From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751989AbdFZSz1 (ORCPT ); Mon, 26 Jun 2017 14:55:27 -0400 Received: from mga11.intel.com ([192.55.52.93]:39674 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751498AbdFZSyx (ORCPT ); Mon, 26 Jun 2017 14:54:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,397,1493708400"; d="scan'208";a="985411515" From: Vikas Shivappa To: x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de Cc: hpa@zytor.com, peterz@infradead.org, ravi.v.shankar@intel.com, vikas.shivappa@intel.com, tony.luck@intel.com, fenghua.yu@intel.com, andi.kleen@intel.com Subject: [PATCH 17/21] x86/intel_rdt/cqm: Add sched_in support Date: Mon, 26 Jun 2017 11:56:04 -0700 Message-Id: <1498503368-20173-18-git-send-email-vikas.shivappa@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1498503368-20173-1-git-send-email-vikas.shivappa@linux.intel.com> References: <1498503368-20173-1-git-send-email-vikas.shivappa@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org OS associates an RMID/CLOSid to a task by writing the per CPU IA32_PQR_ASSOC MSR when a task is scheduled in. The sched_in code will stay as no-op unless we are running on Intel SKU which supports either resource control or monitoring and we also enable them by mounting the resctrl fs. The per cpu CLOSid/RMID values are cached and the write is performed only when a task with a different CLOSid/RMID is scheduled in. Signed-off-by: Vikas Shivappa --- arch/x86/include/asm/intel_rdt_sched.h | 47 ++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/intel_rdt_sched.h b/arch/x86/include/asm/intel_rdt_sched.h index 4dee77b..7c823c4 100644 --- a/arch/x86/include/asm/intel_rdt_sched.h +++ b/arch/x86/include/asm/intel_rdt_sched.h @@ -27,27 +27,31 @@ struct intel_pqr_state { DECLARE_PER_CPU(struct intel_pqr_state, pqr_state); DECLARE_PER_CPU_READ_MOSTLY(int, cpu_closid); +DECLARE_PER_CPU_READ_MOSTLY(int, cpu_rmid); DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key); +DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); +DECLARE_STATIC_KEY_FALSE(rdt_enable_key); /* - * intel_rdt_sched_in() - Writes the task's CLOSid to IA32_PQR_MSR + * __intel_rdt_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR * * Following considerations are made so that this has minimal impact * on scheduler hot path: * - This will stay as no-op unless we are running on an Intel SKU - * which supports resource control and we enable by mounting the - * resctrl file system. - * - Caches the per cpu CLOSid values and does the MSR write only - * when a task with a different CLOSid is scheduled in. + * which supports resource control or monitoring and we enable by + * mounting the resctrl file system. + * - Caches the per cpu CLOSid/RMID values and does the MSR write only + * when a task with a different CLOSid/RMID is scheduled in. * * Must be called with preemption disabled. */ -static inline void intel_rdt_sched_in(void) +static void __intel_rdt_sched_in(void) { - if (static_branch_likely(&rdt_alloc_enable_key)) { - struct intel_pqr_state *state = this_cpu_ptr(&pqr_state); - int closid; + struct intel_pqr_state *state = this_cpu_ptr(&pqr_state); + u32 closid = 0; + u32 rmid = 0; + if (static_branch_likely(&rdt_alloc_enable_key)) { /* * If this task has a closid assigned, use it. * Else use the closid assigned to this cpu. @@ -55,14 +59,31 @@ static inline void intel_rdt_sched_in(void) closid = current->closid; if (closid == 0) closid = this_cpu_read(cpu_closid); + } + + if (static_branch_likely(&rdt_mon_enable_key)) { + /* + * If this task has a rmid assigned, use it. + * Else use the rmid assigned to this cpu. + */ + rmid = current->rmid; + if (rmid == 0) + rmid = this_cpu_read(cpu_rmid); + } - if (closid != state->closid) { - state->closid = closid; - wrmsr(IA32_PQR_ASSOC, state->rmid, closid); - } + if (closid != state->closid || rmid != state->rmid) { + state->closid = closid; + state->rmid = rmid; + wrmsr(IA32_PQR_ASSOC, rmid, closid); } } +static inline void intel_rdt_sched_in(void) +{ + if (static_branch_likely(&rdt_enable_key)) + __intel_rdt_sched_in(); +} + #else static inline void intel_rdt_sched_in(void) {} -- 1.9.1