From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01A59C2BA18 for ; Fri, 21 Jun 2024 02:30:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7C6A08D011E; Thu, 20 Jun 2024 22:30:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 729728D0111; Thu, 20 Jun 2024 22:30:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 506D58D011E; Thu, 20 Jun 2024 22:30:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 2D0FD8D0111 for ; Thu, 20 Jun 2024 22:30:40 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id C4AA8140760 for ; Fri, 21 Jun 2024 02:30:39 +0000 (UTC) X-FDA: 82253317398.23.C065E8B Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) by imf23.hostedemail.com (Postfix) with ESMTP id 59E69140010 for ; Fri, 21 Jun 2024 02:30:37 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=LFaaQHuF; spf=pass (imf23.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.172 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718937025; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=HJJW6TUqMjLFLQtgjZhVZ17u48+rsfSnvst6a4mvURc=; b=oKq3puM5olTeyyqOtCoLAMHzATIuJinRi9GJP3ErmseAzNCI8c4uUzdZnZD6bt51croeji EttGEzQfQx8hsYVbyT45hC4/uRr5XrR9nUCiGHCyKew6ZnPku1Qlu8K9W8xzQMJx5XmaHf dXA5LRkw6aUeqXDVjD4NZzFuESCorJw= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=LFaaQHuF; spf=pass (imf23.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.172 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718937025; a=rsa-sha256; cv=none; b=deJdxPB6wgQhWfj36IB8OlTLts2Fme/7vDDgZyHVrFzYIfO15HMI7tn2GW6YKcw1lhiCWK CW9TVyO5Gnpx6sM6mj17+l8bU2dVMfuOFeTKl89oayCwYv0CVP4SkJwmdDFz2DBwZOxFM9 GmQIY1fncIj/S7+EH5Lmh1/6WweUyR4= X-Envelope-To: david@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1718937035; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HJJW6TUqMjLFLQtgjZhVZ17u48+rsfSnvst6a4mvURc=; b=LFaaQHuF1F5v89s/+sweoMkcHWWX5cImYb3O9dUCuBuZSArq+34Y1Fo1ifWMEUyTQowSsp Tywpo9TTBxjaHU79PcH4sIBxeWlytJNLgrrJmFBhpGGVzZrO4rRVpHpOMO7k4o0IpCEj/H xRYTbwz+dtF7LTvlPxfJTCIRaSEiTLY= X-Envelope-To: sfoon.kim@samsung.com X-Envelope-To: akpm@linux-foundation.org X-Envelope-To: linux-mm@kvack.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: sungguk.na@samsung.com X-Envelope-To: sw0312.kim@samsung.com X-Envelope-To: sebuns@gmail.com Message-ID: <9e4bba64-c13f-4157-9258-c9b647ba9dd2@linux.dev> Date: Fri, 21 Jun 2024 10:30:22 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v2] mm: ksm: Consider the number of ksm_mm_slot in the general_profit calculation To: David Hildenbrand , Sung-hun Kim , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: sungguk.na@samsung.com, sw0312.kim@samsung.com, sebuns@gmail.com References: <20240620043914.249768-1-sfoon.kim@samsung.com> <254bf3e0-0056-4593-94ee-8431a1bfc430@redhat.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Chengming Zhou In-Reply-To: <254bf3e0-0056-4593-94ee-8431a1bfc430@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 59E69140010 X-Stat-Signature: nujkxmm6ag5wrud6iigx3trk4sct6u39 X-Rspam-User: X-HE-Tag: 1718937037-599730 X-HE-Meta: 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 mp0ueTKc LsBU6MwdunIwPTQKNfNxjqWUkt0zold0TcFWwDyAt7gIDjnMX+heqkto/LUU83tD4Zuu9EHnXIeGX3cltFqnuNyBiOihtByn3gPc9Ls0eELoWXbMNRiog8cWSfahmgF30nOD2RxEeVVOR09k8vQw/qHIjGNtkZjDXwv/cbsoQrt4FUFWz1klQmmPAHmIrqS18mZP9TTHZ+mQQuk0= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2024/6/21 03:38, David Hildenbrand wrote: > On 20.06.24 06:39, Sung-hun Kim wrote: >> The current version of KSM does not take into account the number of >> used ksm_mm_slot. Therefore, when users want to obtain profits of >> KSM, KSM omits the memory used for allocating ksm_mm_slots. >> >> This patch introduces a new variable to keep track of the number of >> allocated ksm_mm_slots. By doing so, KSM will be able to provide a >> more accurate number of the gains made. > > If you take a look at the calculation explained in > Documentation/admin-guide/mm/ksm.rst, we only care about rmap_items, > which can grow rather substantially in size. > > We also don't consider other metadata, such as the size of the stable > nodes etc. So why should the ksm_mm_slots matter that much that we > should track them and account them? BTW, the size of stable_nodes should be more than these mm_slots, we have one stable_nodes for each KSM page now. But agree, we only care about the rmap_items, which is the majority of used memory resource in KSM.