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 5E273C433FE for ; Tue, 22 Mar 2022 21:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236860AbiCVVuv (ORCPT ); Tue, 22 Mar 2022 17:50:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236923AbiCVVup (ORCPT ); Tue, 22 Mar 2022 17:50:45 -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 6A77F51E43 for ; Tue, 22 Mar 2022 14:49:17 -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 07A556149C for ; Tue, 22 Mar 2022 21:49:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BAA9C340EE; Tue, 22 Mar 2022 21:49:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985756; bh=ZPovejT+mS4ShXN/nfO853TOrgfFMjd8KIsrmY37H88=; h=Date:To:From:In-Reply-To:Subject:From; b=VQ+FPq88EYuoYlE4CD6Gb4EagG+YE9N176cXUfB1eWQrJJP+2z/Pk+JqnUqov6ReR nFIt7jrfF/WlWPA1hPlnITFGn8WxXhmrkAlOHGVuEX/xKsXCXfnDof9eS0CutGwUUr G5YEZswwJevnFuBv6345j6oMKgVjI4SC2PMdAmEg= Date: Tue, 22 Mar 2022 14:49:15 -0700 To: corbet@lwn.net, sj@kernel.org, akpm@linux-foundation.org, patches@lists.linux.dev, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 212/227] Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling Message-Id: <20220322214916.5BAA9C340EE@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: SeongJae Park Subject: Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling In DAMON's early development stage before it be merged in the mainline, it was first designed to work exclusively with Idle page tracking to avoid any interference between each other. Later, but still before be merged in the mainline, because Idle page tracking is fully under the control of sysadmins, we made the resolving of conflict as the responsibility of sysadmins. The document is not updated for the change, though. This commit updates the document for that. Link: https://lkml.kernel.org/r/20220222170100.17068-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton --- Documentation/vm/damon/design.rst | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/Documentation/vm/damon/design.rst~docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling +++ a/Documentation/vm/damon/design.rst @@ -84,9 +84,10 @@ table having a mapping to the address. and clear the bit(s) for next sampling target address and checks whether the bit(s) set again after one sampling period. This could disturb other kernel subsystems using the Accessed bits, namely Idle page tracking and the reclaim -logic. To avoid such disturbances, DAMON makes it mutually exclusive with Idle -page tracking and uses ``PG_idle`` and ``PG_young`` page flags to solve the -conflict with the reclaim logic, as Idle page tracking does. +logic. DAMON does nothing to avoid disturbing Idle page tracking, so handling +the interference is the responsibility of sysadmins. However, it solves the +conflict with the reclaim logic using ``PG_idle`` and ``PG_young`` page flags, +as Idle page tracking does. Address Space Independent Core Mechanisms _ From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 92A786465 for ; Tue, 22 Mar 2022 21:49:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BAA9C340EE; Tue, 22 Mar 2022 21:49:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985756; bh=ZPovejT+mS4ShXN/nfO853TOrgfFMjd8KIsrmY37H88=; h=Date:To:From:In-Reply-To:Subject:From; b=VQ+FPq88EYuoYlE4CD6Gb4EagG+YE9N176cXUfB1eWQrJJP+2z/Pk+JqnUqov6ReR nFIt7jrfF/WlWPA1hPlnITFGn8WxXhmrkAlOHGVuEX/xKsXCXfnDof9eS0CutGwUUr G5YEZswwJevnFuBv6345j6oMKgVjI4SC2PMdAmEg= Date: Tue, 22 Mar 2022 14:49:15 -0700 To: corbet@lwn.net,sj@kernel.org,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 212/227] Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling Message-Id: <20220322214916.5BAA9C340EE@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: SeongJae Park Subject: Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling In DAMON's early development stage before it be merged in the mainline, it was first designed to work exclusively with Idle page tracking to avoid any interference between each other. Later, but still before be merged in the mainline, because Idle page tracking is fully under the control of sysadmins, we made the resolving of conflict as the responsibility of sysadmins. The document is not updated for the change, though. This commit updates the document for that. Link: https://lkml.kernel.org/r/20220222170100.17068-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: Jonathan Corbet Signed-off-by: Andrew Morton --- Documentation/vm/damon/design.rst | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/Documentation/vm/damon/design.rst~docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling +++ a/Documentation/vm/damon/design.rst @@ -84,9 +84,10 @@ table having a mapping to the address. and clear the bit(s) for next sampling target address and checks whether the bit(s) set again after one sampling period. This could disturb other kernel subsystems using the Accessed bits, namely Idle page tracking and the reclaim -logic. To avoid such disturbances, DAMON makes it mutually exclusive with Idle -page tracking and uses ``PG_idle`` and ``PG_young`` page flags to solve the -conflict with the reclaim logic, as Idle page tracking does. +logic. DAMON does nothing to avoid disturbing Idle page tracking, so handling +the interference is the responsibility of sysadmins. However, it solves the +conflict with the reclaim logic using ``PG_idle`` and ``PG_young`` page flags, +as Idle page tracking does. Address Space Independent Core Mechanisms _