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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04068C282C8 for ; Mon, 28 Jan 2019 14:54:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8D3F2147A for ; Mon, 28 Jan 2019 14:54:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548687253; bh=8iwK0U6yXTos4t9tfbpOGS64qvqRgSHy0rTvvz/n5No=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=JdpxhYc4Qf7ZXpw+1A/EmUz4Gh1jVTJuo/XC63MdrFsqEVTB/yd+AahXT7gXywd6C 1Q1CVXBHpHFkPQ7dD8KtEU+5rFlISatedokKYin8wNeBJPtfyPZb9FtI2ViI7AKyaM FQV0ai92czNscRudH74ftZ6pXKeUAKTgsxQT6Qg8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727156AbfA1OyM (ORCPT ); Mon, 28 Jan 2019 09:54:12 -0500 Received: from mail-yw1-f66.google.com ([209.85.161.66]:46640 "EHLO mail-yw1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726744AbfA1OyL (ORCPT ); Mon, 28 Jan 2019 09:54:11 -0500 Received: by mail-yw1-f66.google.com with SMTP id t13so6790242ywe.13; Mon, 28 Jan 2019 06:54:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=RNZJDYS78cHBuBaASjYOvQ9Ko3WT0Xjzjo+ql6w9VUw=; b=sFfs8X5eh/vbWdDTgYPX+K1Lc3aACjsLcTgKaKaELGUI/YJdjtQfD3PP7Thcc8I+V0 VzvrPsx8aPUiZuMdPbmsQKTQlm8B5OwonaiKVCdWYLbtgD20G4MhYNB23vFBBaEZ3Yjy O7rNEQ5dHJSgThfW3GS1ZTUurT9bKKgGyEuWjSF/XaUjdZDETAiUkfA8YuAb2Jy7AQ3N xigKZoDcaSrYEvLmSuUXxyk9Fhlcz/yi8g1+noTMBfJIQcGC+0oAbl/fKUkgHlAuSG/f aB8QarYqlDA3BD/YlMPr+U6FC+gkq8JQi14bksz0cPljK/Ai2pQvV8FEdhh7XENOHITM xTSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=RNZJDYS78cHBuBaASjYOvQ9Ko3WT0Xjzjo+ql6w9VUw=; b=IjujJZkLQHLJX+2AkfleK3t9vMV3m4Znr83ia/x2j18GtYVhwk1dcIQ1owT11T9Lf/ RQX1YKGDX9LvivX3dINtmrW+eegOmAqdzhXj2LAwZP2klB5QkUYR9ypV5zWU/y2p7YAt g6hGrAp1M2HgdfD7BeiGO/TowBSeumJjDUSDQL/LBCZXx1FilqcEXkMsITMvMRy+ftDf EgRukw7bswAIHpEVby8ysLW2BtE9QVRknJXzVFzJHfYaqRS8Faa4NreSzog6WohZLmk0 dksPRFphdfofuTWPLS0kP+ooPoB/tz2yIFwqtj9QwLuhTfEOk+2p107dDaEQhPR6poKc tuQA== X-Gm-Message-State: AJcUukc7smfvneLgJ1bezSICV2UKp2CWioHYVYHZ2qHeviHoVBdrAzDP LQMHNYxFuLO6Z2ND4GyOf+3/e9Hx X-Google-Smtp-Source: ALg8bN7PjAMmDGVJtjlGsZeDU7vwYgN+ZFrDMK6RFaKb28IN5OdoU3lQTnC/InfCKP26mD4Djv0mTw== X-Received: by 2002:a81:ad5a:: with SMTP id l26mr20917165ywk.58.1548687250695; Mon, 28 Jan 2019 06:54:10 -0800 (PST) Received: from localhost ([2620:10d:c091:200::7:a62a]) by smtp.gmail.com with ESMTPSA id p11sm12053273ywm.60.2019.01.28.06.54.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 28 Jan 2019 06:54:09 -0800 (PST) Date: Mon, 28 Jan 2019 06:54:07 -0800 From: Tejun Heo To: Michal Hocko Cc: Johannes Weiner , Chris Down , Andrew Morton , Roman Gushchin , Dennis Zhou , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com Subject: Re: [PATCH 2/2] mm: Consider subtrees in memory.events Message-ID: <20190128145407.GP50184@devbig004.ftw2.facebook.com> References: <20190124160009.GA12436@cmpxchg.org> <20190124170117.GS4087@dhcp22.suse.cz> <20190124182328.GA10820@cmpxchg.org> <20190125074824.GD3560@dhcp22.suse.cz> <20190125165152.GK50184@devbig004.ftw2.facebook.com> <20190125173713.GD20411@dhcp22.suse.cz> <20190125182808.GL50184@devbig004.ftw2.facebook.com> <20190128125151.GI18811@dhcp22.suse.cz> <20190128142816.GM50184@devbig004.ftw2.facebook.com> <20190128145210.GM18811@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190128145210.GM18811@dhcp22.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Mon, Jan 28, 2019 at 03:52:10PM +0100, Michal Hocko wrote: > > All .events files generate aggregated stateful notifications. For > > anyone to do anything, they'd have to remember the previous state to > > identify what actually happened. Being hierarchical, it'd of course > > need to walk down when an event triggers. > > And how do you do that in a raceless fashion? Hmm... I'm having trouble imagining why this would be a problem. How would it race? Thanks. -- tejun