From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/vmstat: simplify the array size calculation We can replace the array_num * sizeof(array[0]) with sizeof(array) to simplify the code. Link: https://lkml.kernel.org/r/20210715122911.15700-3-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmstat.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/mm/vmstat.c~mm-vmstat-simplify-the-array-size-calculation +++ a/mm/vmstat.c @@ -1891,17 +1891,15 @@ static bool need_update(int cpu) /* * The fast way of checking if there are any vmstat diffs. */ - if (memchr_inv(pzstats->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS * - sizeof(pzstats->vm_stat_diff[0]))) + if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff))) return true; if (last_pgdat == zone->zone_pgdat) continue; last_pgdat = zone->zone_pgdat; n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu); - if (memchr_inv(n->vm_node_stat_diff, 0, NR_VM_NODE_STAT_ITEMS * - sizeof(n->vm_node_stat_diff[0]))) - return true; + if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff))) + return true; } return false; } _