On 2017年12月19日 20:28, Michal Hocko wrote:
> On Tue 19-12-17 14:39:22, Kemi Wang wrote:
>> There is not really any use to get NUMA stats separated by zone, and
>> current per-zone NUMA stats is only consumed in /proc/zoneinfo. For code
>> cleanup purpose, we move NUMA stats from per-zone to per-node and reuse the
>> existed per-cpu infrastructure.
>
> Let's hope that nobody really depends on the per-zone numbers. It would
> be really strange as those counters are inherently per-node and that is
> what users should care about but who knows...
>
> Anyway, I hoped we could get rid of NR_VM_NUMA_STAT_ITEMS but your patch
> keeps it and follow up patches even use it further. I will comment on
> those separately but this still makes these few counters really special
> which I think is wrong.
>
Well, that's what I can think of to keep a balance between performance
and simplification. If you have a better idea, please post it and
I will follow that surely.
>> Suggested-by: Andi Kleen <a...@linux.intel.com>
>> Suggested-by: Michal Hocko <mho...@kernel.com>
>> Signed-off-by: Kemi Wang <kemi.w...@intel.com>
>
> I have to fully grasp the rest of the series before I'll give my Ack,
> but I _really_ like the simplification this adds to the code. I believe
> it can be even simpler.
>
>> ---
>> drivers/base/node.c | 23 +++----
>> include/linux/mmzone.h | 27 ++++----
>> include/linux/vmstat.h | 31 ---------
>> mm/mempolicy.c | 2 +-
>> mm/page_alloc.c | 16 +++--
>> mm/vmstat.c | 177
>> +++++--------------------------------------------
>> 6 files changed, 46 insertions(+), 230 deletions(-)
>>
>> diff --git a/drivers/base/node.c b/drivers/base/node.c
>> index ee090ab..a045ea1 100644
>> --- a/drivers/base/node.c
>> +++ b/drivers/base/node.c
>> @@ -169,13 +169,14 @@ static ssize_t node_read_numastat(struct device *dev,
>> "interleave_hit %lu\n"
>> "local_node %lu\n"
>> "other_node %lu\n",
>> - sum_zone_numa_state(dev->id, NUMA_HIT),
>> - sum_zone_numa_state(dev->id, NUMA_MISS),
>> - sum_zone_numa_state(dev->id, NUMA_FOREIGN),
>> - sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT),
>> - sum_zone_numa_state(dev->id, NUMA_LOCAL),
>> - sum_zone_numa_state(dev->id, NUMA_OTHER));
>> + node_page_state(NODE_DATA(dev->id), NUMA_HIT),
>> + node_page_state(NODE_DATA(dev->id), NUMA_MISS),
>> + node_page_state(NODE_DATA(dev->id), NUMA_FOREIGN),
>> + node_page_state(NODE_DATA(dev->id), NUMA_INTERLEAVE_HIT),
>> + node_page_state(NODE_DATA(dev->id), NUMA_LOCAL),
>> + node_page_state(NODE_DATA(dev->id), NUMA_OTHER));
>> }
>> +
>> static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
>>
>> static ssize_t node_read_vmstat(struct device *dev,
>> @@ -190,17 +191,9 @@ static ssize_t node_read_vmstat(struct device *dev,
>> n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
>> sum_zone_node_page_state(nid, i));
>>
>> -#ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
>> - n += sprintf(buf+n, "%s %lu\n",
>> - vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
>> - sum_zone_numa_state(nid, i));
>> -#endif
>> -
>> for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
>> n += sprintf(buf+n, "%s %lu\n",
>> - vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
>> - NR_VM_NUMA_STAT_ITEMS],
>> + vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
>> node_page_state(pgdat, i));
>>
>> return n;
>> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
>> index 67f2e3c..c06d880 100644
>> --- a/include/linux/mmzone.h
>> +++ b/include/linux/mmzone.h
>> @@ -115,20 +115,6 @@ struct zone_padding {
>> #define ZONE_PADDING(name)
>> #endif
>>
>> -#ifdef CONFIG_NUMA
>> -enum numa_stat_item {
