Re: [patch -mm] mm, vmstat: suppress pcp stats for unpopulated zones in zoneinfo

[Andrew Morton]

On Mon, 6 Mar 2017 14:03:32 -0800 (PST) David Rientjes <rientjes@xxxxxxxxxx> wrote:

> After "mm, vmstat: print non-populated zones in zoneinfo", /proc/zoneinfo 
> will show unpopulated zones.
> 
> The per-cpu pageset statistics are not relevant for unpopulated zones and 
> can be potentially lengthy, so supress them when they are not interesting.
> 
> Also moves lowmem reserve protection information above pcp stats since it 
> is relevant for all zones per vm.lowmem_reserve_ratio.

Well it's not strictly back-compatible, but /proc/zoneinfo is such a
mess that parsers will be few and hopefully smart enough to handle
this.

btw,

  pagesets
    cpu: 0
              count: 118
              high:  186
              batch: 31
  vm stats threshold: 72
    cpu: 1
              count: 53
              high:  186
              batch: 31
  vm stats threshold: 72

Should the "vm stats threshold" thing be indented further?

Do we need to print it out N times anyway?  Can different CPUs have
different values?