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 4ADF6ECAAA3 for ; Fri, 26 Aug 2022 17:16:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D49896B0075; Fri, 26 Aug 2022 13:16:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CD1C6940008; Fri, 26 Aug 2022 13:16:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7290940007; Fri, 26 Aug 2022 13:16:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id A7A206B0075 for ; Fri, 26 Aug 2022 13:16:33 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 852301606F1 for ; Fri, 26 Aug 2022 17:16:33 +0000 (UTC) X-FDA: 79842397866.17.4C4A86B Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf16.hostedemail.com (Postfix) with ESMTP id 325D5180025 for ; Fri, 26 Aug 2022 17:16:32 +0000 (UTC) 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 1DF1761BF3; Fri, 26 Aug 2022 17:16:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04F61C433D7; Fri, 26 Aug 2022 17:16:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661534191; bh=iDINRuAQ4YmaJq22k2DCZ+hhEQstH3cgG8wNmEwf7RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=daNeke0IhQ/wVEd02y7AL28gqaIRqwNto6VvGKWd5c4ahO5ZFNwOT2REHKTpkC550 KR8okkektQbiFKq7NS/VmDQmDLpEF+Fz9c8vyTrbVppRif+qF0dcSUH4ZyMJJLV5CI wPmI0gOiQPtiWYeV2TEs0hacs8vNABhzIqOrnuTsgPtvGh2CEb862SW0+wXzG8qFT6 SbeIDmdl6Fr/NRuCHxp1RpXE0DoKHKETm0qj21GEl5IIyX8mo+gIr1JLXdNhwZ0HIF lNgffucmLb4JL5s08Q93Cn/JoLbXgqJmxr/tYXIGxLRqX101R9Xlblm9H1z9b6bifB kIGvWEhqEGe8g== From: SeongJae Park To: xiakaixu1987@gmail.com Cc: sj@kernel.org, akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kaixu Xia Subject: Re: [PATCH 2/2] mm/damon/vaddr: remove comparison between mm and last_mm when checking region accesses Date: Fri, 26 Aug 2022 17:16:29 +0000 Message-Id: <20220826171629.50210-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <1661502678-19336-3-git-send-email-kaixuxia@tencent.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=daNeke0I; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf16.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661534193; a=rsa-sha256; cv=none; b=4SAa4e6elUu2JugOzXAsfB0BEiOpAaksTNJtyVmXYdFx6+GX7rqtWaBMilAptyOYBgcaFb rIIvWQEp3qW2c2PYHac0R3LN41A7yMso9vcsnTjsrfcBmxPSruxu3E7MOGw5YyKzvccGMl /VuO3NoFAUCbR/eLa5dhb+N/edtdAhk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661534193; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0Q09jyCZuhxcaiAxPBmcEv5Zrw5gWtKLlahjZ9Iyukg=; b=AWvesoeirXvcFUeD2YWgvWXfTIbbCa5kFXz/34LrbWvguwuKtGMw1UkJ/SVxk2JtF49EML Qbl6PjnlZ3THZZHb9K8bE2JETF9hsvyaQddEG3gZhS/Q+ZsBBfbWGCe15f+GJJVzMB3wo/ qqrvul700X8DwhApWXFYtZfdNA0J4VQ= X-Rspam-User: X-Rspamd-Queue-Id: 325D5180025 Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=daNeke0I; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf16.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org X-Stat-Signature: fxygawap7z9ubogbc8t4ur4xr9by9j7d X-Rspamd-Server: rspam03 X-HE-Tag: 1661534192-948659 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: Hi Kaixu, On Fri, 26 Aug 2022 16:31:18 +0800 xiakaixu1987@gmail.com wrote: > From: Kaixu Xia > > The damon regions that belong to the same damon target have the same > 'struct mm_struct *mm', so it's unnecessary to compare the mm and last_mm > objects among the damon regions in one damon target when checking accesses. There could be multiple targets, and 'damon_va_check_accesses()' calls '__damon_va_check_accesses()' for all the targets. However, 'damon_va_check_accesses()' doesn't note if '__damon_va_check_accesses()' is called with a target that same to the target it was called with for the last time. Hence the check is necessary. If I'm missing something, please let me know. Thanks, SJ [...]