From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1754328AbdCFWVk (ORCPT <rfc822;w@1wt.eu>);
        Mon, 6 Mar 2017 17:21:40 -0500
Received: from mail.linuxfoundation.org ([140.211.169.12]:54526 "EHLO
        mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1753704AbdCFWVb (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 6 Mar 2017 17:21:31 -0500
Date: Mon, 6 Mar 2017 14:11:42 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: David Rientjes <rientjes@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Mel Gorman <mgorman@techsingularity.net>,
        Johannes Weiner <hannes@cmpxchg.org>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [patch -mm] mm, vmstat: suppress pcp stats for unpopulated
 zones in zoneinfo
Message-Id: <20170306141142.f3b22bc0ba43814f546bf3a0@linux-foundation.org>
In-Reply-To: <alpine.DEB.2.10.1703061400500.46428@chino.kir.corp.google.com>
References: <alpine.DEB.2.10.1703021525500.5229@chino.kir.corp.google.com>
        <4acf16c5-c64b-b4f8-9a41-1926eed23fe1@linux.vnet.ibm.com>
        <alpine.DEB.2.10.1703031445340.92298@chino.kir.corp.google.com>
        <alpine.DEB.2.10.1703031451310.98023@chino.kir.corp.google.com>
        <alpine.DEB.2.10.1703061400500.46428@chino.kir.corp.google.com>
X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, 6 Mar 2017 14:03:32 -0800 (PST) David Rientjes <rientjes@google.com> 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?