From: Kemi Wang Date: Fri, 8 Sep 2017 23:12:55 +0000 (-0700) Subject: mm: consider the number in local CPUs when reading NUMA stats X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=638032224ed762a29baca1fc37f1168efc2554ae;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git mm: consider the number in local CPUs when reading NUMA stats To avoid deviation, the per cpu number of NUMA stats in vm_numa_stat_diff[] is included when a user *reads* the NUMA stats. Since NUMA stats does not be read by users frequently, and kernel does not need it to make a decision, it will not be a problem to make the readers more expensive. Link: http://lkml.kernel.org/r/1503568801-21305-4-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang Reported-by: Jesper Dangaard Brouer Acked-by: Mel Gorman Cc: Aaron Lu Cc: Andi Kleen Cc: Christopher Lameter Cc: Dave Hansen Cc: Johannes Weiner Cc: Michal Hocko Cc: Tim Chen Cc: Ying Huang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 9ac82e29948f..ade7cb5f1359 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -125,10 +125,14 @@ static inline unsigned long global_numa_state(enum numa_stat_item item) return x; } -static inline unsigned long zone_numa_state(struct zone *zone, +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; } diff --git a/mm/vmstat.c b/mm/vmstat.c index 153d8129c155..4bb13e72ac97 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -897,6 +897,10 @@ unsigned long sum_zone_node_page_state(int node, return count; } +/* + * 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) { @@ -905,7 +909,7 @@ unsigned long sum_zone_numa_state(int node, unsigned long count = 0; for (i = 0; i < MAX_NR_ZONES; i++) - count += zone_numa_state(zones + i, item); + count += zone_numa_state_snapshot(zones + i, item); return count; } @@ -1536,7 +1540,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, 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(zone, i)); + zone_numa_state_snapshot(zone, i)); #endif seq_printf(m, "\n pagesets"); @@ -1792,6 +1796,7 @@ static bool need_update(int cpu) #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. * This works because the diffs are byte sized items.