>> - NUMA_HIT, /* allocated in intended node */
>> - NUMA_MISS, /* allocated in non intended node */
>> - NUMA_FOREIGN, /* was intended here, hit elsewhere */
>> - NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
>> - NUMA_LOCAL, /* allocation from local node */
>> - NUMA_OTHER, /* allocation from other node */
>> - NR_VM_NUMA_STAT_ITEMS
>> -};
>> -#else
>> -#define NR_VM_NUMA_STAT_ITEMS 0
>> -#endif
>> -
>> enum zone_stat_item {
>> /* First 128 byte cacheline (assuming 64 bit words) */
>> NR_FREE_PAGES,
>> @@ -151,7 +137,18 @@ enum zone_stat_item {
>> NR_VM_ZONE_STAT_ITEMS };
>>
>> enum node_stat_item {
>> - NR_LRU_BASE,
>> +#ifdef CONFIG_NUMA
>> + NUMA_HIT, /* allocated in intended node */
>> + NUMA_MISS, /* allocated in non intended node */
>> + NUMA_FOREIGN, /* was intended here, hit elsewhere */
>> + NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
>> + NUMA_LOCAL, /* allocation from local node */
>> + NUMA_OTHER, /* allocation from other node */
>> + NR_VM_NUMA_STAT_ITEMS,
>> +#else
>> +#define NR_VM_NUMA_STAT_ITEMS 0
>> +#endif
>> + NR_LRU_BASE = NR_VM_NUMA_STAT_ITEMS,
>> NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
>> NR_ACTIVE_ANON, /* " " " " " */
>> NR_INACTIVE_FILE, /* " " " " " */
>> diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
>> index 1779c98..80bf290 100644
>> --- a/include/linux/vmstat.h
>> +++ b/include/linux/vmstat.h
>> @@ -118,37 +118,8 @@ static inline void vm_events_fold_cpu(int cpu)
>> * Zone and node-based page accounting with per cpu differentials.
>> */
>> extern atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS];
>> -extern atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS];
>> extern atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS];
>>
>> -#ifdef CONFIG_NUMA
>> -static inline void zone_numa_state_add(long x, struct zone *zone,
>> - enum numa_stat_item item)
>> -{
>> - atomic_long_add(x, &zone->vm_numa_stat[item]);
>> - atomic_long_add(x, &vm_numa_stat[item]);
>> -}
>> -
>> -static inline unsigned long global_numa_state(enum numa_stat_item item)
>> -{
>> - long x = atomic_long_read(&vm_numa_stat[item]);
>> -
>> - return x;
>> -}
>> -
>> -static inline unsigned long zone_numa_state_snapshot(struct zone *zone,
>> - enum numa_stat_item item)
>> -{
>> - long x = atomic_long_read(&zone->vm_numa_stat[item]);
>> - int cpu;
>> -
>> - for_each_online_cpu(cpu)
>> - x += per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item];
>> -
>> - return x;
>> -}
>> -#endif /* CONFIG_NUMA */
>> -
>> static inline void zone_page_state_add(long x, struct zone *zone,
>> enum zone_stat_item item)
>> {
>> @@ -234,10 +205,8 @@ static inline unsigned long
>> node_page_state_snapshot(pg_data_t *pgdat,
>>
>>
>> #ifdef CONFIG_NUMA
>> -extern void __inc_numa_state(struct zone *zone, enum numa_stat_item item);
>> extern unsigned long sum_zone_node_page_state(int node,
>> enum zone_stat_item item);
>> -extern unsigned long sum_zone_numa_state(int node, enum numa_stat_item
>> item);
>> extern unsigned long node_page_state(struct pglist_data *pgdat,
>> enum node_stat_item item);
>> #else
>> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
>> index 4ce44d3..b2293e3 100644
>> --- a/mm/mempolicy.c
>> +++ b/mm/mempolicy.c
>> @@ -1920,7 +1920,7 @@ static struct page *alloc_page_interleave(gfp_t gfp,
>> unsigned order,
>> return page;
>> if (page && page_to_nid(page) == nid) {
>> preempt_disable();
>> - __inc_numa_state(page_zone(page), NUMA_INTERLEAVE_HIT);
>> + inc_node_state(page_pgdat(page), NUMA_INTERLEAVE_HIT);
>> preempt_enable();
>> }
>> return page;
