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 S1753798AbbK0Bwm (ORCPT <rfc822;w@1wt.eu>);
	Thu, 26 Nov 2015 20:52:42 -0500
Received: from szxga03-in.huawei.com ([119.145.14.66]:56717 "EHLO
	szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753665AbbK0Bwi (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 26 Nov 2015 20:52:38 -0500
Message-ID: <5657B750.6080908@huawei.com>
Date: Fri, 27 Nov 2015 09:52:16 +0800
From: Xishi Qiu <qiuxishi@huawei.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1
MIME-Version: 1.0
To: Mark Rutland <mark.rutland@arm.com>
CC: zhong jiang <zhongjiang@huawei.com>, <catalin.marinas@arm.com>,
        <will.deacon@arm.com>, <lauraa@codeaurora.org>,
        <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <guohanjun@huawei.com>
Subject: Re: [PATCH] arm64: calculate the various pages number to show
References: <1448458872-39897-1-git-send-email-zhongjiang@huawei.com> <20151125150448.GD12434@leverpostej> <56571FBC.2020300@huawei.com> <20151126154926.GG32343@leverpostej>
In-Reply-To: <20151126154926.GG32343@leverpostej>
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.177.25.179]
X-CFilter-Loop: Reflected
X-Mirapoint-Virus-RAPID-Raw: score=unknown(0),
	refid=str=0001.0A020206.5657B763.000A,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0,
	ip=0.0.0.0,
	so=2013-05-26 15:14:31,
	dmn=2013-03-21 17:37:32
X-Mirapoint-Loop-Id: 7d942a3fe6477f2e6a6a76c52f6bdf58
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 2015/11/26 23:49, Mark Rutland wrote:

> On Thu, Nov 26, 2015 at 11:05:32PM +0800, zhong jiang wrote:
>> On 2015/11/25 23:04, Mark Rutland wrote:
>>> On Wed, Nov 25, 2015 at 09:41:12PM +0800, zhongjiang wrote:
>>>> This patch add the interface to show the number of 4KB or 64KB page,
>>>> aims to statistics the number of different types of pages.
>>>
>>> What is this useful for? Why do we want it?
>>>
>>> What does it account for, just the swapper?
>>>
>>
>> The patch is wirtten when I was in backport set_memory_ro. It can be used to
>> detect whether there is a large page spliting and merging. large page will
>> significantly reduce the TLB miss, and improve the system performance.
> 
> Ok, but typically the user isn't going to be able to do much with this
> information. It feels more like something that should be in the page
> table dump code (where we can calculate the values as we walk the
> tables).
> 
> What is it intended to account for?
> 
> The entire swapper?
> 
> Just the linear mapping?

Hi Mark,

x86 has this information when cat /proc/meminfo, so how about just
like x86 to show it?

Thanks,
Xishi Qiu