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 67EDBECAAA6 for ; Fri, 26 Aug 2022 17:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344776AbiHZRQl (ORCPT ); Fri, 26 Aug 2022 13:16:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344654AbiHZRQe (ORCPT ); Fri, 26 Aug 2022 13:16:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DDAFB6D6A for ; Fri, 26 Aug 2022 10:16:34 -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 ams.source.kernel.org (Postfix) with ESMTPS id CF7E5B8320B for ; 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 [...]