The fair zone allocation policy interleaves allocation requests between zones to avoid an age inversion problem whereby new pages are reclaimed to balance a zone. Reclaim is now node-based so this should no longer be an issue and the fair zone allocation policy is not free. This patch removes it.
Signed-off-by: Mel Gorman <[email protected]> --- include/linux/mmzone.h | 2 -- mm/internal.h | 1 - mm/page_alloc.c | 69 +------------------------------------------------- mm/vmstat.c | 1 - 4 files changed, 1 insertion(+), 72 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 34050b012409..c551f70951fa 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -114,7 +114,6 @@ struct zone_padding { enum zone_stat_item { /* First 128 byte cacheline (assuming 64 bit words) */ NR_FREE_PAGES, - NR_ALLOC_BATCH, NR_MLOCK, /* mlock()ed pages found and moved off LRU */ NR_SLAB_RECLAIMABLE, NR_SLAB_UNRECLAIMABLE, @@ -521,7 +520,6 @@ struct zone { enum zone_flags { ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */ ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */ - ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */ }; enum pgdat_flags { diff --git a/mm/internal.h b/mm/internal.h index 2e4cee6a8739..a24c4a50c33f 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -429,6 +429,5 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ #define ALLOC_CMA 0x80 /* allow allocations from CMA areas */ -#define ALLOC_FAIR 0x100 /* fair zone allocation */ #endif /* __MM_INTERNAL_H */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2ca5da938972..6b3a78420a5e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1698,11 +1698,6 @@ struct page *buffered_rmqueue(struct zone *preferred_zone, get_freepage_migratetype(page)); } - __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order)); - if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 && - !test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) - set_bit(ZONE_FAIR_DEPLETED, &zone->flags); - __count_zone_vm_events(PGALLOC, zone, 1 << order); zone_statistics(preferred_zone, zone, gfp_flags); local_irq_restore(flags); @@ -1967,11 +1962,6 @@ static void zlc_clear_zones_full(struct zonelist *zonelist) bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); } -static bool zone_local(struct zone *local_zone, struct zone *zone) -{ - return local_zone->node == zone->node; -} - static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) { return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) < @@ -1999,11 +1989,6 @@ static void zlc_clear_zones_full(struct zonelist *zonelist) { } -static bool zone_local(struct zone *local_zone, struct zone *zone) -{ - return true; -} - static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) { return true; @@ -2011,18 +1996,6 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) #endif /* CONFIG_NUMA */ -static void reset_alloc_batches(struct zone *preferred_zone) -{ - struct zone *zone = preferred_zone->zone_pgdat->node_zones; - - do { - mod_zone_page_state(zone, NR_ALLOC_BATCH, - high_wmark_pages(zone) - low_wmark_pages(zone) - - atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); - clear_bit(ZONE_FAIR_DEPLETED, &zone->flags); - } while (zone++ != preferred_zone); -} - /* * get_page_from_freelist goes through the zonelist trying to allocate * a page. @@ -2040,7 +2013,6 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, int did_zlc_setup = 0; /* just call zlc_setup() one time */ bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) && (gfp_mask & __GFP_WRITE); - int nr_fair_skipped = 0; bool zonelist_rescan; struct pglist_data *last_pgdat = NULL; @@ -2063,20 +2035,6 @@ zonelist_scan: !cpuset_zone_allowed(zone, gfp_mask)) continue; /* - * Distribute pages in proportion to the individual - * zone size to ensure fair page aging. The zone a - * page was allocated in should have no effect on the - * time the page has in memory before being reclaimed. - */ - if (alloc_flags & ALLOC_FAIR) { - if (!zone_local(ac->preferred_zone, zone)) - break; - if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) { - nr_fair_skipped++; - continue; - } - } - /* * When allocating a page cache page for writing, we * want to get it from a zone that is within its dirty * limit, such that no single zone holds more than its @@ -2186,24 +2144,6 @@ this_zone_full: zlc_mark_zone_full(zonelist, z); } - /* - * The first pass makes sure allocations are spread fairly within the - * local node. However, the local node might have free pages left - * after the fairness batches are exhausted, and remote zones haven't - * even been considered yet. Try once more without fairness, and - * include remote zones now, before entering the slowpath and waking - * kswapd: prefer spilling to a remote zone over swapping locally. - */ - if (alloc_flags & ALLOC_FAIR) { - alloc_flags &= ~ALLOC_FAIR; - if (nr_fair_skipped) { - zonelist_rescan = true; - reset_alloc_batches(ac->preferred_zone); - } - if (nr_online_nodes > 1) - zonelist_rescan = true; - } - if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) { /* Disable zlc cache for second zonelist scan */ zlc_active = 0; @@ -2808,7 +2748,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, struct zoneref *preferred_zoneref; struct page *page = NULL; unsigned int cpuset_mems_cookie; - int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR; + int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET; gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */ struct alloc_context ac = { .high_zoneidx = gfp_zone(gfp_mask), @@ -4950,9 +4890,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, zone_seqlock_init(zone); zone_pcp_init(zone); - /* For bootup, initialized properly in watermark setup */ - mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages); - if (!size) continue; @@ -5751,10 +5688,6 @@ static void __setup_per_zone_wmarks(void) zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); - __mod_zone_page_state(zone, NR_ALLOC_BATCH, - high_wmark_pages(zone) - low_wmark_pages(zone) - - atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); - setup_zone_migrate_reserve(zone); spin_unlock_irqrestore(&zone->lock, flags); } diff --git a/mm/vmstat.c b/mm/vmstat.c index d805df47d3ae..c3fdd88961ff 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -893,7 +893,6 @@ int fragmentation_index(struct zone *zone, unsigned int order) const char * const vmstat_text[] = { /* enum zone_stat_item countes */ "nr_free_pages", - "nr_alloc_batch", "nr_mlock", "nr_slab_reclaimable", "nr_slab_unreclaimable", -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
