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 7C27CC433F5 for ; Fri, 1 Apr 2022 01:35:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D72A66B0072; Thu, 31 Mar 2022 21:35:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D22B66B0073; Thu, 31 Mar 2022 21:35:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BE8288D0001; Thu, 31 Mar 2022 21:35:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0222.hostedemail.com [216.40.44.222]) by kanga.kvack.org (Postfix) with ESMTP id B0F5A6B0072 for ; Thu, 31 Mar 2022 21:35:15 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 71E95182DDA01 for ; Fri, 1 Apr 2022 01:35:05 +0000 (UTC) X-FDA: 79306591770.28.D8B8224 Received: from mail-qt1-f178.google.com (mail-qt1-f178.google.com [209.85.160.178]) by imf13.hostedemail.com (Postfix) with ESMTP id 1DB482000E for ; Fri, 1 Apr 2022 01:35:04 +0000 (UTC) Received: by mail-qt1-f178.google.com with SMTP id b18so1044017qtk.13 for ; Thu, 31 Mar 2022 18:35:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:from:to:cc:subject:references:mime-version :content-disposition:in-reply-to; bh=lpUdQnkmu36v27iOFONf3ZseM2a8SDfnThG+6rfaJoI=; b=KO+SHp2hyO5FOzAkbcl5F+prZx3tHpnTrNwmbYGqgzCx6veGUHkwN06CqE3+mjvjmZ BjKqL9SfVkbD2rmXUDA0dMPrqu/HLk6cv2alOIQG7ES2fzgQf9aTeGMK9V80janvKCYe 2mzKk6WBt6I0nBxepgOYHrqkR0VWKWRmsDM5EkwqyVXgB4XuwmC5pMTrG55NfhrzHoRq YjdDmM3rnVjOBSbvAO9k6qbstleYEdvQgcuBoDhsxDjmDCTHYmKugAO0sAawJgdZSzXL 9BchmgKMZuwFk8db12o4TZ5dILX2XbnoaYvJ//yUcvYbUHq10dt+PKBviaIr5vQBYY+y vGeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:from:to:cc:subject:references :mime-version:content-disposition:in-reply-to; bh=lpUdQnkmu36v27iOFONf3ZseM2a8SDfnThG+6rfaJoI=; b=Rx+P3Ad+Df63UD6bdYnxx2xyb2MeTCYZA8q5PxoxHB15O9xdJpY9bPlmzYAgBxFCs8 f7yo5fy8f7oQ/QlW6f+beyzNApxf3Tjjqm4w7A7OA7fHFVUFZZ2X6Fm+EdkH+sMs02y7 pku/dVw2bbFrgs9rrQfAB6rkEOA2nz0ZurjapTcdKGgE7oJQkAzBpG1m4Ry5PqNFaTmD x4r/Zlh/DiaZgj7FlSlLzUB94sy6kdYx1x6X4cfZ+olaX5Xim7B0oFLZdOoVzpupz5mT zm1mAyZmqp09PheMp/Dr5cxJWFOd91JXYKCjWoF/MU+TK5g9YHg8cugpfTMVxAY2hoCc Rexw== X-Gm-Message-State: AOAM53301w5e5LrqcUO+sb+40yujDKQkCCa5sshvMcyF0dHoNmALks08 GPCw+7q3fMG37dKMOkVfWHM= X-Google-Smtp-Source: ABdhPJwH15x56Wp3o6vUCv5Dfe/2WnXWXwFxed/wvSA0j34NCyHKKp9OlGqIXwZ2JCgZnBm8cvUlzQ== X-Received: by 2002:a05:622a:c1:b0:2e1:e281:2ac0 with SMTP id p1-20020a05622a00c100b002e1e2812ac0mr6772498qtw.608.1648776904224; Thu, 31 Mar 2022 18:35:04 -0700 (PDT) Received: from localhost ([193.203.214.57]) by smtp.gmail.com with ESMTPSA id h8-20020ac87d48000000b002e1c6faae9csm834459qtb.28.2022.03.31.18.35.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Mar 2022 18:35:03 -0700 (PDT) Message-ID: <624656c7.1c69fb81.9e8ee.5657@mx.google.com> X-Google-Original-Message-ID: <20220401013500.GA2404167@cgel.zte@gmail.com> Date: Fri, 1 Apr 2022 01:35:00 +0000 From: CGEL To: Bagas Sanjaya Cc: akpm@linux-foundation.org, david@redhat.com, willy@infradead.org, corbet@lwn.net, yang.yang29@zte.com.cn, yang.shi@linux.alibaba.com, dave.hansen@linux.intel.com, saravanand@fb.com, minchan@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, jhubbard@nvidia.com, xu xin , Ran Xiaokai Subject: Re: [PATCH v5] mm/vmstat: add events for ksm cow References: <20220331035616.2390805-1-yang.yang29@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 1DB482000E X-Stat-Signature: deiu91w9dbqcgiri8gtjm9aiymdnk8ea Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=KO+SHp2h; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf13.hostedemail.com: domain of cgel.zte@gmail.com designates 209.85.160.178 as permitted sender) smtp.mailfrom=cgel.zte@gmail.com X-Rspam-User: X-HE-Tag: 1648776904-743374 X-Bogosity: Ham, tests=bogofilter, spamicity=0.219577, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 31, 2022 at 06:44:31PM +0700, Bagas Sanjaya wrote: > On 31/03/22 10.56, cgel.zte@gmail.com wrote: > > +Monitoring KSM events > > +===================== > > + > > +There are some counters in /proc/vmstat that may be used to monitor KSM events. > > +KSM might help save memory, it's a tradeoff by may suffering delay on KSM COW > > +or on swapping in copy. Those events could help users evaluate whether or how > > +to use KSM. For example, if cow_ksm increases too fast, user may decrease the > > +range of madvise(, , MADV_MERGEABLE). > > + > > Did you mean "tradeoff between possible delay on KSM COW and swapping > in copy"? > I mean both are tradeoff, or in other words KSM sacrifices time to gain space. KSM COW please see do_wp_page(), KSM swapping in copy see ksm_might_need_to_copy(). Thanks. > -- > An old man doll... just what I always wanted! - Clara