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 CCA3AC00140 for ; Thu, 18 Aug 2022 17:17:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245539AbiHRRRO (ORCPT ); Thu, 18 Aug 2022 13:17:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345330AbiHRRQ6 (ORCPT ); Thu, 18 Aug 2022 13:16:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E7352610C for ; Thu, 18 Aug 2022 10:11:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B777761645 for ; Thu, 18 Aug 2022 17:11:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2644C433D7; Thu, 18 Aug 2022 17:11:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660842708; bh=Mc/teE1LL9vULZCSDU4ycYT9u3eYQsCxpUOtyauN4pA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AWZJlPCUjq7p7vu1Bz1r9kJMchqJkGqlekx/lzPT6Oj4nq7WfVIZWD8OhWHR2XkVX ZnKbvC1td2JxmqeAdI92wUok2KK0c+EGdwAkUYukMT0fkHzjx++xPTyA00oZfxDQsU oObrS3/4Qeb8iKzTN3NRGKr2Hqg0xImh2Zp0BOkmRMrE/lzEOtzH2nV3907a3fZRpf jXcDflt8dDHueJRaAPrBJ+5KerzThkqKlYnEssdtOjzTBPv+jNv7wM7iov/uUCc/Hl agnxm4gTMg5MrPk4VELdphBGUPn8P0x5dNqePLwdV5MNnFfetscJh8KZYrUCkUs/FV Cf5Qi8CnwkXOA== From: SeongJae Park To: Xin Hao Cc: sj@kernel.org, akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 1/2] mm/damon/lru_sort: Move target memory region check to head of func Date: Thu, 18 Aug 2022 17:11:45 +0000 Message-Id: <20220818171145.51607-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220818105732.34492-2-xhao@linux.alibaba.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. So I'd argue this patch seems not really needed, sorry. Thanks, SJ [...]