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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92250C433F5 for ; Fri, 1 Apr 2022 01:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243793AbiDABg6 (ORCPT ); Thu, 31 Mar 2022 21:36:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238249AbiDABgy (ORCPT ); Thu, 31 Mar 2022 21:36:54 -0400 Received: from mail-qt1-x82d.google.com (mail-qt1-x82d.google.com [IPv6:2607:f8b0:4864:20::82d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A889240598; Thu, 31 Mar 2022 18:35:05 -0700 (PDT) Received: by mail-qt1-x82d.google.com with SMTP id bp39so1073021qtb.6; Thu, 31 Mar 2022 18:35:05 -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=zlNZE71L+t1g0eILpIqXCKl4DFOZ5nZSnwiATL5cKYZazy4tvi6Fxy2ZCAC43PpMpb aAbSTO8LjD1RdU7CfV18+9WNPLLJ6Xh+jkkllPZpdVeC9zSRjwXxe4N3guaz6vzC/8Ze UPHXvCrszYzvn2/GTmhgUSqe4Xuy00y3CLrg+QgaFj0j6lXzb0d6nR/ub8eLOa1GizLZ dLV80IGPVbOoZwhL/ElHXW7RoIH1MJQqN6hJEM1q8mktvz2tOgsSHqrxiFmbeGrqXtO8 Mu3T1KXYUV/OuKuKcrElq1ezpOJ2NGcNF2d80vSBL3CFS+zQoUMIEmtMHDiO2Eavtbew PSKg== X-Gm-Message-State: AOAM533KDi6HaKjMU3WsrYwvH90++vOmZF661/XssPlBvhBE+k8qVg2u GvHYoOm8wujNdjfHGvuM1rM= 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: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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