From nobody Sun Feb 8 16:31:47 2026 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (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 4302435770D for ; Wed, 29 Oct 2025 16:21:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761754911; cv=none; b=dCUZRVOr1jZwtEBL4Lp1ATE/eazfpeNd21+2ibI9dRKeyb2i7sGmQz2O3in8+jNtHJQYW1xr8mAQqIwCRc9lrBwV2lW5LbekaRQ0nyWU4dG5e7kIN9EQ5PtnVkSvVDz9D96IaYVODc067yedBheLauIu9S3RCw9wEWNk77EKz8U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761754911; c=relaxed/simple; bh=JgzCMbemHDEiivLyDauttzfjz0gFspBynkBemT2+69k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=izjw9gVKX1oWUV3xM+AAUx2go9igVNCsS2GQh/LhjwfQTvEY0yYo6VelJsRyjFQu3xGuygvv+HaUKaeE1vuhRuzRtAwwiAA2B2g2jz/7wkzJdFm69+epuzmVR38wQ6ej0e6idynUVA5NKGUVAMKjWtfi0NBjZLZctUgfAkMH8ug= 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=AarcC+9B; arc=none smtp.client-ip=198.175.65.12 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="AarcC+9B" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1761754909; x=1793290909; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JgzCMbemHDEiivLyDauttzfjz0gFspBynkBemT2+69k=; b=AarcC+9B0XmJHlqcXY53HNN1tWdbf2FFwjiabb3G/7lcg8FiCRTc2Weq XobrCOC7Cok/YzaZVJF/PSZ96ELpcOpdAbVd/jr/kdBMhEwPj34+bDzHS h1csIRhNPWwPiB2wUnOPuVH/PWoXHCyD7pCCjt+NgKH0RdCOdJI5KZNqK cHO7EwtWr9o/AvG9ilMIPgdQhrqKgoQY0A8q4v5wCB/GExVdH4xV7AwAA Yr+i0/e5JazCooQ2GMdbxslmiIjlLDygc2yXB5j7vfJGAynw2/lwYkY7E FIxQWG5HPLQrEry20Iz0SfnxJ4TPTR0/x3qHYuqgDMtE+gEVIUfscljUG Q==; X-CSE-ConnectionGUID: Udxz3i6eQ0ijU0J7j++YSg== X-CSE-MsgGUID: cm+8e3GeSIKDrN2LXfKR3g== X-IronPort-AV: E=McAfee;i="6800,10657,11597"; a="75331050" X-IronPort-AV: E=Sophos;i="6.19,264,1754982000"; d="scan'208";a="75331050" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2025 09:21:36 -0700 X-CSE-ConnectionGUID: S47MFZktTGOIg0cL+9Xcow== X-CSE-MsgGUID: KIL3ymaXSyKvrcEAw/gs7A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,264,1754982000"; d="scan'208";a="184901419" Received: from mgerlach-mobl1.amr.corp.intel.com (HELO agluck-desk3.home.arpa) ([10.124.223.146]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2025 09:21:36 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin , Chen Yu Cc: x86@kernel.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [PATCH v13 30/32] fs/resctrl: Provide interface to create architecture specific debugfs area Date: Wed, 29 Oct 2025 09:21:13 -0700 Message-ID: <20251029162118.40604-31-tony.luck@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251029162118.40604-1-tony.luck@intel.com> References: <20251029162118.40604-1-tony.luck@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" All files below /sys/fs/resctrl are considered user ABI. This leaves no place for architectures to provide additional interfaces. Add resctrl_debugfs_mon_info_arch_mkdir() which creates a directory in the debugfs file system for a monitoring resource. Naming follows the layout of the main resctrl hierarchy: /sys/kernel/debug/resctrl/info/{resource}_MON/{arch} The {arch} last level directory name matches the output of the user level "uname -m" command. Architecture code may use this directory for debug information, or for minor tuning of features. It must not be used for basic feature enabling as debugfs may not be configured/mounted on production systems. Suggested-by: Reinette Chatre Signed-off-by: Tony Luck Reviewed-by: Reinette Chatre --- include/linux/resctrl.h | 10 ++++++++++ fs/resctrl/rdtgroup.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index a2bf335052d6..3d176f4d6b6e 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -678,6 +678,16 @@ void resctrl_arch_reset_cntr(struct rdt_resource *r, s= truct rdt_l3_mon_domain *d extern unsigned int resctrl_rmid_realloc_threshold; extern unsigned int resctrl_rmid_realloc_limit; =20 +/** + * resctrl_debugfs_mon_info_arch_mkdir() - Create a debugfs info directory. + * Removed by resctrl_exit(). + * @r: Resource (must be mon_capable). + * + * Return: NULL if resource is not monitoring capable, + * dentry pointer on success, or ERR_PTR(-ERROR) on failure. + */ +struct dentry *resctrl_debugfs_mon_info_arch_mkdir(struct rdt_resource *r); + int resctrl_init(void); void resctrl_exit(void); =20 diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index 17f5b986f210..0257c9938455 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -24,6 +24,7 @@ #include #include #include +#include =20 #include =20 @@ -75,6 +76,8 @@ static void rdtgroup_destroy_root(void); =20 struct dentry *debugfs_resctrl; =20 +static struct dentry *debugfs_resctrl_info; + /* * Memory bandwidth monitoring event to use for the default CTRL_MON group * and each new CTRL_MON group created by the user. Only relevant when @@ -4531,6 +4534,31 @@ int resctrl_init(void) return ret; } =20 +/* + * Create /sys/kernel/debug/resctrl/info/{r->name}_MON/{arch} directory + * by request for architecture to use for debugging or minor tuning. + * Basic functionality of features must not be controlled by files + * added to this directory as debugfs may not be configured/mounted + * on production systems. + */ +struct dentry *resctrl_debugfs_mon_info_arch_mkdir(struct rdt_resource *r) +{ + struct dentry *moninfodir; + char name[32]; + + if (!r->mon_capable) + return NULL; + + if (!debugfs_resctrl_info) + debugfs_resctrl_info =3D debugfs_create_dir("info", debugfs_resctrl); + + sprintf(name, "%s_MON", r->name); + + moninfodir =3D debugfs_create_dir(name, debugfs_resctrl_info); + + return debugfs_create_dir(utsname()->machine, moninfodir); +} + static bool resctrl_online_domains_exist(void) { struct rdt_resource *r; @@ -4582,6 +4610,7 @@ void resctrl_exit(void) =20 debugfs_remove_recursive(debugfs_resctrl); debugfs_resctrl =3D NULL; + debugfs_resctrl_info =3D NULL; unregister_filesystem(&rdt_fs_type); =20 /* --=20 2.51.0