From nobody Fri Oct 3 14:45:02 2025 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 D222A2505AA for ; Fri, 29 Aug 2025 19:34:00 +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=1756496043; cv=none; b=IXeOIZ0d2i1UFLhPvZBA5Rql81GNnwUpWlzFfIwb7+IICV9acmRHIxXuHBKruqH3PwqxAJ4Au7RqgkyXeVXAzGJTg8FBFkYOEm3QoILEd/dDbRmykPB4u99rliZegNGcxHgAHIqehq4CvjgWIX/86yNG4mkHI6RX3p82VzzvLQQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756496043; c=relaxed/simple; bh=AZpQLMSAWucS5TY1G5esDx+Ncmg6K63CI2arPWnJGlQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G2TuhZhiVolXusuIhhxCrnCxdO8/hvqwv6+gpmFxJHfNJoysBRX6Edl6uo9i5T6cxPM75ZFIZbNpTekqwV2P11cKc3+YU8FSclrUvoTfeS0tEFJTkEe8VA3Cu8+oTs/uo9A50/5YTy2jjKwXPL5y896JjGOtalk7g2cDwx5Qd+Q= 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=HKSyM+j7; 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="HKSyM+j7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1756496040; x=1788032040; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=AZpQLMSAWucS5TY1G5esDx+Ncmg6K63CI2arPWnJGlQ=; b=HKSyM+j7/Phw6TGyyJIYGR+Y3KL/6qBEDDa068wQda9yc80c2pROPMCW 7o5lPkfGmvXqPU/SFqHk0Oa4U7/t1DU64lfgkFwq6pe9fAPP/MBoLx+MM /ACGyPS6yjO/g/hHDtyplgF/Bk7x9ac+f8Vr3dJdMqn68hGV97+acMxKV xeiDEtQNasE9JZaWHOEI8wYkVDYo8sLd3q/bBQPi2g8PG0P4mfjNh4DY8 NzxB6ajMbfn5+L8Nq/WugCJgkONfPGw10vvDIlhH5TslxtY7TGng0EHVQ IyRIgOqj3rojkTQfWzDA6jFbsj+Jlpfj/wxt5ZjiUvmFgeZKfVaY1pyOg w==; X-CSE-ConnectionGUID: pBZLu/yoRWK6k5i2VRBRBA== X-CSE-MsgGUID: XTMcBvj0RamK9rAcLtHDFw== X-IronPort-AV: E=McAfee;i="6800,10657,11531"; a="62625241" X-IronPort-AV: E=Sophos;i="6.17,312,1747724400"; d="scan'208";a="62625241" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Aug 2025 12:33:54 -0700 X-CSE-ConnectionGUID: 4eFOJgHMRoC7er0KFGb1YA== X-CSE-MsgGUID: JsbjE3D2RVS5TYQy3MzCyA== X-ExtLoop1: 1 Received: from ldmartin-desk2.corp.intel.com (HELO agluck-desk3.intel.com) ([10.124.220.202]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Aug 2025 12:33:54 -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 v9 13/31] x86,fs/resctrl: Handle events that can be read from any CPU Date: Fri, 29 Aug 2025 12:33:25 -0700 Message-ID: <20250829193346.31565-14-tony.luck@intel.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250829193346.31565-1-tony.luck@intel.com> References: <20250829193346.31565-1-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" resctrl assumes that monitor events can only be read from a CPU in the cpumask_t set of each domain. This is true for x86 events accessed with an MSR interface, but may not be true for other access methods such as MMIO. Add a flag to struct mon_evt to indicate if the event can be read on any CPU. Architecture uses resctrl_enable_mon_event() to enable an event and set the flag appropriately. Bypass all the smp_call*() code for events that can be read on any CPU and call mon_event_count() directly from mon_event_read(). Add a test for events that can be read from any domain to skip checks in __mon_event_count() that the read is being done from a CPU in the correct domain or cache scope. Signed-off-by: Tony Luck --- include/linux/resctrl.h | 2 +- fs/resctrl/internal.h | 2 ++ arch/x86/kernel/cpu/resctrl/core.c | 6 ++-- fs/resctrl/ctrlmondata.c | 7 +++- fs/resctrl/monitor.c | 53 ++++++++++++++++++++++-------- 5 files changed, 51 insertions(+), 19 deletions(-) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 5788e1970d8c..17a21f193a3d 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -379,7 +379,7 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); u32 resctrl_arch_system_num_rmid_idx(void); int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); =20 -void resctrl_enable_mon_event(enum resctrl_event_id eventid); +void resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu); =20 bool resctrl_is_mon_event_enabled(enum resctrl_event_id eventid); =20 diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index b2a236b373c0..1f8a7cd5065b 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -57,6 +57,7 @@ static inline struct rdt_fs_context *rdt_fc2context(struc= t fs_context *fc) * @rid: resource id for this event * @name: name of the event * @configurable: true if the event is configurable + * @any_cpu: true if the event can be read from any CPU * @enabled: true if the event is enabled */ struct mon_evt { @@ -64,6 +65,7 @@ struct mon_evt { enum resctrl_res_level rid; char *name; bool configurable; + bool any_cpu; bool enabled; }; =20 diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resct= rl/core.c index b4f3fa4ec0d6..4961792af7f6 