From nobody Wed Apr 1 11:13:53 2026 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 301C738425B for ; Mon, 30 Mar 2026 21:43:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774907016; cv=none; b=lhf0Xb1rZFPbw88QoJ58kBv8E8bACPztdn6p7Je7mPo1OKDqubowF26VCfKvw6HuBMd+JKM5d8Phz5xyeKYvifeW+dCTXUJxltvQMtkTJHPQK8J1Ta5Zyv3chZTDlkBD9ighFjS/PGv3CaTolmw/usEdMkxidVJCoLJKf+RD+kw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774907016; c=relaxed/simple; bh=ZmrW/lnrmraTGrG222FCq68z97lMPh4tb6hecweEEP4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pGrcr6X39te1RDb1hN/ZreWkzicg8aomlUztzBEd7/1+MnMteztCIbgT7LEWjILXKit+qRVHL5ekOtHaBkXwOrXACajPptwNv64lDNUzHmEf43TO8+yn8KVkTpVkHZ7MWI1SyHPpv9/rXt8rWbEhOE9Ou+ALE0m20AOZfkh7ctk= 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=iKj71Ina; arc=none smtp.client-ip=198.175.65.14 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="iKj71Ina" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1774907014; x=1806443014; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ZmrW/lnrmraTGrG222FCq68z97lMPh4tb6hecweEEP4=; b=iKj71InaqbFdEomivbFQZ7mFKzYVoGg2BVgQuPKsfWg4qITBEfQLCrG0 EaDHobrsszxXKii7oRZWgeEO3lPSII37Lo0oeue0SQmxEJVHhhkF9YEYb Wy/zr0HHXuIzSQcD5mG0McgPBrXnegYrV43qXqts3QLLuAQN98lKcS+uf x1wbQv8y4HZ5o1KBikanP3Yg8b6m5+1SagsOSiix9m9qtEG7VocopkIc2 9X++R0IpJNphWhyjSMb+wQCKwwub9dI6MdZeSMvTC/BjAv/8Vde6WXmmG CIVE+2aft9L60p8E4V0FE1LKD9zyu0ojm2iidnTmBnuqat2OEM909cde6 Q==; X-CSE-ConnectionGUID: /vFAJGwFTn6vOzX+WGNiZg== X-CSE-MsgGUID: YM2HND86Q12iSZpDenNpsQ== X-IronPort-AV: E=McAfee;i="6800,10657,11744"; a="79772152" X-IronPort-AV: E=Sophos;i="6.23,150,1770624000"; d="scan'208";a="79772152" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2026 14:43:33 -0700 X-CSE-ConnectionGUID: GWFOHd8UQT2V+mDjRssSYw== X-CSE-MsgGUID: PaSeuy4iRaKBwwCGYBT+Aw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,150,1770624000"; d="scan'208";a="225185945" Received: from spandruv-desk1.amr.corp.intel.com (HELO agluck-desk3.home.arpa) ([10.124.222.186]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2026 14:43:33 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Maciej Wieczor-Retman , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin , Chen Yu , David E Box , x86@kernel.org Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev, Tony Luck Subject: [PATCH v4 4/7] fs,x86/resctrl: Add architecture hooks for every mount/unmount Date: Mon, 30 Mar 2026 14:43:19 -0700 Message-ID: <20260330214322.96686-5-tony.luck@intel.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260330214322.96686-1-tony.luck@intel.com> References: <20260330214322.96686-1-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" Add hooks for every mount/unmount of the resctrl file system so that architecture code can allocate on mount and free on unmount. Signed-off-by: Tony Luck --- Note this patch disables enumeration of AET monitor events because the new mount/unmount hooks do not call intel_aet_get_events() (which is not ready for the change from "just on first mount" to "called on every mount"). That is resolved in the next patch. include/linux/resctrl.h | 12 +++++-- arch/x86/kernel/cpu/resctrl/internal.h | 8 +++-- arch/x86/kernel/cpu/resctrl/core.c | 14 +++++++- arch/x86/kernel/cpu/resctrl/intel_aet.c | 13 ++++++++ fs/resctrl/rdtgroup.c | 43 ++++++++++++++++++------- 5 files changed, 74 insertions(+), 16 deletions(-) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index b312aaf76974..489c7d4ae3e9 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -518,11 +518,19 @@ void resctrl_online_cpu(unsigned int cpu); void resctrl_offline_cpu(unsigned int cpu); =20 /* - * Architecture hook called at beginning of first file system mount attemp= t. - * No locks are held. + * Architecture hooks for resctrl mount/unmount. + * Each is called with resctrl_mount_lock held. */ + +/* Called at beginning of each file system mount attempt. */ void resctrl_arch_pre_mount(void); =20 +/* Called to report success/failure of mount. */ +void resctrl_arch_mount_result(int ret); + +/* Called to report unmount. */ +void resctrl_arch_unmount(void); + /** * resctrl_arch_rmid_read() - Read the eventid counter corresponding to rm= id * for this resource and domain. diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/r= esctrl/internal.h index e3cfa0c10e92..6f322818a9e6 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -234,14 +234,18 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource *= r); void resctrl_arch_mbm_cntr_assign_set_one(struct rdt_resource *r); =20 #ifdef CONFIG_X86_CPU_RESCTRL_INTEL_AET -bool intel_aet_get_events(void); +bool intel_aet_pre_mount(void); +void intel_aet_mount_result(int ret); +void intel_aet_unmount(void); void __exit intel_aet_exit(void); int intel_aet_read_event(int domid, u32 rmid, void *arch_priv, u64 *val); void intel_aet_mon_domain_setup(int cpu, int id, struct rdt_resource *r, struct list_head *add_pos); bool intel_handle_aet_option(bool force_off, char *tok); #else -static inline bool intel_aet_get_events(void) { return false; } +static inline bool intel_aet_pre_mount(void) { return false; } +static inline void intel_aet_mount_result(int ret) { } +static inline void intel_aet_unmount(void) { } static inline void __exit intel_aet_exit(void) { } static inline int intel_aet_read_event(int domid, u32 rmid, void *arch_pri= v, u64 *val) { diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resct= rl/core.c index 7667cf7c4e94..162eca2cfcdb 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -769,8 +769,10 @@ void resctrl_arch_pre_mount(void) struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_PERF_PKG].r_re= sctrl; int cpu; =20 - if (!intel_aet_get_events()) + if (!intel_aet_pre_mount()) { + r->mon_capable =3D false; return; + } =20 /* * Late discovery of telemetry events means the domains for the @@ -786,6 +788,16 @@ void resctrl_arch_pre_mount(void) cpus_read_unlock(); } =20 +void resctrl_arch_mount_result(int ret) +{ + intel_aet_mount_result(ret); +} + +void resctrl_arch_unmount(void) +{ + intel_aet_unmount(); +} + enum { RDT_FLAG_CMT, RDT_FLAG_MBM_TOTAL, diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/= resctrl/intel_aet.c index 015627401ed2..743a1894fe9a 100644 --- a/arch/x86/kernel/cpu/resctrl/intel_aet.c +++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c @@ -335,6 +335,19 @@ void __exit intel_aet_exit(void) } } =20 +bool intel_aet_pre_mount(void) +{ + return false; // Temporary stub +} + +void intel_aet_mount_result(int ret) +{ +} + +void intel_aet_unmount(void) +{ +} + #define DATA_VALID BIT_ULL(63) #define DATA_BITS GENMASK_ULL(62, 0) =20 diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index 5da305bd36c9..2ce11ae2d2cd 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -18,7 +18,6 @@ #include #include #include -#include #include #include #include @@ -30,6 +29,9 @@ =20 #include "internal.h" =20 +/* Mutex protecting mount/unmount operations */ +static DEFINE_MUTEX(resctrl_mount_lock); + /* Mutex to protect rdtgroup access. */ DEFINE_MUTEX(rdtgroup_mutex); =20 @@ -2788,17 +2790,8 @@ static int rdt_get_tree(struct fs_context *fc) struct rdt_resource *r; int ret; =20 - DO_ONCE_SLEEPABLE(resctrl_arch_pre_mount); - cpus_read_lock(); mutex_lock(&rdtgroup_mutex); - /* - * resctrl file system can only be mounted once. - */ - if (resctrl_mounted) { - ret =3D -EBUSY; - goto out; - } =20 ret =3D setup_rmid_lru_list(); if (ret) @@ -2900,6 +2893,30 @@ static int rdt_get_tree(struct fs_context *fc) return ret; } =20 +static int rdt_get_tree_wrapper(struct fs_context *fc) +{ + int ret; + + mutex_lock(&resctrl_mount_lock); + + /* + * resctrl file system can only be mounted once. + */ + if (resctrl_mounted) { + mutex_unlock(&resctrl_mount_lock); + return -EBUSY; + } + + resctrl_arch_pre_mount(); + + ret =3D rdt_get_tree(fc); + + resctrl_arch_mount_result(ret); + mutex_unlock(&resctrl_mount_lock); + + return ret; +} + enum rdt_param { Opt_cdp, Opt_cdpl2, @@ -2959,7 +2976,7 @@ static void rdt_fs_context_free(struct fs_context *fc) static const struct fs_context_operations rdt_fs_context_ops =3D { .free =3D rdt_fs_context_free, .parse_param =3D rdt_parse_param, - .get_tree =3D rdt_get_tree, + .get_tree =3D rdt_get_tree_wrapper, }; =20 static int rdt_init_fs_context(struct fs_context *fc) @@ -3169,6 +3186,7 @@ static void rdt_kill_sb(struct super_block *sb) { struct rdt_resource *r; =20 + mutex_lock(&resctrl_mount_lock); cpus_read_lock(); mutex_lock(&rdtgroup_mutex); =20 @@ -3187,6 +3205,9 @@ static void rdt_kill_sb(struct super_block *sb) kernfs_kill_sb(sb); mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); + + resctrl_arch_unmount(); + mutex_unlock(&resctrl_mount_lock); } =20 static struct file_system_type rdt_fs_type =3D { --=20 2.53.0