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 7e5e775..81e8d8f 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -2793,22 +2793,24 @@ int __isolate_free_page(struct page *page, unsigned
>> int order)
>> static inline void zone_statistics(struct zone *preferred_zone, struct zone
>> *z)
>> {
>> #ifdef CONFIG_NUMA
>> - enum numa_stat_item local_stat = NUMA_LOCAL;
>> + int preferred_nid = preferred_zone->node;
>> + int nid = z->node;
>> + enum node_stat_item local_stat = NUMA_LOCAL;
>>
>> /* skip numa counters update if numa stats is disabled */
>> if (!static_branch_likely(&vm_numa_stat_key))
>> return;
>>
>> - if (z->node != numa_node_id())
>> + if (nid != numa_node_id())
>> local_stat = NUMA_OTHER;
>>
>> - if (z->node == preferred_zone->node)
>> - __inc_numa_state(z, NUMA_HIT);
>> + if (nid == preferred_nid)
>> + inc_node_state(NODE_DATA(nid), NUMA_HIT);
>> else {
>> - __inc_numa_state(z, NUMA_MISS);
>> - __inc_numa_state(preferred_zone, NUMA_FOREIGN);
>> + inc_node_state(NODE_DATA(nid), NUMA_MISS);
>> + inc_node_state(NODE_DATA(preferred_nid), NUMA_FOREIGN);
>> }
>> - __inc_numa_state(z, local_stat);
>> + inc_node_state(NODE_DATA(nid), local_stat);
>> #endif
>> }
>>
>> diff --git a/mm/vmstat.c b/mm/vmstat.c
>> index 40b2db6..1dd12ae 100644
>> --- a/mm/vmstat.c
>> +++ b/mm/vmstat.c
>> @@ -30,46 +30,44 @@
>>
>> #include "internal.h"
>>
>> -#define NUMA_STATS_THRESHOLD (U16_MAX - 2)
>> -
>> #ifdef CONFIG_NUMA
>> int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
>>
>> -/* zero numa counters within a zone */
>> -static void zero_zone_numa_counters(struct zone *zone)
>> +/* zero numa stats within a node */
>> +static void zero_node_numa_stats(int node)
>> {
>> int item, cpu;
>>
>> for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) {
>> - atomic_long_set(&zone->vm_numa_stat[item], 0);
>> + atomic_long_set(&(NODE_DATA(node)->vm_stat[item]), 0);
>> for_each_online_cpu(cpu)
>> - per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item]
>> - = 0;
>> + per_cpu_ptr(NODE_DATA(node)->per_cpu_nodestats,
>> + cpu)->vm_node_stat_diff[item] = 0;
>> }
>> }
>>
>> -/* zero numa counters of all the populated zones */
>> -static void zero_zones_numa_counters(void)
>> +/* zero numa stats of all the online nodes */
>> +static void zero_nodes_numa_stats(void)
>> {
>> - struct zone *zone;
>> + int node;
>>
>> - for_each_populated_zone(zone)
>> - zero_zone_numa_counters(zone);
>> + for_each_online_node(node)
>> + zero_node_numa_stats(node);
>> }
>>
>> -/* zero global numa counters */
>> -static void zero_global_numa_counters(void)
>> +/* zero global numa stats */
>> +static void zero_global_numa_stats(void)
>> {
>> int item;
>>
>> for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++)
>> - atomic_long_set(&vm_numa_stat[item], 0);
>> + atomic_long_set(&vm_node_stat[item], 0);
>> }
>>
>> static void invalid_numa_statistics(void)
>> {
>> - zero_zones_numa_counters();
>> - zero_global_numa_counters();
>> + zero_nodes_numa_stats();
>> + zero_global_numa_stats();
>> }
>>
>> static DEFINE_MUTEX(vm_numa_stat_lock);
>> @@ -160,10 +158,8 @@ void vm_events_fold_cpu(int cpu)
>> * vm_stat contains the global counters
>> */
>> atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS]
>> __cacheline_aligned_in_smp;
>> -atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS]
>> __cacheline_aligned_in_smp;
>> atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS]
>> __cacheline_aligned_in_smp;
>> EXPORT_SYMBOL(vm_zone_stat);
>> -EXPORT_SYMBOL(vm_numa_stat);
>> EXPORT_SYMBOL(vm_node_stat);
>>
>> #ifdef CONFIG_SMP
>> @@ -679,32 +675,6 @@ EXPORT_SYMBOL(dec_node_page_state);
>> * Fold a differential into the global counters.
>> * Returns the number of counters updated.
