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 C1BCEC00140 for ; Fri, 19 Aug 2022 02:12:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 017448D0003; Thu, 18 Aug 2022 22:12:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F0AEF8D0001; Thu, 18 Aug 2022 22:12:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DD23B8D0003; Thu, 18 Aug 2022 22:12:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id CE1FA8D0001 for ; Thu, 18 Aug 2022 22:12:41 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 9E0AA8016B for ; Fri, 19 Aug 2022 02:12:41 +0000 (UTC) X-FDA: 79814718522.26.810A317 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by imf07.hostedemail.com (Postfix) with ESMTP id 2C72540007 for ; Fri, 19 Aug 2022 02:12:38 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=xhao@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0VMdxGnC_1660875154; Received: from 30.240.99.21(mailfrom:xhao@linux.alibaba.com fp:SMTPD_---0VMdxGnC_1660875154) by smtp.aliyun-inc.com; Fri, 19 Aug 2022 10:12:35 +0800 Message-ID: <5c1c4b01-5ada-5c25-7181-a6f6c2c1f6ed@linux.alibaba.com> Date: Fri, 19 Aug 2022 10:12:34 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.1.0 Subject: Re: [PATCH V2 1/2] mm/damon/lru_sort: Move target memory region check to head of func To: SeongJae Park Cc: akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220818171145.51607-1-sj@kernel.org> From: haoxin In-Reply-To: <20220818171145.51607-1-sj@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660875160; a=rsa-sha256; cv=none; b=LHLknhoDOVnS6yCRfsJ9mMAz0mWocFBLZurPyc4B8WmW5G45L3SO3oab274vOW0w2OYosA a6ZXOUfs4KkaEWN9FPd1vzr0ravfoNXyxKCIkKjqZchJbLEChvmfeD7iqTb8q+g1B/xYKe LsLekUUP2YNQ579yPlUWoy5UOzTGIM4= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf07.hostedemail.com: domain of xhao@linux.alibaba.com designates 115.124.30.42 as permitted sender) smtp.mailfrom=xhao@linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660875160; 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; bh=V9n5LEUKlEJmvULdbPe0YY3xvCjJyLLujpw8VjtKrRM=; b=Ua0EVUcjVXyQIHzsXTErPOW/mKbTs91vgtYatohoD4QBUTmHaAchfwwMS09Jgn39ru3Xa2 JdhlMZBqjf15ISdfPtqgKTSxPPxkwOgW0atKnJ9YBDGvoeMvc4CYtTa2XZeMG+Ld6AbsJy FF5C5rbwv4mnyncKtFO0XYdF3rski/o= X-Stat-Signature: inrtb6g75fkdwps9y7c59wbx4jbe5bms X-Rspamd-Queue-Id: 2C72540007 X-Rspam-User: Authentication-Results: imf07.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf07.hostedemail.com: domain of xhao@linux.alibaba.com designates 115.124.30.42 as permitted sender) smtp.mailfrom=xhao@linux.alibaba.com X-Rspamd-Server: rspam11 X-HE-Tag: 1660875158-692110 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000018, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 在 2022/8/19 上午1:11, SeongJae Park 写道: > Hi Xin, > > > On Thu, 18 Aug 2022 18:57:31 +0800 Xin Hao wrote: > >> In damon_lru_sort_apply_parameters(), if "monitor_region_start" >> and "monitor_region_end" is not a valid physical address range, >> There no need to run the remainder codes in it. > The function, 'damon_lru_sort_apply_parameters()', checks validity of > parameters and construct the DAMON context one by one. For example, > 'damon_set_attrs()' returns an error if the parameters are invalid. So the > intended flow is, > > 1. check DAMON attributes parameters, > 2. apply DAMON attributes parameters, > 3. check scheme parameters, > 4. apply scheme parameters, > 5. check target region parameters, and > 6. apply target region parameters. > > Therefore what this patch does is making the target regions validity check to > be done earlier than validity checks of other parameters. There is no special > reason to check the region earlier than others. Also, this change makes the > flow of the function a little bit weird in my humble opinion, as the flow will > be > > 1. check target region parameters, > 2. check DAMON attributes parameters, > 3. apply DAMON attributes parameters, > 4. check scheme parameters, > 5. apply scheme parameters, and > 6. apply target region parameters. Ok, understand what you mean,   my fix looks ugly,  buy any apply above are not not necessary if one of them checks failed, why not check all fisrt and then apply them, like this: 1. check target region parameters, 2. check DAMON attributes parameters, 3. check scheme parameters, > > So I'd argue this patch seems not really needed, sorry. > > > Thanks, > SJ > > [...]