From nobody Fri Dec 19 19:01:32 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 1C6A032AAC9 for ; Thu, 4 Dec 2025 20:54:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764881686; cv=none; b=DoW3AZFXemejTU01oiMe5P62mIoRe2p3z0GprNIS3kjt7/LBnICpqdFqzIKifc6e1OpLfWzCUNZVI2lZ5x5w0d8/9an9DPOdhDTMCf5A7pvQBTV3yXPIZ5GHuI5MDQy7zan52smdgyDVI2ZH0Ql8KexzKoGaivneQHCVZ2lH1So= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764881686; c=relaxed/simple; bh=a6GqSiYes3g1hfurapo7TsD5x6nKUzU6tpAj8OUBXbc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iDR0KFeYDAB3rwyMHwmVwF3LFB6vSiSFrRvCoTo1JwHCybLf9fcAfwrYMlvKVNlbr1a2XsUt25CPQb8E4OvsUxp5sO0cVsjDKapZaOSmVHBXYa4BTSJVPGLZMI/b4nOal6OHXYnhvJs16n1vfRALjvaSdoS7Y9XqsUfn6DIN+Ac= 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=e1KfSz44; arc=none smtp.client-ip=192.198.163.13 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="e1KfSz44" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1764881684; x=1796417684; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=a6GqSiYes3g1hfurapo7TsD5x6nKUzU6tpAj8OUBXbc=; b=e1KfSz44NeN/NC/g/CC3JBjYwl4K5XYm4PwT06v4khfQFVi0BhZZAx47 Xg/dLy2rdLQ/EykQMepQz0ufizEJRV+TNgGtC0YvxIxOT0EzaJW6HsACq R9fb/jZsj2twQdCBo12fiksCWr52D5SssSpcfT6NBq2ogHKlG1OsEtN3J ZT2PZKnubkJT5TxEp8nTBrSSKUJcASFUl350hMqurEArZgdbFF+jB4tm9 VIpvHfKnmrlDMSGiuLEx2svbTk730aELHjmPg4oEQ3Hw0U84Rlaz7WmSy Al3IEaXs0cNvJVLlV+CSYpaUGNsC9GN1mh1jCWpRoxPUmCEdPgC6ybKU9 w==; X-CSE-ConnectionGUID: WfpxeyiBRrenMKwsE4vj+A== X-CSE-MsgGUID: OYBErPJGSQO5uRhgDrnMNQ== X-IronPort-AV: E=McAfee;i="6800,10657,11632"; a="69511100" X-IronPort-AV: E=Sophos;i="6.20,250,1758610800"; d="scan'208";a="69511100" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2025 12:54:33 -0800 X-CSE-ConnectionGUID: ol0jKBxLQTqK7on07XF9AA== X-CSE-MsgGUID: yKbjNv6RSeuUfqPBjIUkEA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,250,1758610800"; d="scan'208";a="225752894" Received: from mgerlach-mobl1.amr.corp.intel.com (HELO agluck-desk3.intel.com) ([10.124.220.165]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2025 12:54:33 -0800 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 v15 30/32] fs/resctrl: Provide interface to create architecture specific debugfs area Date: Thu, 4 Dec 2025 12:54:00 -0800 Message-ID: <20251204205404.12763-31-tony.luck@intel.com> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251204205404.12763-1-tony.luck@intel.com> References: <20251204205404.12763-1-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 debug= fs 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 8623e450619a..b862a9dd785b 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -702,6 +702,16 @@ bool resctrl_arch_get_io_alloc_enabled(struct rdt_reso= urce *r); 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 d49ffc56ea61..d13291d71adf 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 @@ -4599,6 +4602,31 @@ 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; @@ -4650,6 +4678,7 @@ 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 2.51.1