From e815af95f94914993bbad279c71cf5fef9f4eaac Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Tue, 16 Oct 2007 23:25:54 -0700 Subject: [PATCH] oom: change all_unreclaimable zone member to flags Convert the int all_unreclaimable member of struct zone to unsigned long flags. This can now be used to specify several different zone flags such as all_unreclaimable and reclaim_in_progress, which can now be removed and converted to a per-zone flag. Flags are set and cleared as follows: zone_set_flag(struct zone *zone, zone_flags_t flag) zone_clear_flag(struct zone *zone, zone_flags_t flag) Defines the first zone flags, ZONE_ALL_UNRECLAIMABLE and ZONE_RECLAIM_LOCKED, which have the same semantics as the old zone->all_unreclaimable and zone->reclaim_in_progress, respectively. Also converts all current users that set or clear either flag to use the new interface. Helper functions are defined to test the flags: int zone_is_all_unreclaimable(const struct zone *zone) int zone_is_reclaim_locked(const struct zone *zone) All flag operators are of the atomic variety because there are currently readers that are implemented that do not take zone->lock. [akpm@linux-foundation.org: add needed include] Cc: Andrea Arcangeli Acked-by: Christoph Lameter Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 29 +++++++++++++++++++++++++---- mm/page_alloc.c | 8 ++++---- mm/vmscan.c | 25 +++++++++++++------------ mm/vmstat.c | 2 +- 4 files changed, 43 insertions(+), 21 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index f4bfe824834f..bad9486ee0cc 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -262,10 +263,7 @@ struct zone { unsigned long nr_scan_active; unsigned long nr_scan_inactive; unsigned long pages_scanned; /* since last reclaim */ - int all_unreclaimable; /* All pages pinned */ - - /* A count of how many reclaimers are scanning this zone */ - atomic_t reclaim_in_progress; + unsigned long flags; /* zone flags, see below */ /* Zone statistics */ atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; @@ -343,6 +341,29 @@ struct zone { const char *name; } ____cacheline_internodealigned_in_smp; +typedef enum { + ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */ + ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */ +} zone_flags_t; + +static inline void zone_set_flag(struct zone *zone, zone_flags_t flag) +{ + set_bit(flag, &zone->flags); +} +static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag) +{ + clear_bit(flag, &zone->flags); +} + +static inline int zone_is_all_unreclaimable(const struct zone *zone) +{ + return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags); +} +static inline int zone_is_reclaim_locked(const struct zone *zone) +{ + return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags); +} + /* * The "priority" of VM scanning is how much of the queues we will scan in one * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0e3a05fd4734..fd2df29cc645 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -490,7 +490,7 @@ static void free_pages_bulk(struct zone *zone, int count, struct list_head *list, int order) { spin_lock(&zone->lock); - zone->all_unreclaimable = 0; + zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); zone->pages_scanned = 0; while (count--) { struct page *page; @@ -507,7 +507,7 @@ static void free_pages_bulk(struct zone *zone, int count, static void free_one_page(struct zone *zone, struct page *page, int order) { spin_lock(&zone->lock); - zone->all_unreclaimable = 0; + zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); zone->pages_scanned = 0; __free_one_page(page, zone, order); spin_unlock(&zone->lock); @@ -1851,7 +1851,7 @@ void show_free_areas(void) K(zone_page_state(zone, NR_INACTIVE)), K(zone->present_pages), zone->pages_scanned, - (zone->all_unreclaimable ? "yes" : "no") + (zone_is_all_unreclaimable(zone) ? "yes" : "no") ); printk("lowmem_reserve[]:"); for (i = 0; i < MAX_NR_ZONES; i++) @@ -3372,7 +3372,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat, zone->nr_scan_active = 0; zone->nr_scan_inactive = 0; zap_zone_vm_stats(zone); - atomic_set(&zone->reclaim_in_progress, 0); + zone->flags = 0; if (!size) continue; diff --git a/mm/vmscan.c b/mm/vmscan.c index bbd194630c5b..d8893dc2d4eb 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1108,7 +1108,7 @@ static unsigned long shrink_zone(int priority, struct zone *zone, unsigned long nr_to_scan; unsigned long nr_reclaimed = 0; - atomic_inc(&zone->reclaim_in_progress); + zone_set_flag(zone, ZONE_RECLAIM_LOCKED); /* * Add one to `nr_to_scan' just to make sure that the kernel will @@ -1149,7 +1149,7 @@ static unsigned long shrink_zone(int priority, struct zone *zone, throttle_vm_writeout(sc->gfp_mask); - atomic_dec(&zone->reclaim_in_progress); + zone_clear_flag(zone, ZONE_RECLAIM_LOCKED); return nr_reclaimed; } @@ -1187,7 +1187,7 @@ static unsigned long shrink_zones(int priority, struct zone **zones, note_zone_scanning_priority(zone, priority); - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone_is_all_unreclaimable(zone) && priority != DEF_PRIORITY) continue; /* Let kswapd poll it */ sc->all_unreclaimable = 0; @@ -1368,7 +1368,8 @@ loop_again: if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone_is_all_unreclaimable(zone) && + priority != DEF_PRIORITY) continue; if (!zone_watermark_ok(zone, order, zone->pages_high, @@ -1403,7 +1404,8 @@ loop_again: if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone_is_all_unreclaimable(zone) && + priority != DEF_PRIORITY) continue; if (!zone_watermark_ok(zone, order, zone->pages_high, @@ -1424,12 +1426,13 @@ loop_again: lru_pages); nr_reclaimed += reclaim_state->reclaimed_slab; total_scanned += sc.nr_scanned; - if (zone->all_unreclaimable) + if (zone_is_all_unreclaimable(zone)) continue; if (nr_slab == 0 && zone->pages_scanned >= (zone_page_state(zone, NR_ACTIVE) + zone_page_state(zone, NR_INACTIVE)) * 6) - zone->all_unreclaimable = 1; + zone_set_flag(zone, + ZONE_ALL_UNRECLAIMABLE); /* * If we've done a decent amount of scanning and * the reclaim ratio is low, start doing writepage @@ -1595,7 +1598,7 @@ static unsigned long shrink_all_zones(unsigned long nr_pages, int prio, if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && prio != DEF_PRIORITY) + if (zone_is_all_unreclaimable(zone) && prio != DEF_PRIORITY) continue; /* For pass = 0 we don't shrink the active list */ @@ -1919,10 +1922,8 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) * not have reclaimable pages and if we should not delay the allocation * then do not scan. */ - if (!(gfp_mask & __GFP_WAIT) || - zone->all_unreclaimable || - atomic_read(&zone->reclaim_in_progress) > 0 || - (current->flags & PF_MEMALLOC)) + if (!(gfp_mask & __GFP_WAIT) || zone_is_all_unreclaimable(zone) || + zone_is_reclaim_locked(zone) || (current->flags & PF_MEMALLOC)) return 0; /* diff --git a/mm/vmstat.c b/mm/vmstat.c index 3b5e9043e7db..4651bf153f35 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -704,7 +704,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, "\n all_unreclaimable: %u" "\n prev_priority: %i" "\n start_pfn: %lu", - zone->all_unreclaimable, + zone_is_all_unreclaimable(zone), zone->prev_priority, zone->zone_start_pfn); seq_putc(m, '\n'); -- 2.20.1