[PATCH 5/6] mm/page_alloc: Batch the accounting updates in the bulk allocator
From: Mel Gorman <hidden>
Date: 2021-03-29 12:08:46
Also in:
linux-mm, lkml
Subsystem:
memory management, memory management - core, memory management - page allocator, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Vlastimil Babka, Linus Torvalds
Now that the zone_statistics are a simple counter that does not require special protection, the bulk allocator accounting updates can be batch updated without requiring IRQs to be disabled. Signed-off-by: Mel Gorman <redacted> --- include/linux/vmstat.h | 8 ++++++++ mm/page_alloc.c | 30 +++++++++++++----------------- 2 files changed, 21 insertions(+), 17 deletions(-)
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index dde4dec4e7dd..8473b8fa9756 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h@@ -246,6 +246,14 @@ __count_numa_event(struct zone *zone, enum numa_stat_item item) raw_cpu_inc(pzstats->vm_numa_event[item]); } +static inline void +__count_numa_events(struct zone *zone, enum numa_stat_item item, long delta) +{ + struct per_cpu_zonestat __percpu *pzstats = zone->per_cpu_zonestats; + + raw_cpu_add(pzstats->vm_numa_event[item], delta); +} + extern void __count_numa_event(struct zone *zone, enum numa_stat_item item); extern unsigned long sum_zone_node_page_state(int node, enum zone_stat_item item);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7eb48632bcac..32c64839c145 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -3398,7 +3398,8 @@ void __putback_isolated_page(struct page *page, unsigned int order, int mt) * * Must be called with interrupts disabled. */ -static inline void zone_statistics(struct zone *preferred_zone, struct zone *z) +static inline void zone_statistics(struct zone *preferred_zone, struct zone *z, + long nr_account) { #ifdef CONFIG_NUMA enum numa_stat_item local_stat = NUMA_LOCAL;
@@ -3411,12 +3412,12 @@ static inline void zone_statistics(struct zone *preferred_zone, struct zone *z) local_stat = NUMA_OTHER; if (zone_to_nid(z) == zone_to_nid(preferred_zone)) - __count_numa_event(z, NUMA_HIT); + __count_numa_events(z, NUMA_HIT, nr_account); else { - __count_numa_event(z, NUMA_MISS); - __count_numa_event(preferred_zone, NUMA_FOREIGN); + __count_numa_events(z, NUMA_MISS, nr_account); + __count_numa_events(preferred_zone, NUMA_FOREIGN, nr_account); } - __count_numa_event(z, local_stat); + __count_numa_events(z, local_stat, nr_account); #endif }
@@ -3462,7 +3463,7 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone, page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list); if (page) { __count_zid_vm_events(PGALLOC, page_zonenum(page), 1); - zone_statistics(preferred_zone, zone); + zone_statistics(preferred_zone, zone, 1); } local_unlock_irqrestore(&pagesets.lock, flags); return page;
@@ -3523,7 +3524,7 @@ struct page *rmqueue(struct zone *preferred_zone, get_pcppage_migratetype(page)); __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); - zone_statistics(preferred_zone, zone); + zone_statistics(preferred_zone, zone, 1); local_irq_restore(flags); out:
@@ -5006,7 +5007,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, struct alloc_context ac; gfp_t alloc_gfp; unsigned int alloc_flags; - int nr_populated = 0; + int nr_populated = 0, nr_account = 0; if (unlikely(nr_pages <= 0)) return 0;
@@ -5079,15 +5080,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, goto failed_irq; break; } - - /* - * Ideally this would be batched but the best way to do - * that cheaply is to first convert zone_statistics to - * be inaccurate per-cpu counter like vm_events to avoid - * a RMW cycle then do the accounting with IRQs enabled. - */ - __count_zid_vm_events(PGALLOC, zone_idx(zone), 1); - zone_statistics(ac.preferred_zoneref->zone, zone); + nr_account++; prep_new_page(page, 0, gfp, 0); if (page_list)
@@ -5097,6 +5090,9 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, nr_populated++; } + __count_zid_vm_events(PGALLOC, zone_idx(zone), nr_account); + zone_statistics(ac.preferred_zoneref->zone, zone, nr_account); + local_unlock_irqrestore(&pagesets.lock, flags); return nr_populated;
--
2.26.2