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=-9.9 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=no 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 B4E67C3F2D1 for ; Wed, 4 Mar 2020 20:45:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6E7FF207FD for ; Wed, 4 Mar 2020 20:45:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wHrZLvAt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E7FF207FD Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 171486B0003; Wed, 4 Mar 2020 15:45:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 121FC6B0005; Wed, 4 Mar 2020 15:45:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 038216B0007; Wed, 4 Mar 2020 15:45:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0066.hostedemail.com [216.40.44.66]) by kanga.kvack.org (Postfix) with ESMTP id DD1A86B0003 for ; Wed, 4 Mar 2020 15:45:30 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 7A716246A for ; Wed, 4 Mar 2020 20:45:30 +0000 (UTC) X-FDA: 76558860420.14.name31_6a47909842f3f X-HE-Tag: name31_6a47909842f3f X-Filterd-Recvd-Size: 4094 Received: from mail-pj1-f65.google.com (mail-pj1-f65.google.com [209.85.216.65]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Mar 2020 20:45:30 +0000 (UTC) Received: by mail-pj1-f65.google.com with SMTP id a16so1444274pju.3 for ; Wed, 04 Mar 2020 12:45:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=bSssoW6aFVtYbqfH2RQfHGPyl30tcb1D7T0IFzp6CiQ=; b=wHrZLvAte9VBOVY1o96UtBWoPp1ikUjEojHSDjOxtEbBQ7U3yONVGuEruSLMWYhwhI q+iSE8ArSoDUE5cxh/3eNyyBmYM8CDIjGHICFoQlFIunjSF8GlNWqHRlmwKcx8HXb631 kJcM5NIauzZDt17vhBzDcSmQCXDDNhoaG8DqO46SmgdZvPknArsV5a7KzIm0vb1DTDWt /sHKASxd4Xiez8aFydm0594os17orXKGBmD3tRimTGrK7Wo5ih1RTI2Cemg4rhTFRwjq FbjERSDJNnJcc0FAeNiWQj9p5XYyrdZPd2+J/NK/stuQL8Cs+32C1vM65GwMv2hr6uZV 8f0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=bSssoW6aFVtYbqfH2RQfHGPyl30tcb1D7T0IFzp6CiQ=; b=gREtOKQgXd0cgMXcd0RV59/lqf8cZ9nXwHRuwHsIwk8lXaOvnP8xeHM6529dA35Jvx ChpOBXFhpN390qoghd5F8RA8naTKUZKTH4CELHN12+b4zt2KPT+mWpDzBEEFYPo7rOjV PLEiI6YoEX9nxA07sok/DEnlXTLBrAzO60/Qdf0mx/FEr23G7IV3hdwik48zrfwbDYUF JWHwVA1kx2LFrfxq9GMwqhx38TdTFWZtW8nMyBviOBRnfjp9VzqIOMVef/IkylbDQzIx UfIGUqG2HLGCsfb9SAN3K5wpJ277Gl2oqhrzfTITmE/n+6fJ5J519L5T51F4bOrdMoZn vusA== X-Gm-Message-State: ANhLgQ2ctaWkbCr0pZ05rL29J9lIgsX7ynN98Z072pHdTlFeShDRA45S fbNKI5Uv2gTMYebZJ7ACDm/rCw== X-Google-Smtp-Source: ADFU+vvbCvj9+Tk7UslBowQCU89mQmq5dKR8f8wr3FcdkxVmhP+ZrVXcL8z26ro0YUT/N8AmGvg6vg== X-Received: by 2002:a17:90b:19cf:: with SMTP id nm15mr1503230pjb.69.1583354728838; Wed, 04 Mar 2020 12:45:28 -0800 (PST) Received: from [2620:15c:17:3:3a5:23a7:5e32:4598] ([2620:15c:17:3:3a5:23a7:5e32:4598]) by smtp.gmail.com with ESMTPSA id b9sm528776pgi.75.2020.03.04.12.45.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 12:45:28 -0800 (PST) Date: Wed, 4 Mar 2020 12:45:27 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: David Hildenbrand cc: "Huang, Ying" , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen , Mel Gorman , Vlastimil Babka , Zi Yan , Michal Hocko , Peter Zijlstra , Minchan Kim , Johannes Weiner , Hugh Dickins Subject: Re: [PATCH -V2] mm: Add PageLayzyFree() helper functions for MADV_FREE In-Reply-To: Message-ID: References: <20200304081732.563536-1-ying.huang@intel.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: On Wed, 4 Mar 2020, David Hildenbrand wrote: > In general, I don't think this patch really improves the situation ... > it's only a handful of places where this change slightly makes the code > easier to understand. And there, only slightly ... I'd prefer better > comments instead (e.g., in PageAnon()), documenting what it means for a > anon page to either have PageSwapBacked() set or not. > Agreed, I think any changes to clarify what PageSwapBacked means when it's set and when it's clear for PageAnon should be in the form of a comment, likely in page-flags.h. That's currently lacking for lazy free pages.