From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D1CDE368D45 for ; Sat, 5 Sep 2026 16:52:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788627150; cv=none; b=CQavA5yA+wWuATvuql3C5GZv7v8UrdW/M+EEGYiT6YRuFmGIlBfRdxr5YZajL08I0YngDBVWe3a+jOdZjiCS0Mi5YthZeAbInq/JymqH0zo9+QPU5of5gHqvuyS87AA68KCa6lTt7etaY9HTGEmTNbhU3kFfYkc/I+aXCE4RYIU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788627150; c=relaxed/simple; bh=uK5ERlxda1rAEDQRVOrVJT9lk1PtbRdW2voD2aCX2B8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TEj0FTgyxLoiSPadGvn3OrVFAhaIWgo4MRCdk6jnbDozIF49hFxwap9segoErTQlcrF6Z77+BjpfYqgnlLF9vViDUrEnQJoggL10S6+2EpoPvvkrc2sLhZ3jWJ7IcGoVNs99+ktY/z04ZGwNnSuSV9jhkzO640bPNU5JjIOK6Jc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Df3yij/L; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Df3yij/L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B4BA1F00A3A; Sat, 5 Sep 2026 16:52:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788627148; bh=1C2eg3cenbcfacI4YbTnX7lIlYM2EwRcdmw9F9GajEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Df3yij/LQmtO49IV0phC66lZPqsI5fIa4iyHaeVONOqZJHjPaV/Hx+XWVCq0kEiaI 8PQ4dO+PYALtEIOIFwqaxttCI7Tg76K9BQwXGp8q2vn+8v4ucL3P7l6xALE3bjFoq6 aoOM+z8GGnLnnCI4snSXjhguHkhz8i4WcD9BVh60+dLkKSWW+ARh8a+CD+syhW2ZVp ez/7jAQQnquCslXJ9gkp46WQeYawra8CMbUaov5kijGWLDfEFzz2uPDqE+vKKs1evy A8VwNUBwXaw4EgDZ71SBHrDUO4V25lgNfYoDHp2GYlyTbHDgcy8kpP8wut9bMpP28K cJrPKpmbQum2A== From: SJ Park To: SJ Park Cc: damon@lists.linux.dev, Ravi Jonnalagadda , Akinobu Mita , Andrew Paniakin Subject: Re: Roadmap for extending DAMON beyond pte-accessed bit Date: Sat, 5 Sep 2026 09:52:20 -0700 Message-ID: <20260905165221.83994-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260711004808.32620-1-sj@kernel.org> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Fri, 10 Jul 2026 17:48:08 -0700 SJ Park wrote: > On Wed, 24 Jun 2026 07:56:14 -0700 SeongJae Park wrote: > > > On Mon, 25 May 2026 15:52:08 -0700 SeongJae Park wrote: > > > > > Hello, > > > > > > > > > TLDR: Let's extend DAMON for data attributes monitoring, andd then further > > > extend that for multiple access check primitives including page faults, perf > > > memory-access events and optimized AMD IBS-like h/w feature drivers. > > [...] > > > Roadmap > > > ======= > > > > > > Assuming you agree to use the data attributes monitoring interface, I suggest > > > us to do the work in below roadmap. > > > > > > Milestone 1: PTE Accessed bit as one of the data attributes > > > ----------------------------------------------------------- > > > > > > I will work on stabilizing and further extending the data attributes interface > > > and internal framework to be able to support PTE Accessed bit. This may take > > > no small amount of efforts, but hopefully doable by the end of this year. > > > > Let me share more detailed plan for this milestone. Nothing is set on the > > stone. Everything can be changed on the road. > > > > The overall goal is, making attributes monitoring be able to do everything we > > are doing now with PTE Accessed-bit based monitoring. It is needed because we > > want to do everythin we can do now with the PMU/page fault-based DAMON. Also > > it is needed because we will need to deprecate nr_accesses in long term without > > breaking users. For this, below changes will be made. [...] > > 3. Extend attrs for PTE Accessed bit check > > > > Further, we will extend DAMON attributes monitoring to handle PTE Accessed bit > > check. We will extend it to let users configure probing preparation > > operations. The first operation to support will be the PTE Accessed bit > > clearing operation. Together, we will introduce new DAMON probe filter that > > checks the PTE Accessed bit. Using those, users will be able to do the > > PTE Accessed bit based access monitoring in attrs-only monitoring mode. > > I have a hacking level prototype for this in damon/next tree. I will take more > time for stabilizing it. I'm aiming to make this be merged into 7.4-rc1. The patch series [1] for this is now merged into mm.git. Hopefully it will be merged into 7.4-rc1 as planned. Note that the series is supporting only paddr. I'm working on extending it for vaddr. Actually there were user requests for this. A working prototype is in damon/next. > > > > > 4. Extend attrs for DAMOS > > > > Finally, we will extend DAMOS to be able to run with probe_hits. That is, it > > will be extended to let users configure the DAMOS target access pattern and do > > its quota-prioritization based on the probe_hits. > > > > After the four major changes are made, the attributes only mode DAMON can do > > everything current DAAMON is doing, without nr_accesses. We will then move on > > to the milestone 2 of this project, and start a long term nr_accesses > > deprecation. > > > > I hope all changes to be landed by 7.5-rc1. I'm now working on this. Actually there were user requests for this. A working prototype implementation of an essential change is in damon/next. Hopefully that will be landed by 7.5-rc1. Some additional works for full DAMOS support are expected, and those may be done after 7.5-rc1. > > So I believe we are still on the track :) > > [1] moving sum: https://lore.kernel.org/20260703170605.94472-1-sj@kernel.org > [2] attrs-only: https://lore.kerrnel.org/20260710134651.18084-1-sj@kernel.org > [3] attrs-only enqueue notice: > https://lore.kernel.org/20260710202349.2F2DA1F000E9@smtp.kernel.org/ [1] https://lore.kernel.org/20260901132506.99243-1-sj@kernel.org Thanks, SJ [...]