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 178541A294; Wed, 10 Sep 2025 04:00:26 +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=1757476827; cv=none; b=q28ytGJKm14xbaJMoMLCCoBPqaR0oozx0yrcbVdDBKA8Ng/ip86qSWq9HGto6Z4UmM+a/HOEK/O9w5fszDIhjQQuAUXRLwN7qVUACpxohLcXkCrMfDbesMHQ3ejDKdTKy3T6SAclZZn1OGd7sTtunOgWJ7kHhTlAcT333/5DX24= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757476827; c=relaxed/simple; bh=XVQm/ezzZOJcJYBzuueA7pTOiZ/IJc3OYpKjbETFs6w=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=mEamF/W8mGn1FeNGIHfH/iKouO61w9cZJEkYD6rXit47d2XkH2hqO0yMxHOGwggkDkFWkOHHNlabsJUZjL68p3ekzWA219Mg2rp5R3bZLYQQslDxpRGk2z++McHuvvdadjtSQmSh9iDjlw0N0SG5QlTWwGy8rlHOEaIGfZ5Y1fs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F51/FDg+; 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="F51/FDg+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7499EC4CEF0; Wed, 10 Sep 2025 04:00:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757476826; bh=XVQm/ezzZOJcJYBzuueA7pTOiZ/IJc3OYpKjbETFs6w=; h=From:To:Cc:Subject:Date:From; b=F51/FDg+uIp45MA5Pk5Ny+yXxiFF2Tw6bnhlvN7bwRcn5NL7QD/dvCntAL4pZcHQj Clada5Q//btVK1p816mXUNxx7ATviSMgRN39lP3smLyTH4wgC4yfMUzTMZmaA7OJ1v alD6d7lweRLonrmG+L1iywfQ19N21t9cGdBGFOxVaO5HCuloriUsVVS+JP/L1bMT2l Z+IFH4HcpbRSv6nxq3OiYXs2nCIcCUSBKyzKfxwa+3Ssv++h1ujaRdNTm1iJse/Vub jIJRjYCsMS7AwQGf00D4rVFvfJpGt3MT15zq/CZRlhm31UOkjtfbyz0pW/Gkie4Sah inWt/35FUa5tg== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , damon@lists.linux.dev, kernel-team@meta.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 0/2] mm/damon/stat: expose auto-tuned intervals and non-idle ages Date: Tue, 9 Sep 2025 21:00:20 -0700 Message-Id: <20250910040022.168223-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit DAMON_STAT is intentionally providing limited information for easy consumption. From production fleet level usages, below limitations are found, though. The aggregation interval of DAMON_STAT represents the granularity of the memory_idle_ms_percentiles. But it is auto-tuned and not exposed to users, so users cannot know the granularity. All memory regions of non-zero (positive) nr_accesses are treated as having zero idle time. A significant portion of production systems have such zero idle time. Hence breakdown of warm and hot data is impossible. To overcome the limitations, expose the auto-tuned aggregation interval with a new parameter named xxx and the age of non-zero nr_accesses regions as negative idle time, via the existing idle time percentiles parameter. SeongJae Park (2): mm/damon/stat: expose the current tuned aggregation interval mm/damon/stat: expose negative idle time mm/damon/stat.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) base-commit: adc22cc8eb821b7d8274403ad7bdafb411fcc9d7 -- 2.39.5