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -888,15 +888,15 @@ static __init bool get_rdt_mon_resources(void) bool ret =3D false; =20 if (rdt_cpu_has(X86_FEATURE_CQM_OCCUP_LLC)) { - resctrl_enable_mon_event(QOS_L3_OCCUP_EVENT_ID); + resctrl_enable_mon_event(QOS_L3_OCCUP_EVENT_ID, false); ret =3D true; } if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) { - resctrl_enable_mon_event(QOS_L3_MBM_TOTAL_EVENT_ID); + resctrl_enable_mon_event(QOS_L3_MBM_TOTAL_EVENT_ID, false); ret =3D true; } if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) { - resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID); + resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID, false); ret =3D true; } =20 diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index a99903ac5d27..2e65fddc3408 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -569,6 +569,11 @@ void mon_event_read(struct rmid_read *rr, struct rdt_r= esource *r, return; } =20 + if (evt->any_cpu) { + mon_event_count(rr); + goto out_ctx_free; + } + cpu =3D cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU); =20 /* @@ -581,7 +586,7 @@ void mon_event_read(struct rmid_read *rr, struct rdt_re= source *r, smp_call_function_any(cpumask, mon_event_count, rr, 1); else smp_call_on_cpu(cpu, smp_mon_event_count, rr, false); - +out_ctx_free: resctrl_arch_mon_ctx_free(r, evt->evtid, rr->arch_mon_ctx); } =20 diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index 81c3fb6a95b6..7332e65b0e01 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -356,15 +356,47 @@ static struct mbm_state *get_mbm_state(struct rdt_l3_= mon_domain *d, u32 closid, return state ? &state[idx] : NULL; } =20 +/* + * Called from preemptible context via a direct call of mon_event_count() = for + * events that can be read on any CPU. + * Called from preemptible but non-migratable process context (mon_event_c= ount() + * via smp_call_on_cpu()) OR non-preemptible context (mon_event_count() via + * smp_call_function_any()) for events that need to be read on a specific = CPU. + */ +static bool cpu_on_correct_domain(struct rmid_read *rr) +{ + struct cacheinfo *ci; + int cpu; + + /* Any CPU is OK for this event */ + if (rr->evt->any_cpu) + return true; + + cpu =3D smp_processor_id(); + + /* Single domain. Must be on a CPU in that domain. */ + if (rr->hdr) + return cpumask_test_cpu(cpu, &rr->hdr->cpu_mask); + + if (WARN_ON_ONCE(rr->r->rid !=3D RDT_RESOURCE_L3)) + return false; + + /* Summing domains that share a cache, must be on a CPU for that cache. */ + ci =3D get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + + return ci && ci->id =3D=3D rr->ci_id; +} + static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) { - int cpu =3D smp_processor_id(); struct rdt_l3_mon_domain *d; - struct cacheinfo *ci; struct mbm_state *m; int err, ret; u64 tval =3D 0; =20 + if (!cpu_on_correct_domain(rr)) + return -EINVAL; + if (rr->r->rid =3D=3D RDT_RESOURCE_L3 && rr->first) { if (!domain_header_is_valid(rr->hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3= )) return -EINVAL; @@ -377,9 +409,7 @@ static int __mon_event_count(u32 closid, u32 rmid, stru= ct rmid_read *rr) } =20 if (rr->hdr) { - /* Reading a single domain, must be on a CPU in that domain. */ - if (!cpumask_test_cpu(cpu, &rr->hdr->cpu_mask)) - return -EINVAL; + /* Single domain. */ rr->err =3D resctrl_arch_rmid_read(rr->r, rr->hdr, closid, rmid, rr->evt->evtid, &tval, rr->arch_mon_ctx); if (rr->err) @@ -390,15 +420,9 @@ static int __mon_event_count(u32 closid, u32 rmid, str= uct rmid_read *rr) return 0; } =20 - if (WARN_ON_ONCE(rr->r->rid !=3D RDT_RESOURCE_L3)) - return -EINVAL; - - /* Summing domains that share a cache, must be on a CPU for that cache. */ - ci =3D get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); - if (!ci || ci->id !=3D rr->ci_id) - return -EINVAL; - /* + * Sum across multiple domains. + * * Legacy files must report the sum of an event across all * domains that share the same L3 cache instance. * Report success if a read from any domain succeeds, -EINVAL @@ -877,7 +901,7 @@ struct mon_evt mon_event_all[QOS_NUM_EVENTS] =3D { }, }; =20 -void resctrl_enable_mon_event(enum resctrl_event_id eventid) +void resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu) { if (WARN_ON_ONCE(eventid < QOS_FIRST_EVENT || eventid >=3D QOS_NUM_EVENTS= )) return; @@ -886,6 +910,7 @@ void resctrl_enable_mon_event(enum resctrl_event_id eve= ntid) return; } =20 + mon_event_all[eventid].any_cpu =3D any_cpu; mon_event_all[eventid].enabled =3D true; } =20 --=20 2.50.1