From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f69.google.com (mail-oi0-f69.google.com [209.85.218.69]) by kanga.kvack.org (Postfix) with ESMTP id 3D3E36B0005 for ; Mon, 4 Jul 2016 21:20:57 -0400 (EDT) Received: by mail-oi0-f69.google.com with SMTP id u81so275267158oia.3 for ; Mon, 04 Jul 2016 18:20:57 -0700 (PDT) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id g26si1059234ioj.174.2016.07.04.18.20.55 for ; Mon, 04 Jul 2016 18:20:56 -0700 (PDT) Date: Tue, 5 Jul 2016 10:19:57 +0900 From: Minchan Kim Subject: Re: [PATCH 03/31] mm, vmscan: move LRU lists to node Message-ID: <20160705011957.GB28164@bbox> References: <1467403299-25786-1-git-send-email-mgorman@techsingularity.net> <1467403299-25786-4-git-send-email-mgorman@techsingularity.net> MIME-Version: 1.0 In-Reply-To: <1467403299-25786-4-git-send-email-mgorman@techsingularity.net> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Michal Hocko Cc: Andrew Morton , Linux-MM , Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML On Fri, Jul 01, 2016 at 09:01:11PM +0100, Mel Gorman wrote: > This moves the LRU lists from the zone to the node and related data such > as counters, tracing, congestion tracking and writeback tracking. > Unfortunately, due to reclaim and compaction retry logic, it is necessary > to account for the number of LRU pages on both zone and node logic. Most > reclaim logic is based on the node counters but the retry logic uses the > zone counters which do not distinguish inactive and inactive sizes. It active > would be possible to leave the LRU counters on a per-zone basis but it's a > heavier calculation across multiple cache lines that is much more frequent > than the retry checks. > > Other than the LRU counters, this is mostly a mechanical patch but note > that it introduces a number of anomalies. For example, the scans are > per-zone but using per-node counters. We also mark a node as congested > when a zone is congested. This causes weird problems that are fixed later > but is easier to review. > > Signed-off-by: Mel Gorman > Acked-by: Johannes Weiner > Acked-by: Vlastimil Babka > --- > arch/tile/mm/pgtable.c | 8 +- > drivers/base/node.c | 19 +-- > drivers/staging/android/lowmemorykiller.c | 8 +- > include/linux/backing-dev.h | 2 +- > include/linux/memcontrol.h | 16 +-- > include/linux/mm_inline.h | 21 ++- > include/linux/mmzone.h | 69 +++++---- > include/linux/swap.h | 1 + > include/linux/vm_event_item.h | 10 +- > include/linux/vmstat.h | 17 +++ > include/trace/events/vmscan.h | 12 +- > kernel/power/snapshot.c | 10 +- > mm/backing-dev.c | 15 +- > mm/compaction.c | 18 +-- > mm/huge_memory.c | 2 +- > mm/internal.h | 2 +- > mm/khugepaged.c | 4 +- > mm/memcontrol.c | 17 +-- > mm/memory-failure.c | 4 +- > mm/memory_hotplug.c | 2 +- > mm/mempolicy.c | 2 +- > mm/migrate.c | 21 +-- > mm/mlock.c | 2 +- > mm/page-writeback.c | 8 +- > mm/page_alloc.c | 70 ++++----- > mm/swap.c | 50 +++---- > mm/vmscan.c | 226 +++++++++++++++++------------- > mm/vmstat.c | 47 ++++--- > mm/workingset.c | 4 +- > 29 files changed, 387 insertions(+), 300 deletions(-) > > diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c > index c4d5bf841a7f..9e389213580d 100644 > --- a/arch/tile/mm/pgtable.c > +++ b/arch/tile/mm/pgtable.c > @@ -45,10 +45,10 @@ void show_mem(unsigned int filter) > struct zone *zone; > > pr_err("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu free:%lu\n slab:%lu mapped:%lu pagetables:%lu bounce:%lu pagecache:%lu swap:%lu\n", > - (global_page_state(NR_ACTIVE_ANON) + > - global_page_state(NR_ACTIVE_FILE)), > - (global_page_state(NR_INACTIVE_ANON) + > - global_page_state(NR_INACTIVE_FILE)), > + (global_node_page_state(NR_ACTIVE_ANON) + > + global_node_page_state(NR_ACTIVE_FILE)), > + (global_node_page_state(NR_INACTIVE_ANON) + > + global_node_page_state(NR_INACTIVE_FILE)), > global_page_state(NR_FILE_DIRTY), > global_page_state(NR_WRITEBACK), > global_page_state(NR_UNSTABLE_NFS), > diff --git a/drivers/base/node.c b/drivers/base/node.c > index 92d8e090c5b3..b7f01a4a642d 100644 > --- a/drivers/base/node.c > +++ b/drivers/base/node.c > @@ -56,6 +56,7 @@ static ssize_t node_read_meminfo(struct device *dev, > { > int n; > int nid = dev->id; > + struct pglist_data *pgdat = NODE_DATA(nid); > struct sysinfo i; > > si_meminfo_node(&i, nid); > @@ -74,15 +75,15 @@ static ssize_t node_read_meminfo(struct device *dev, > nid, K(i.totalram), > nid, K(i.freeram), > nid, K(i.totalram - i.freeram), > - nid, K(sum_zone_node_page_state(nid, NR_ACTIVE_ANON) + > - sum_zone_node_page_state(nid, NR_ACTIVE_FILE)), > - nid, K(sum_zone_node_page_state(nid, NR_INACTIVE_ANON) + > - sum_zone_node_page_state(nid, NR_INACTIVE_FILE)), > - nid, K(sum_zone_node_page_state(nid, NR_ACTIVE_ANON)), > - nid, K(sum_zone_node_page_state(nid, NR_INACTIVE_ANON)), > - nid, K(sum_zone_node_page_state(nid, NR_ACTIVE_FILE)), > - nid, K(sum_zone_node_page_state(nid, NR_INACTIVE_FILE)), > - nid, K(sum_zone_node_page_state(nid, NR_UNEVICTABLE)), > + nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) + > + node_page_state(pgdat, NR_ACTIVE_FILE)), > + nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) + > + node_page_state(pgdat, NR_INACTIVE_FILE)), > + nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)), > + nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)), > + nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)), > + nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)), > + nid, K(node_page_state(pgdat, NR_UNEVICTABLE)), > nid, K(sum_zone_node_page_state(nid, NR_MLOCK))); > > #ifdef CONFIG_HIGHMEM > diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c > index 24d2745e9437..93dbcc38eb0f 100644 > --- a/drivers/staging/android/lowmemorykiller.c > +++ b/drivers/staging/android/lowmemorykiller.c > @@ -72,10 +72,10 @@ static unsigned long lowmem_deathpending_timeout; > static unsigned long lowmem_count(struct shrinker *s, > struct shrink_control *sc) > { > - return global_page_state(NR_ACTIVE_ANON) + > - global_page_state(NR_ACTIVE_FILE) + > - global_page_state(NR_INACTIVE_ANON) + > - global_page_state(NR_INACTIVE_FILE); > + return global_node_page_state(NR_ACTIVE_ANON) + > + global_node_page_state(NR_ACTIVE_FILE) + > + global_node_page_state(NR_INACTIVE_ANON) + > + global_node_page_state(NR_INACTIVE_FILE); > } > > static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc) > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index c82794f20110..491a91717788 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -197,7 +197,7 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) > } > > long congestion_wait(int sync, long timeout); > -long wait_iff_congested(struct zone *zone, int sync, long timeout); > +long wait_iff_congested(struct pglist_data *pgdat, int sync, long timeout); > int pdflush_proc_obsolete(struct ctl_table *table, int write, > void __user *buffer, size_t *lenp, loff_t *ppos); > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 104efa6874db..1927dcb6921e 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -340,7 +340,7 @@ static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, > struct lruvec *lruvec; > > if (mem_cgroup_disabled()) { > - lruvec = &zone->lruvec; > + lruvec = zone_lruvec(zone); > goto out; > } > > @@ -352,12 +352,12 @@ static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, > * we have to be prepared to initialize lruvec->zone here; lruvec->pgdat > * and if offlined then reonlined, we need to reinitialize it. > */ > - if (unlikely(lruvec->zone != zone)) > - lruvec->zone = zone; > + if (unlikely(lruvec->pgdat != zone->zone_pgdat)) > + lruvec->pgdat = zone->zone_pgdat; > return lruvec; > } > > -struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *); > +struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *); > > bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg); > struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); > @@ -438,7 +438,7 @@ static inline bool mem_cgroup_online(struct mem_cgroup *memcg) > int