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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 80585E8B386 for ; Wed, 4 Feb 2026 00:29:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 68FD16B0005; Tue, 3 Feb 2026 19:29:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 63E186B0088; Tue, 3 Feb 2026 19:29:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 53CFD6B0089; Tue, 3 Feb 2026 19:29:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 3F84D6B0005 for ; Tue, 3 Feb 2026 19:29:11 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 4A9B2C2527 for ; Wed, 4 Feb 2026 00:29:10 +0000 (UTC) X-FDA: 84404889660.30.78153F9 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf14.hostedemail.com (Postfix) with ESMTP id B4B47100008 for ; Wed, 4 Feb 2026 00:29:08 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=IU8Q6VfB; spf=pass (imf14.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1770164948; 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:dkim-signature; bh=MCC0bYHCM8u1pPn0ANwYquSmtcOEsUk77yy9AQP6rJg=; b=YZBcemiIyZbqnwh8ZLaQdBUV7Rt3Hl4o9zGHGtxsez7fu1AZ91TkkY4yG2lUMKZvHpicgd aYVE6zQdzjCRX5iO/YiVMb86xY/QGBJaUguSv20vXB7YXkk9lIMVNAUPunPdwryr20h46o XhUqxfkLZmRML5hEXsaQV2bj7vy8mOI= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=IU8Q6VfB; spf=pass (imf14.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770164948; a=rsa-sha256; cv=none; b=dJc4IU3xBNXwMwfnu4ttyn1NgK/l8R9eILAXsRO+pSKByXPUK0x0VgWu0gFRQN38Gh1OsM 5bf+RPsAAOh96OZkGKhx1kCwaUWmPxd9+AJxLin8CUgKJ7PCqy3IBPGDZj14erH7lV06BZ BxeV68EDmJ/jJmCBBTdQ1JqfNPcHuzw= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id E2AE76012A; Wed, 4 Feb 2026 00:29:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6442BC2BC86; Wed, 4 Feb 2026 00:29:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770164947; bh=qXE3g6jBKd0Y66pW7cPox46N88wlCWyAaIJYLCmu0uQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IU8Q6VfBQMpLFZ67aNKfIJIqzkP9TvOhTNtI59fwSZSXV6YqPxKwrWdmpHBv1dwSg 0VX5XZAN2rHTJ0fg32vC10Tsf1IkW0dCshjF1o730hypxasYnFn7LYpV9dECkI+2ji ID09hCOwY7aUJJA2j5qoXyaGuhMo+MWELNg3FAYKxAf5zf6fdPhQ/ZaqY5ZxiM/zKn G7+fEneH8mR2fRK4JYehWvbxOT9ag3t7+WbSuwXO99Hwcpf/mqviuc1hWzmw4/IHbz 7aGM2i79izcajfS5FS0mr/49sCoZxV1zCtmF82l5Sy08MXY7wRjrxOR27yq85g47gW mtTmJPdG6tunw== From: SeongJae Park To: Ravi Jonnalagadda Cc: SeongJae Park , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, akpm@linux-foundation.org, corbet@lwn.net, bijan311@gmail.com, ajayjoshi@micron.com, honggyu.kim@sk.com, yunjeong.mun@sk.com Subject: Re: [RFC PATCH v2 0/3] mm/damon: Introduce node_target_mem_bp Quota Goal Metric Date: Tue, 3 Feb 2026 16:28:58 -0800 Message-ID: <20260204002900.49291-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: B4B47100008 X-Rspamd-Server: rspam07 X-Stat-Signature: upqhmya4pmofsyx49fdqe934t8bfypgf X-HE-Tag: 1770164948-282296 X-HE-Meta: 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 dY7zImmy QCeK6+WBeDfCVqtKOHDqT/JzbfgcHWqmas5x/Ug+Rn4nkvM7zzfAurGwd7c5YKZvT0Yp+QOsQUP/hH1YKRY1szs142sLUQ2FQSu3eSIinRUPILwRFY8h0nKYPajgCxFe5aAoiKcIGDKrA/tldMpvqd2Pd70Bohm6VFDbV6PAi53XHK22oFhmXgjRwoyRZB3egYDj4KnXZgpW7MQl4+q7yVQpW4kvEUVZd7LAibpKLsSIUiJMcBXDR4HdlKiS1fMN2MGg8mBpM9cKSmra5uDoRGa3Vb+CIYapE0pVc0mOQxToQlwz0ZmUa22U2WvwWlsbgaYGuBlVJDghusxU+B6Xhn19hYxOcsdWB7NH1Fw8nCGv8d2UYl0bCLA+BWzqeXz5fxakBjqmGmioJ2L7z+bAZeatizIiGtc/4ERgR 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: List-Subscribe: List-Unsubscribe: On Tue, 3 Feb 2026 11:48:06 -0800 Ravi Jonnalagadda wrote: > On Sat, Jan 31, 2026 at 11:54 AM SeongJae Park wrote: > > > > On Thu, 29 Jan 2026 17:48:06 -0800 SeongJae Park wrote: > > > > > On Thu, 29 Jan 2026 13:58:11 -0800 Ravi Jonnalagadda wrote: > > > > > > > This series introduces a new DAMON quota goal metric, `node_target_mem_bp`, > > > > designed for controlling memory migration in heterogeneous memory systems > > > > (e.g., DRAM and CXL memory tiering). > > > > > > > > v1: https://lore.kernel.org/linux-mm/20260123045733.6954-1-ravis.opensrc@gmail.com/T/#u > > [...] > > > Context 0: monitors node 0, migrate_hot -> node 1 > > > goal: node_ineligible_mem_bp, nid=0, target=4000 > > > > > > Context 1: monitors node 1, migrate_hot -> node 0 > > > goal: node_target_mem_bp, nid=0, target=6000 > > > > In offline, Ravi enlightened me that using a single context with two schemes > > instead of the above two contexts setup can be more efficienct and useful. I > > agree that. It will be able to only single kdamond, and there could be more > > flexible use cases that can use the whole-memory access pattern. > > > > That is, we can use single context with the two schemes, but adding a core > > layer DAMOS filters for applying the schemes to only memory of node 0 and node > > 1, respectively. Similar for memory tiering use cases. > > > > But I was recommending the multi contexts approach to people because the > > current implementation of DAMOS is not efficient when both quota and core layer > > filters are used. I was actually working on making it improved, and just > > posted an RFC patch series [1]. After the patches are merged, hopefully the > > single context approach will be useful and effcient enough for varying use > > cases including the memory tiering. > > > > [1] https://lore.kernel.org/20260131194145.66286-1-sj@kernel.org > > > Thanks for providing the DAMOS_FILTER patch update SJ. > > For v3, I plan to introduce two complementary metrics: > DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP > and DAMOS_QUOTA_NODE_INELIGIBLE_MEM_BP. > > This will support the following approaches for hot memory migration: > 1. Single context with two schemes using both metrics. > (along with DAMOS_FILTER_TYPE_ADDR) > 2. Two DAMON contexts each using > DAMOS_QUOTA_NODE_INELIGIBLE_MEM_BP. Sounds good! > > Will provide more details on the implementation and usage in the v3 series. Looking forward to it! Thanks, SJ [...]