>> */
>> -#ifdef CONFIG_NUMA
>> -static int fold_diff(int *zone_diff, int *numa_diff, int *node_diff)
>> -{
>> - int i;
>> - int changes = 0;
>> -
>> - for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
>> - if (zone_diff[i]) {
>> - atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
>> - changes++;
>> - }
>> -
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
>> - if (numa_diff[i]) {
>> - atomic_long_add(numa_diff[i], &vm_numa_stat[i]);
>> - changes++;
>> - }
>> -
>> - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
>> - if (node_diff[i]) {
>> - atomic_long_add(node_diff[i], &vm_node_stat[i]);
>> - changes++;
>> - }
>> - return changes;
>> -}
>> -#else
>> static int fold_diff(int *zone_diff, int *node_diff)
>> {
>> int i;
>> @@ -723,7 +693,6 @@ static int fold_diff(int *zone_diff, int *node_diff)
>> }
>> return changes;
>> }
>> -#endif /* CONFIG_NUMA */
>>
>> /*
>> * Update the zone counters for the current cpu.
>> @@ -747,9 +716,6 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
>> struct zone *zone;
>> int i;
>> int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
>> -#ifdef CONFIG_NUMA
>> - int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
>> -#endif
>> int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
>> int changes = 0;
>>
>> @@ -771,18 +737,6 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
>> }
>> }
>> #ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
>> - int v;
>> -
>> - v = this_cpu_xchg(p->vm_numa_stat_diff[i], 0);
>> - if (v) {
>> -
>> - atomic_long_add(v, &zone->vm_numa_stat[i]);
>> - global_numa_diff[i] += v;
>> - __this_cpu_write(p->expire, 3);
>> - }
>> - }
>> -
>> if (do_pagesets) {
>> cond_resched();
>> /*
>> @@ -829,12 +783,7 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
>> }
>> }
>>
>> -#ifdef CONFIG_NUMA
>> - changes += fold_diff(global_zone_diff, global_numa_diff,
>> - global_node_diff);
>> -#else
>> changes += fold_diff(global_zone_diff, global_node_diff);
>> -#endif
>> return changes;
>> }
>>
>> @@ -849,9 +798,6 @@ void cpu_vm_stats_fold(int cpu)
>> struct zone *zone;
>> int i;
>> int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
>> -#ifdef CONFIG_NUMA
>> - int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
>> -#endif
>> int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
>>
>> for_each_populated_zone(zone) {
>> @@ -868,18 +814,6 @@ void cpu_vm_stats_fold(int cpu)
>> atomic_long_add(v, &zone->vm_stat[i]);
>> global_zone_diff[i] += v;
>> }
>> -
>> -#ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
>> - if (p->vm_numa_stat_diff[i]) {
>> - int v;
>> -
>> - v = p->vm_numa_stat_diff[i];
>> - p->vm_numa_stat_diff[i] = 0;
>> - atomic_long_add(v, &zone->vm_numa_stat[i]);
>> - global_numa_diff[i] += v;
>> - }
>> -#endif
>> }
>>
>> for_each_online_pgdat(pgdat) {
>> @@ -898,11 +832,7 @@ void cpu_vm_stats_fold(int cpu)
>> }
>> }
>>
>> -#ifdef CONFIG_NUMA
>> - fold_diff(global_zone_diff, global_numa_diff, global_node_diff);
>> -#else
>> fold_diff(global_zone_diff, global_node_diff);
>> -#endif
>> }
>>
>> /*
>> @@ -920,36 +850,10 @@ void drain_zonestat(struct zone *zone, struct
>> per_cpu_pageset *pset)
>> atomic_long_add(v, &zone->vm_stat[i]);
>> atomic_long_add(v, &vm_zone_stat[i]);
>> }
>> -
>> -#ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
>> - if (pset->vm_numa_stat_diff[i]) {
>> - int v = pset->vm_numa_stat_diff[i];
>> -
>> - pset->vm_numa_stat_diff[i] = 0;
>> - atomic_long_add(v, &zone->vm_numa_stat[i]);
>> - atomic_long_add(v, &vm_numa_stat[i]);
>> - }
>> -#endif
>> }
>> #endif
>>
>> #ifdef CONFIG_NUMA
>> -void __inc_numa_state(struct zone *zone,
>> - enum numa_stat_item item)
>> -{
>> - struct per_cpu_pageset __percpu *pcp = zone->pageset;
>> - u16 __percpu *p = pcp->vm_numa_stat_diff + item;
>> - u16 v;
>> -
>> - v = __this_cpu_inc_return(*p);
>> -
>> - if (unlikely(v > NUMA_STATS_THRESHOLD)) {
>> - zone_numa_state_add(v, zone, item);
>> - __this_cpu_write(*p, 0);
>> - }
>> -}
>> -
>> /*
>> * Determine the per node value of a stat item. This function
>> * is called frequently in a NUMA machine, so try to be as
>> @@ -969,23 +873,6 @@ unsigned long sum_zone_node_page_state(int node,
>> }
>>
>> /*
>> - * Determine the per node value of a numa stat item. To avoid deviation,
>> - * the per cpu stat number in vm_numa_stat_diff[] is also included.