mem_cgroup_select_victim_node(struct mem_cgroup *memcg); > > void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, > - int nr_pages); > + enum zone_type zid, int nr_pages); > > unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, > int nid, unsigned int lru_mask); > @@ -613,13 +613,13 @@ static inline void mem_cgroup_migrate(struct page *old, struct page *new) > static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone, > struct mem_cgroup *memcg) > { > - return &zone->lruvec; > + return zone_lruvec(zone); > } > > static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page, > - struct zone *zone) > + struct pglist_data *pgdat) > { > - return &zone->lruvec; > + return &pgdat->lruvec; > } > > static inline bool mm_match_cgroup(struct mm_struct *mm, > diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h > index 5bd29ba4f174..9aadcc781857 100644 > --- a/include/linux/mm_inline.h > +++ b/include/linux/mm_inline.h > @@ -23,25 +23,32 @@ static inline int page_is_file_cache(struct page *page) > } > > static __always_inline void __update_lru_size(struct lruvec *lruvec, > - enum lru_list lru, int nr_pages) > + enum lru_list lru, enum zone_type zid, > + int nr_pages) > { > - __mod_zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru, nr_pages); > + struct pglist_data *pgdat = lruvec_pgdat(lruvec); > + > + __mod_node_page_state(pgdat, NR_LRU_BASE + lru, nr_pages); > + __mod_zone_page_state(&pgdat->node_zones[zid], > + NR_ZONE_LRU_BASE + !!is_file_lru(lru), > + nr_pages); > } > > static __always_inline void update_lru_size(struct lruvec *lruvec, > - enum lru_list lru, int nr_pages) > + enum lru_list lru, enum zone_type zid, > + int nr_pages) > { > #ifdef CONFIG_MEMCG > - mem_cgroup_update_lru_size(lruvec, lru, nr_pages); > + mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages); > #else > - __update_lru_size(lruvec, lru, nr_pages); > + __update_lru_size(lruvec, lru, zid, nr_pages); > #endif > } > > static __always_inline void add_page_to_lru_list(struct page *page, > struct lruvec *lruvec, enum lru_list lru) > { > - update_lru_size(lruvec, lru, hpage_nr_pages(page)); > + update_lru_size(lruvec, lru, page_zonenum(page), hpage_nr_pages(page)); > list_add(&page->lru, &lruvec->lists[lru]); > } > > @@ -49,7 +56,7 @@ static __always_inline void del_page_from_lru_list(struct page *page, > struct lruvec *lruvec, enum lru_list lru) > { > list_del(&page->lru); > - update_lru_size(lruvec, lru, -hpage_nr_pages(page)); > + update_lru_size(lruvec, lru, page_zonenum(page), -hpage_nr_pages(page)); > } > > /** > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 2d5087e3c034..258c20758e80 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -111,12 +111,9 @@ enum zone_stat_item { > /* First 128 byte cacheline (assuming 64 bit words) */ > NR_FREE_PAGES, > NR_ALLOC_BATCH, > - NR_LRU_BASE, > - NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ > - NR_ACTIVE_ANON, /* " " " " " */ > - NR_INACTIVE_FILE, /* " " " " " */ > - NR_ACTIVE_FILE, /* " " " " " */ > - NR_UNEVICTABLE, /* " " " " " */ > + NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ > + NR_ZONE_LRU_ANON = NR_ZONE_LRU_BASE, > + NR_ZONE_LRU_FILE, > NR_MLOCK, /* mlock()ed pages found and moved off LRU */ > NR_ANON_PAGES, /* Mapped anonymous pages */ > NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. > @@ -134,12 +131,9 @@ enum zone_stat_item { > NR_VMSCAN_WRITE, > NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ > NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ > - NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ > - NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ > NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ > NR_DIRTIED, /* page dirtyings since bootup */ > NR_WRITTEN, /* page writings since bootup */ > - NR_PAGES_SCANNED, /* pages scanned since last reclaim */ > #if IS_ENABLED(CONFIG_ZSMALLOC) > NR_ZSPAGES, /* allocated in zsmalloc */ > #endif > @@ -161,6 +155,15 @@ enum zone_stat_item { > NR_VM_ZONE_STAT_ITEMS }; > > enum node_stat_item { > + NR_LRU_BASE, > + NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ > + NR_ACTIVE_ANON, /* " " " " " */ > + NR_INACTIVE_FILE, /* " " " " " */ > + NR_ACTIVE_FILE, /* " " " " " */ > + NR_UNEVICTABLE, /* " " " " " */ > + NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ > + NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ > + NR_PAGES_SCANNED, /* pages scanned since last reclaim */ > NR_VM_NODE_STAT_ITEMS > }; > > @@ -219,7 +222,7 @@ struct lruvec { > /* Evictions & activations on the inactive file list */ > atomic_long_t inactive_age; > #ifdef CONFIG_MEMCG > - struct zone *zone; > + struct pglist_data *pgdat; > #endif > }; > > @@ -357,13 +360,6 @@ struct zone { > #ifdef CONFIG_NUMA > int node; > #endif > - > - /* > - * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on > - * this zone's LRU. Maintained by the pageout code. > - */ > - unsigned int inactive_ratio; > - > struct pglist_data *zone_pgdat; > struct per_cpu_pageset __percpu *pageset; > > @@ -495,9 +491,6 @@ struct zone { > > /* Write-intensive fields used by page reclaim */ trivial: We moved lru_lock and lruvec to pgdat so I'm not sure we need ZONE_PADDING, still. > > - /* Fields commonly accessed by the page reclaim scanner */ > - struct lruvec lruvec; > - > /* > * When free pages are below this point, additional steps are taken > * when reading the number of free pages to avoid per-cpu counter > @@ -537,17 +530,20 @@ struct zone { > > enum zone_flags { > ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */ > - ZONE_CONGESTED, /* zone has many dirty pages backed by > + ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */ > +}; > + > +enum pgdat_flags { > + PGDAT_CONGESTED, /* zone has many dirty pages backed by node or pgdat, whatever. > * a congested BDI > */ > - ZONE_DIRTY, /* reclaim scanning has recently found > + PGDAT_DIRTY, /* reclaim scanning has recently found > * many dirty file pages at the tail > * of the LRU. > */ > - ZONE_WRITEBACK, /* reclaim scanning has recently found > + PGDAT_WRITEBACK, /* reclaim scanning has recently found > * many pages under writeback > */ > - ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */ > }; > > static inline unsigned long zone_end_pfn(const struct zone *zone) > @@ -701,12 +697,26 @@ typedef struct pglist_data { > unsigned long first_deferred_pfn; > #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ > > + Unnecessary change. > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > spinlock_t split_queue_lock; > struct list_head split_queue; > unsigned long split_queue_len; > #endif > > + /* Fields commonly accessed by the page reclaim scanner */ > + struct lruvec lruvec; > + > + /* > + * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on > + * this node's LRU. Maintained by the pageout code. > + */ > + unsigned int inactive_ratio; > + > + unsigned long flags; > + > + ZONE_PADDING(_pad2_) > + > /* Per-node vmstats */ > struct per_cpu_nodestat __percpu *per_cpu_nodestats; > atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; > @@ -728,6 +738,11 @@ static inline spinlock_t *zone_lru_lock(struct zone *zone) > return &zone->zone_pgdat->lru_lock; > } > > +static inline struct lruvec *zone_lruvec(struct zone *zone) > +{ > + return &zone->zone_pgdat->lruvec; > +} > + > static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) > { > return pgdat->node_start_pfn + pgdat->node_spanned_pages; > @@ -779,12 +794,12 @@ extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, > > extern void lruvec_init(struct lruvec *lruvec); > > -static inline struct zone *lruvec_zone(struct lruvec *lruvec) > +static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) > { > #ifdef CONFIG_MEMCG > - return lruvec->zone; > + return lruvec->pgdat; > #else > - return container_of(lruvec, struct zone, lruvec); > + return container_of(lruvec, struct pglist_data, lruvec); > #endif > } > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index 0af2bb2028fd..c82f916008b7 100644 > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -317,6 +317,7 @@ extern void lru_cache_add_active_or_unevictable(struct page *page, > > /* linux/mm/vmscan.c */ > extern unsigned long zone_reclaimable_pages(struct zone *zone); > +extern unsigned long pgdat_reclaimable_pages(struct pglist_data *pgdat); > extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, > gfp_t gfp_mask, nodemask_t *mask); > extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > index 42604173f122..1798ff542517 100644 > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -26,11 +26,11 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > PGFREE, PGACTIVATE, PGDEACTIVATE, > PGFAULT, PGMAJFAULT, > PGLAZYFREED, > - FOR_ALL_ZONES(PGREFILL), > - FOR_ALL_ZONES(PGSTEAL_KSWAPD), > - FOR_ALL_ZONES(PGSTEAL_DIRECT), > - FOR_ALL_ZONES(PGSCAN_KSWAPD), > - FOR_ALL_ZONES(PGSCAN_DIRECT), > + PGREFILL, > + PGSTEAL_KSWAPD, > + PGSTEAL_DIRECT, > + PGSCAN_KSWAPD, > + PGSCAN_DIRECT, > PGSCAN_DIRECT_THROTTLE, > #ifdef CONFIG_NUMA > PGSCAN_ZONE_RECLAIM_FAILED, > diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h > index d1744aa3ab9c..ced0c3e9da88 100644 > --- a/include/linux/vmstat.h > +++ b/include/linux/vmstat.h > @@ -178,6 +178,23 @@ static inline unsigned long zone_page_state_snapshot(struct zone *zone, > return x; > } > > +static inline unsigned long node_page_state_snapshot(pg_data_t *pgdat, > + enum zone_stat_item item) enum node_stat_item > +{ > + long x = atomic_long_read(&pgdat->vm_stat[item]); > + > +#ifdef CONFIG_SMP > + int cpu; > + for_each_online_cpu(cpu) > + x += per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->vm_node_stat_diff[item]; > + > + if (x < 0) > + x = 0; > +#endif > + return x; > +} > + > + > #ifdef CONFIG_NUMA > extern unsigned long sum_zone_node_page_state(int node, > enum zone_stat_item item); > @@ -1147,9 +1147,9 @@ static void free_one_page(struct zone *zone, > { > unsigned long nr_scanned; > spin_lock(&zone->lock); > - nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); > + nr_scanned = node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED); > if (nr_scanned) > - __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); > + __mod_node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED, -nr_scanned); > > if (unlikely(has_isolate_pageblock(zone) || > is_migrate_isolate(migratetype))) { > @@ -3526,7 +3526,7 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order, > > available = reclaimable = zone_reclaimable_pages(zone); > available -= DIV_ROUND_UP(no_progress_loops * available, > - MAX_RECLAIM_RETRIES); > + MAX_RECLAIM_RETRIES); Unnecessary change. > available += zone_page_state_snapshot(zone, NR_FREE_PAGES); > > /* > @@ -4331,6 +4331,7 @@ void show_free_areas(unsigned int filter) diff --git a/mm/vmscan.c b/mm/vmscan.c > index e7ffcd259cc4..86a523a761c9 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -191,26 +191,42 @@ static bool sane_reclaim(struct scan_control *sc) > } > #endif > > +/* > + * This misses isolated pages which are not accounted for to save counters. > + * As the data only determines if reclaim or compaction continues, it is > + * not expected that isolated pages will be a dominating factor. When I read below commit, one of the reason it was introduced is whether we should continue to reclaim page or not. At that time, several people wanted it by my guessing [suggested|acked]-by so I think we should notice it to them. Michal? [9f6c399ddc36, consider isolated pages in zone_reclaimable_pages], > + */ > unsigned long zone_reclaimable_pages(struct zone *zone) > { > unsigned long nr; > > - nr = zone_page_state_snapshot(zone, NR_ACTIVE_FILE) + > - zone_page_state_snapshot(zone, NR_INACTIVE_FILE) + > - zone_page_state_snapshot(zone, NR_ISOLATED_FILE); > + nr = zone_page_state_snapshot(zone, NR_ZONE_LRU_FILE); > + if (get_nr_swap_pages() > 0) > + nr += zone_page_state_snapshot(zone, NR_ZONE_LRU_ANON); > + > + return nr; > +} > + -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org