diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 71 |
1 files changed, 46 insertions, 25 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6f6af835b05b..922836b6a01d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2350,7 +2350,7 @@ static int nr_pcp_free(struct per_cpu_pages *pcp, int high, bool free_high) static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone, bool free_high) { - int high = READ_ONCE(pcp->high); + int high = READ_ONCE(pcp->high_min); if (unlikely(!high || free_high)) return 0; @@ -2689,7 +2689,7 @@ static int nr_pcp_alloc(struct per_cpu_pages *pcp, int order) { int high, batch, max_nr_alloc; - high = READ_ONCE(pcp->high); + high = READ_ONCE(pcp->high_min); batch = READ_ONCE(pcp->batch); /* Check for PCP disabled or boot pageset */ @@ -5296,14 +5296,15 @@ static int zone_batchsize(struct zone *zone) } static int percpu_pagelist_high_fraction; -static int zone_highsize(struct zone *zone, int batch, int cpu_online) +static int zone_highsize(struct zone *zone, int batch, int cpu_online, + int high_fraction) { #ifdef CONFIG_MMU int high; int nr_split_cpus; unsigned long total_pages; - if (!percpu_pagelist_high_fraction) { + if (!high_fraction) { /* * By default, the high value of the pcp is based on the zone * low watermark so that if they are full then background @@ -5316,15 +5317,15 @@ static int zone_highsize(struct zone *zone, int batch, int cpu_online) * value is based on a fraction of the managed pages in the * zone. */ - total_pages = zone_managed_pages(zone) / percpu_pagelist_high_fraction; + total_pages = zone_managed_pages(zone) / high_fraction; } /* * Split the high value across all online CPUs local to the zone. Note * that early in boot that CPUs may not be online yet and that during * CPU hotplug that the cpumask is not yet updated when a CPU is being - * onlined. For memory nodes that have no CPUs, split pcp->high across - * all online CPUs to mitigate the risk that reclaim is triggered + * onlined. For memory nodes that have no CPUs, split the high value + * across all online CPUs to mitigate the risk that reclaim is triggered * prematurely due to pages stored on pcp lists. */ nr_split_cpus = cpumask_weight(cpumask_of_node(zone_to_nid(zone))) + cpu_online; @@ -5352,19 +5353,21 @@ static int zone_highsize(struct zone *zone, int batch, int cpu_online) * However, guaranteeing these relations at all times would require e.g. write * barriers here but also careful usage of read barriers at the read side, and * thus be prone to error and bad for performance. Thus the update only prevents - * store tearing. Any new users of pcp->batch and pcp->high should ensure they - * can cope with those fields changing asynchronously, and fully trust only the - * pcp->count field on the local CPU with interrupts disabled. + * store tearing. Any new users of pcp->batch, pcp->high_min and pcp->high_max + * should ensure they can cope with those fields changing asynchronously, and + * fully trust only the pcp->count field on the local CPU with interrupts + * disabled. * * mutex_is_locked(&pcp_batch_high_lock) required when calling this function * outside of boot time (or some other assurance that no concurrent updaters * exist). */ -static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, - unsigned long batch) +static void pageset_update(struct per_cpu_pages *pcp, unsigned long high_min, + unsigned long high_max, unsigned long batch) { WRITE_ONCE(pcp->batch, batch); - WRITE_ONCE(pcp->high, high); + WRITE_ONCE(pcp->high_min, high_min); + WRITE_ONCE(pcp->high_max, high_max); } static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonestat *pzstats) @@ -5384,20 +5387,21 @@ static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonesta * need to be as careful as pageset_update() as nobody can access the * pageset yet. */ - pcp->high = BOOT_PAGESET_HIGH; + pcp->high_min = BOOT_PAGESET_HIGH; + pcp->high_max = BOOT_PAGESET_HIGH; pcp->batch = BOOT_PAGESET_BATCH; pcp->free_factor = 0; } -static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high, - unsigned long batch) +static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high_min, + unsigned long high_max, unsigned long batch) { struct per_cpu_pages *pcp; int cpu; for_each_possible_cpu(cpu) { pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu); - pageset_update(pcp, high, batch); + pageset_update(pcp, high_min, high_max, batch); } } @@ -5407,19 +5411,34 @@ static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long h */ static void zone_set_pageset_high_and_batch(struct zone *zone, int cpu_online) { - int new_high, new_batch; + int new_high_min, new_high_max, new_batch; new_batch = max(1, zone_batchsize(zone)); - new_high = zone_highsize(zone, new_batch, cpu_online); + if (percpu_pagelist_high_fraction) { + new_high_min = zone_highsize(zone, new_batch, cpu_online, + percpu_pagelist_high_fraction); + /* + * PCP high is tuned manually, disable auto-tuning via + * setting high_min and high_max to the manual value. + */ + new_high_max = new_high_min; + } else { + new_high_min = zone_highsize(zone, new_batch, cpu_online, 0); + new_high_max = zone_highsize(zone, new_batch, cpu_online, + MIN_PERCPU_PAGELIST_HIGH_FRACTION); + } - if (zone->pageset_high == new_high && + if (zone->pageset_high_min == new_high_min && + zone->pageset_high_max == new_high_max && zone->pageset_batch == new_batch) return; - zone->pageset_high = new_high; + zone->pageset_high_min = new_high_min; + zone->pageset_high_max = new_high_max; zone->pageset_batch = new_batch; - __zone_set_pageset_high_and_batch(zone, new_high, new_batch); + __zone_set_pageset_high_and_batch(zone, new_high_min, new_high_max, + new_batch); } void __meminit setup_zone_pageset(struct zone *zone) @@ -5528,7 +5547,8 @@ __meminit void zone_pcp_init(struct zone *zone) */ zone->per_cpu_pageset = &boot_pageset; zone->per_cpu_zonestats = &boot_zonestats; - zone->pageset_high = BOOT_PAGESET_HIGH; + zone->pageset_high_min = BOOT_PAGESET_HIGH; + zone->pageset_high_max = BOOT_PAGESET_HIGH; zone->pageset_batch = BOOT_PAGESET_BATCH; if (populated_zone(zone)) @@ -6430,13 +6450,14 @@ EXPORT_SYMBOL(free_contig_range); void zone_pcp_disable(struct zone *zone) { mutex_lock(&pcp_batch_high_lock); - __zone_set_pageset_high_and_batch(zone, 0, 1); + __zone_set_pageset_high_and_batch(zone, 0, 0, 1); __drain_all_pages(zone, true); } void zone_pcp_enable(struct zone *zone) { - __zone_set_pageset_high_and_batch(zone, zone->pageset_high, zone->pageset_batch); + __zone_set_pageset_high_and_batch(zone, zone->pageset_high_min, + zone->pageset_high_max, zone->pageset_batch); mutex_unlock(&pcp_batch_high_lock); } |