Re: [PATCH 02/16] mm: vmstat: use s32 for vm_node_stat_diff in struct per_cpu_nodestat

From: Christopher Lameter
Date: Sun Oct 20 2019 - 18:49:34 EST

On Thu, 17 Oct 2019, Roman Gushchin wrote:

> But if some counters are in bytes (and the next commit in the series
> will convert slab counters to bytes), it's not gonna work:
> value in bytes can easily exceed s8 without exceeding the threshold
> converted to bytes. So to avoid overfilling per-cpu caches and breaking
> vmstats correctness, let's use s32 instead.

This quardruples the cache footprint of the counters and likely has some
influence on performance.