_reclaim(pg_data_t *pgdat) { struct zone *zone; unsigned long pfmemalloc_reserve = 0; @@ -2825,6 +2830,9 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat) int i; bool wmark_ok; + if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES) + return true; + for (i = 0; i <= ZONE_NORMAL; i++) { zone = &pgdat->node_zones[i]; if (!managed_zone(zone) || @@ -2905,7 +2913,7 @@ static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, /* Throttle based on the first usable node */ pgdat = zone->zone_pgdat; - if (pfmemalloc_watermark_ok(pgdat)) + if (allow_direct_reclaim(pgdat)) goto out; break; } @@ -2927,14 +2935,14 @@ static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, */ if (!(gfp_mask & __GFP_FS)) { wait_event_interruptible_timeout(pgdat->pfmemalloc_wait, - pfmemalloc_watermark_ok(pgdat), HZ); + allow_direct_reclaim(pgdat), HZ); goto check_pending; } /* Throttle until kswapd wakes the process */ wait_event_killable(zone->zone_pgdat->pfmemalloc_wait, - pfmemalloc_watermark_ok(pgdat)); + allow_direct_reclaim(pgdat)); check_pending: if (fatal_signal_pending(current)) @@ -3114,7 +3122,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx) /* * The throttled processes are normally woken up in balance_pgdat() as - * soon as pfmemalloc_watermark_ok() is true. But there is a potential + * soon as allow_direct_reclaim() is true. But there is a potential * race between when kswapd checks the watermarks and a process gets * throttled. There is also a potential race if processes get * throttled, kswapd wakes, a large process exits thereby balancing the @@ -3128,6 +3136,10 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx) if (waitqueue_active(&pgdat->pfmemalloc_wait)) wake_up_all(&pgdat->pfmemalloc_wait); + /* Hopeless node, leave it to direct reclaim */ + if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES) + return true; + for (i = 0; i <= classzone_idx; i++) { struct zone *zone = pgdat->node_zones + i; @@ -3214,9 +3226,9 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) count_vm_event(PAGEOUTRUN); do { + unsigned long nr_reclaimed = sc.nr_reclaimed; bool raise_priority = true; - sc.nr_reclaimed = 0; sc.reclaim_idx = classzone_idx; /* @@ -3295,7 +3307,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) * able to safely make forward progress. Wake them */ if (waitqueue_active(&pgdat->pfmemalloc_wait) && - pfmemalloc_watermark_ok(pgdat)) + allow_direct_reclaim(pgdat)) wake_up_all(&pgdat->pfmemalloc_wait); /* Check if kswapd should be suspending */ @@ -3306,10 +3318,14 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) * Raise priority if scanning rate is too low or there was no * progress in reclaiming pages */ - if (raise_priority || !sc.nr_reclaimed) + nr_reclaimed = sc.nr_reclaimed - nr_reclaimed; + if (raise_priority || !nr_reclaimed) sc.priority--; } while (sc.priority >= 1); + if (!sc.nr_reclaimed) + pgdat->kswapd_failures++; + out: /* * Return the order kswapd stopped reclaiming at as @@ -3509,6 +3525,10 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx) if (!waitqueue_active(&pgdat->kswapd_wait)) return; + /* Hopeless node, leave it to direct reclaim */ + if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES) + return; + /* Only wake kswapd if all zones are unbalanced */ for (z = 0; z <= classzone_idx; z++) { zone = pgdat->node_zones + z; @@ -3779,9 +3799,6 @@ int node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order) sum_zone_node_page_state(pgdat->node_id, NR_SLAB_RECLAIMABLE) <= pgdat->min_slab_pages) return NODE_RECLAIM_FULL; - if (!pgdat_reclaimable(pgdat)) - return NODE_RECLAIM_FULL; - /* * Do not scan if the allocation should not be delayed. */ diff --git a/mm/vmstat.c b/mm/vmstat.c index 5a4f5c5..baee70d 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1425,7 +1425,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, "\n node_unreclaimable: %u" "\n start_pfn: %lu" "\n node_inactive_ratio: %u", - !pgdat_reclaimable(zone->zone_pgdat), + pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES, zone->zone_start_pfn, zone->zone_pgdat->inactive_ratio); seq_putc(m, '\n'); |