>> - */
>> -unsigned long sum_zone_numa_state(int node,
>> - enum numa_stat_item item)
>> -{
>> - struct zone *zones = NODE_DATA(node)->node_zones;
>> - int i;
>> - unsigned long count = 0;
>> -
>> - for (i = 0; i < MAX_NR_ZONES; i++)
>> - count += zone_numa_state_snapshot(zones + i, item);
>> -
>> - return count;
>> -}
>> -
>> -/*
>> * Determine the per node value of a stat item.
>> */
>> unsigned long node_page_state(struct pglist_data *pgdat,
>> @@ -1569,8 +1456,7 @@ static void zoneinfo_show_print(struct seq_file *m,
>> pg_data_t *pgdat,
>> seq_printf(m, "\n per-node stats");
>> for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
>> seq_printf(m, "\n %-12s %lu",
>> - vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
>> - NR_VM_NUMA_STAT_ITEMS],
>> + vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
>> node_page_state(pgdat, i));
>> }
>> }
>> @@ -1607,13 +1493,6 @@ static void zoneinfo_show_print(struct seq_file *m,
>> pg_data_t *pgdat,
>> seq_printf(m, "\n %-12s %lu", vmstat_text[i],
>> zone_page_state(zone, i));
>>
>> -#ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
>> - seq_printf(m, "\n %-12s %lu",
>> - vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
>> - zone_numa_state_snapshot(zone, i));
>> -#endif
>> -
>> seq_printf(m, "\n pagesets");
>> for_each_online_cpu(i) {
>> struct per_cpu_pageset *pageset;
>> @@ -1688,7 +1567,6 @@ static void *vmstat_start(struct seq_file *m, loff_t
>> *pos)
>> if (*pos >= ARRAY_SIZE(vmstat_text))
>> return NULL;
>> stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
>> - NR_VM_NUMA_STAT_ITEMS * sizeof(unsigned long) +
>> NR_VM_NODE_STAT_ITEMS * sizeof(unsigned long) +
>> NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
>>
>> @@ -1704,12 +1582,6 @@ static void *vmstat_start(struct seq_file *m, loff_t
>> *pos)
>> v[i] = global_zone_page_state(i);
>> v += NR_VM_ZONE_STAT_ITEMS;
>>
>> -#ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
>> - v[i] = global_numa_state(i);
>> - v += NR_VM_NUMA_STAT_ITEMS;
>> -#endif
>> -
>> for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
>> v[i] = global_node_page_state(i);
>> v += NR_VM_NODE_STAT_ITEMS;
>> @@ -1811,16 +1683,6 @@ int vmstat_refresh(struct ctl_table *table, int write,
>> err = -EINVAL;
>> }
>> }
>> -#ifdef CONFIG_NUMA
>> - for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
>> - val = atomic_long_read(&vm_numa_stat[i]);
>> - if (val < 0) {
>> - pr_warn("%s: %s %ld\n",
>> - __func__, vmstat_text[i +
>> NR_VM_ZONE_STAT_ITEMS], val);
>> - err = -EINVAL;
>> - }
>> - }
>> -#endif
>> if (err)
>> return err;
>> if (write)
>> @@ -1862,9 +1724,6 @@ static bool need_update(int cpu)
>> struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);
>>
>> BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
>> -#ifdef CONFIG_NUMA
>> - BUILD_BUG_ON(sizeof(p->vm_numa_stat_diff[0]) != 2);
>> -#endif
>>
>> /*
>> * The fast way of checking if there are any vmstat diffs.
>> @@ -1872,10 +1731,6 @@ static bool need_update(int cpu)
>> */
>> if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS))
>> return true;
>> -#ifdef CONFIG_NUMA
>> - if (memchr_inv(p->vm_numa_stat_diff, 0, NR_VM_NUMA_STAT_ITEMS))
>> - return true;
>> -#endif
>> }
>> return false;
>> }
>> --
>> 2.7.4
>>
>
