From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (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 B6CCC2ED846 for ; Fri, 20 Mar 2026 22:03:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774044235; cv=none; b=SqhtH7DArMYVe5AdwfIS2kO1SSgkN9JjkBEU4857XEiio8C2QXJb6G93hGnZD/cKKc+7zifdNjIdDqMlqKB3gMjc+T4MGdgcTB+SNIsDDhO7B4FJecVBWL3vkeRgeVcgYRdxPjV5//VJ7kWJf2OytdyE7xLbS/yueG7Sde6bFdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774044235; c=relaxed/simple; bh=+e8kpRBt7Bz02RMHeF2deNwekfepP0rgAolx8zRW8aQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=ZNTfvHQr7NZup5xjX6Kwoo/KoRK74Y+Ogbz0/L31/q/YtAn36WQ9OtSBF4j3jsjxPzsqND7reLxsdrnOwbqY1pIWvxMc4snx42fIBF+lpHeuVysQFh0gq4q0OXTkXLN8vt67EKvp9yo4mlrF9OHnGfJO/X/ebEgf33+tBORZZrA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=K9xJV4CN; arc=none smtp.client-ip=198.175.65.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="K9xJV4CN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1774044233; x=1805580233; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=+e8kpRBt7Bz02RMHeF2deNwekfepP0rgAolx8zRW8aQ=; b=K9xJV4CNjm5UufRWo1rOGUkPH+CDEDnFMsIU8sSEnRRZMSQAMgpDqgXr mYb8MDyKo0ykaUJ3/a6Dc/CHi0THG4UDKbLpdckduCtlT5yif0HgvHeuC vTRWBVKt2oItuJw3G4xzYe9nv85aNIV8ras3lAv3MN0rQKbsyZFvRCAU4 WGpnQRpGqBnwzyuLIDRxQyJt/9fYJ979KQy1kzWWF8tT5BiQjn1J9D9/j ULJk02JPgKt4H9CK1nEg7+TG/l1r/A7MhTV3SeZG/EMiVPgbDxHdLDyOr DUZK1xkfngvEaNA3vSAYkb6/dY346M88Xpd02XPhRT1+4PX2AhUwV317F A==; X-CSE-ConnectionGUID: 6qavOzfrQ2SHSqpf5JUzYQ== X-CSE-MsgGUID: p1eq15i2QvmqYhAFNHT1dA== X-IronPort-AV: E=McAfee;i="6800,10657,11735"; a="97758324" X-IronPort-AV: E=Sophos;i="6.23,132,1770624000"; d="scan'208";a="97758324" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2026 15:03:53 -0700 X-CSE-ConnectionGUID: uVBQhpjKQrmOf3RTyGAIRA== X-CSE-MsgGUID: lZT/e7olQFSD7F9j6DHogw== X-ExtLoop1: 1 Received: from rchatre-desk1.jf.intel.com ([10.165.154.99]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2026 15:03:52 -0700 From: Reinette Chatre To: tony.luck@intel.com, james.morse@arm.com, Dave.Martin@arm.com, babu.moger@amd.com, bp@alien8.de, tglx@linutronix.de, dave.hansen@linux.intel.com Cc: x86@kernel.org, hpa@zytor.com, ben.horgan@arm.com, fustini@kernel.org, fenghuay@nvidia.com, peternewman@google.com, linux-kernel@vger.kernel.org, patches@lists.linux.dev, reinette.chatre@intel.com Subject: [PATCH v2 00/14] x86,fs/resctrl: Improve resctrl quality and consistency Date: Fri, 20 Mar 2026 15:03:10 -0700 Message-ID: X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Changes since v1: - v1: https://lore.kernel.org/lkml/cover.1772476561.git.reinette.chatre@intel.com/ - To simplify tracking, include patch to MAINTAINERS submitted separately: https://lore.kernel.org/lkml/4274c478922c01f9ceebc805acf991f10a95519f.1771442788.git.reinette.chatre@intel.com/ - Follow recent upstream changes to add reference to tip tree handbook in MAINTAINERS entry. - Use new pattern in resctrl to enable looping over all entries of an enum while making adding new enum entries more clear all while avoiding warnings when compiling with -Wswitch. (Ben) - Add another last_cmd_status enhancement that appends "[truncated]" to output of info/last_cmd_status if the backing buffer overflowed. - Please see patch changelogs for details of changes. - Add tags. Hi Everybody, This is a collection of resctrl cleanups assembled together for convenience and simpler tracking. I'd be happy to split them up if it makes review and/or handling easier. Summary of changes: - Let resctrl pass stricter checks from various tools to provide a cleaner baseline with the goal to promote healthier contributions: - ./tools/docs/kernel-doc -Wall -v - Build with W=12 - ./scripts/coccicheck - Static checkers - Use accurate and consistent type for all uses of resource ID. - In the unlikely scenario that resctrl picked a wrong CPU to read an event from, pass the error through to user space instead of claiming to succeed and returning a (wrong) result. - Since inception of last_cmd_status feature there have been mismatches between resctrl file operation failures and the contents of info/last_cmd_status. This pattern keeps propagating with each new resctrl feature. Establish a new baseline with a new pattern that ensures info/last_cmd_status contains an accurate failure description that matches the most recent resctrl file operation failure. One potential open: There remains an inconsistency between resctrl file operations that do/can _not_ fail and the contents of info/last_cmd_status. If a resctrl file operation fails and an informational error is printed to last_cmd_status then a subsequent reading of a resctrl file (specifically most of the files found in info/) may succeed while info/last_cmd_status may or may not return the error from previous failure. Ensuring last_cmd_status is reset on every read carries the cost of taking rdtgroup_mutex on several more user space initiated paths and thus increase contention on rdtgroup_mutex. I opted to not make this change and instead focus this work on ensuring that last_cmd_status is accurate whenever there is a failure during any resctrl file operation. Please let me know if you have opinions in this regard. Any feedback is appreciated. Regards, Reinette Reinette Chatre (14): MAINTAINERS: Update resctrl entry fs/resctrl: Add missing return value descriptions fs/resctrl: Avoid "may be used uninitialized" warning fs/resctrl: Use correct format specifier for printing error pointers x86/resctrl: Protect against bad shift fs/resctrl: Change pattern used to track number of entries in enum fs/resctrl: Use accurate type for rdt_resource::rid fs/resctrl: Pass error reading event through to user space fs/resctrl: Add last_cmd_status support for writes to max_threshold_occupancy fs/resctrl: Use accurate and symmetric exit flows fs/resctrl: Use stricter checks on input to cpus/cpus_list file fs/resctrl: Change last_cmd_status custom during input parsing fs/resctrl: Communicate resource group deleted error via last_cmd_status fs/resctrl: Inform user space when status buffer overflowed MAINTAINERS | 2 + arch/x86/kernel/cpu/resctrl/core.c | 4 +- fs/resctrl/ctrlmondata.c | 70 +++++++++------ fs/resctrl/monitor.c | 80 ++++++++++------- fs/resctrl/pseudo_lock.c | 2 +- fs/resctrl/rdtgroup.c | 137 ++++++++++++++++++----------- include/linux/resctrl.h | 11 +-- 7 files changed, 188 insertions(+), 118 deletions(-) -- 2.50.1