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 8EA0A225760 for ; Thu, 6 Feb 2025 06:46:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738824388; cv=none; b=Q7Xf6VvAJj2FoqbenslFgJAzM1oyq5ihCepXMS6GDHjxGpn8kv8QtsOAMoANd4m4sAyKXSTINg1nLn+EZjl0DUbUn+9MQM4gf275CpkVKYetHpJj5po+uy1qhg7fHJBwn7XrXyEQmgJJZwiog3yly2MaNhLua9zJ/VH77o1BTUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738824388; c=relaxed/simple; bh=L/04Y76RLArXwdFii0mJtBTfcSdeQFU6jkHVLh9O17I=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=K8LkE4yQ0QsmdViNrqW5rZvMtSo32W89jdtgDYg8ghkcBBkVKDhLaqDnBnPy98fHsuqExnlW+TaM8gXeMhtb0DdmD4TVAzik+KrFYmE3YYEewJnZzQrQNVbYDzqDH87/8HDIPouCGK9d6UlqyEVBxSMAxJqDYmhQ7x4lq8ozPNE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CoE5a86r; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CoE5a86r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD725C4CEE5; Thu, 6 Feb 2025 06:46:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738824388; bh=L/04Y76RLArXwdFii0mJtBTfcSdeQFU6jkHVLh9O17I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CoE5a86ris0IpWocXajhAtzTjF7wF76YDX55jHiMlo14Mjc/i3UBb3864/TVtlzOi 81Kl0BzNU7RrcHX5bhm53cYxkcc/T2hLaVlprbofXwWJ4Zz5YISrU9mlSHOuEN+2wf Pa/1UhWaxAmMW0cZbVvTvfAzTaV9iawAxSAsuebOB8OpmBXVSJw2xrYF5Ht2DrrcXQ Mw2xQu5W1Elzoxqg9/AublBW1yH6BqMF4FxyctC9a50tkGjfjpFxvuyHroCffZEP2H 5Jq2etxnWlfhy4Z3yBjSLcnC29KHo9Yh2kCERYNxS0MzaanDQTXfuV5qbi5A6hB4dH j6ejlkS29g4NA== From: SeongJae Park To: Johannes Weiner Cc: SeongJae Park , Bharata B Rao , Jonathan Cameron , Raghavendra K T , linux-mm@kvack.org, akpm@linux-foundation.org, lsf-pc@lists.linux-foundation.org, gourry@gourry.net, nehagholkar@meta.com, abhishekd@meta.com, ying.huang@linux.alibaba.com, nphamcs@gmail.com, feng.tang@intel.com, kbusch@meta.com, Hasan.Maruf@amd.com, david@redhat.com, willy@infradead.org, k.shutemov@gmail.com, mgorman@techsingularity.net, vbabka@suse.cz, hughd@google.com, rientjes@google.com, shy828301@gmail.com, liam.howlett@oracle.com, peterz@infradead.org, mingo@redhat.com, nadav.amit@gmail.com, shivankg@amd.com, ziy@nvidia.com, jhubbard@nvidia.com, AneeshKumar.KizhakeVeetil@arm.com, linux-kernel@vger.kernel.org, jon.grimm@amd.com, santosh.shukla@amd.com, Michael.Day@amd.com, riel@surriel.com, weixugc@google.com, leesuyeon0506@gmail.com, honggyu.kim@sk.com, leillc@google.com, kmanaouil.dev@gmail.com, rppt@kernel.org, dave.hansen@intel.com Subject: Re: [LSF/MM/BPF TOPIC] Unifying sources of page temperature information - what info is actually wanted? Date: Wed, 5 Feb 2025 22:46:24 -0800 Message-Id: <20250206064624.3225-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250205160529.GB1183495@cmpxchg.org> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 5 Feb 2025 11:05:29 -0500 Johannes Weiner wrote: > On Wed, Feb 05, 2025 at 11:54:05AM +0530, Bharata B Rao wrote: > > On 31-Jan-25 6:39 PM, Jonathan Cameron wrote: > > > On Fri, 31 Jan 2025 12:28:03 +0000 > > > Jonathan Cameron wrote: [...] > > Here is a compilation of available temperature sources and how the > > hot/access data is consumed by different subsystems: > > This is super useful, thanks for collecting this. Indeed. Thank you Bharata! [...] > For the following table, it might be useful to add *when* the source > produces this information. Sampling frequency is a likely challenge: > consumers have different requirements, and overhead should be limited > to the minimum required to serve enabled consumers. +1 > > Here is an (incomplete) attempt - sorry about the long lines: > > > And here is an attempt to compile how different subsystems > > use the above data: > > ============================================================== > > Source Subsystem Consumption Activation/Frequency [...] > > ============================================================== > > PTE A bit via DAMON LRU activation, Continuous sampling (configurable)? > > rmap walk hot page promotion, (I believe SJ is looking into > > demotion etc auto-tuning this). You're right. I'm working on auto-tuning of the sampling/aggregation intervals of DAMON based on its tuning guide theory[1]. Hopefully I will be able to post an RFC patch series within a couple of weeks. > > ============================================================== > > Platform hints NUMAB NUMAB=1 Locality based > > (AMD IBS) balancing and > > NUMAB=2 hot page > > promotion > > ============================================================== > > Device hints NUMAB NUMAB=2 hot page > > promotion > > ============================================================== > > The last two are listed as possibilities. I'm also trying to extend DAMON to use PROT_NONE faults and AMD IBS like access check sources. Hopefully I will share more details of the plan and experiment results for the PROT_NONE faults extension by LSFMMBPF. [1] https://lore.kernel.org/20241202175459.2005526-1-sj@kernel.org Thanks, SJ [...]