From patchwork Tue Feb 7 05:10:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Neri X-Patchwork-Id: 651630 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1886CC636D4 for ; Tue, 7 Feb 2023 05:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230172AbjBGFCB (ORCPT ); Tue, 7 Feb 2023 00:02:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230132AbjBGFBv (ORCPT ); Tue, 7 Feb 2023 00:01:51 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 795FC2B084; Mon, 6 Feb 2023 21:01:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675746103; x=1707282103; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=Ks6Wx9Pqszz2YvypOx73VVPt8pwQu0X0WqROcgHGPFg=; b=WZdoyckUVTPTLZ2SvcnaawYxkYhotga/TCp5v4N7a2+bLqWFEwZmIjlk WoWar9WG52JEq7WxCX/2bNAesLGgDxBYbocBFWpoy4y/xMiu/MEq/PjWe cCO0WmtY9GowklBREZ399+wQ2MVjzrTqQLKmN4XWXX9PU2CLnV5OREUN0 VhPmsYet5dPMJFBVEslZ1wfq4kFG+XPwEXk3JqvukrC+rDHvUQC7PWE2+ rF/PVCsHvI4lRJUXluceKGroS4y0UpdI3OIGzuEvyggnP+Z/DxSRFoVw/ kNEmureFao+KWih2O8kBXEhAeQICNolkr+1CWB/9lGWPUC+zJeNXsVZ/x w==; X-IronPort-AV: E=McAfee;i="6500,9779,10613"; a="415625749" X-IronPort-AV: E=Sophos;i="5.97,278,1669104000"; d="scan'208";a="415625749" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2023 21:01:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10613"; a="668657693" X-IronPort-AV: E=Sophos;i="5.97,278,1669104000"; d="scan'208";a="668657693" Received: from ranerica-svr.sc.intel.com ([172.25.110.23]) by fmsmga007.fm.intel.com with ESMTP; 06 Feb 2023 21:01:40 -0800 From: Ricardo Neri To: "Peter Zijlstra (Intel)" , Juri Lelli , Vincent Guittot Cc: Ricardo Neri , "Ravi V. Shankar" , Ben Segall , Daniel Bristot de Oliveira , Dietmar Eggemann , Len Brown , Mel Gorman , "Rafael J. Wysocki" , Srinivas Pandruvada , Steven Rostedt , Tim Chen , Valentin Schneider , Lukasz Luba , Ionela Voinescu , x86@kernel.org, "Joel Fernandes (Google)" , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Ricardo Neri , "Tim C . Chen" Subject: [PATCH v3 02/24] sched: Add interfaces for IPC classes Date: Mon, 6 Feb 2023 21:10:43 -0800 Message-Id: <20230207051105.11575-3-ricardo.neri-calderon@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230207051105.11575-1-ricardo.neri-calderon@linux.intel.com> References: <20230207051105.11575-1-ricardo.neri-calderon@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Add the interfaces that architectures shall implement to convey the data to support IPC classes. arch_update_ipcc() updates the IPC classification of the current task as given by hardware. arch_get_ipcc_score() provides a performance score for a given IPC class when placed on a specific CPU. Higher scores indicate higher performance. When a driver or equivalent enablement code has configured the necessary hardware to support IPC classes, it should call sched_enable_ipc_classes() to notify the scheduler that it can start using IPC classes data. The number of classes and the score of each class of task are determined by hardware. Cc: Ben Segall Cc: Daniel Bristot de Oliveira Cc: Dietmar Eggemann Cc: Ionela Voinescu Cc: Joel Fernandes (Google) Cc: Len Brown Cc: Lukasz Luba Cc: Mel Gorman Cc: Rafael J. Wysocki Cc: Srinivas Pandruvada Cc: Steven Rostedt Cc: Tim C. Chen Cc: Valentin Schneider Cc: x86@kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ricardo Neri --- Changes since v2: * Clarified the properties of the IPC score: abstract, and linear. It can normalized when needed. (Ionela) * Selected a better default IPC score. (Ionela) * Removed arch_has_ipc_classes(). It is not suitable for hardware that is not ready to support IPC classes after boot. (Lukasz) * Added a new sched_enable_ipc_classes() interface that drivers or enablement code can call when ready to support IPC classes. (Lukasz) Changes since v1: * Shortened the names of the IPCC interfaces (PeterZ): sched_task_classes_enabled >> sched_ipcc_enabled arch_has_task_classes >> arch_has_ipc_classes arch_update_task_class >> arch_update_ipcc arch_get_task_class_score >> arch_get_ipcc_score * Removed smt_siblings_idle argument from arch_update_ipcc(). (PeterZ) --- include/linux/sched/topology.h | 6 ++++ kernel/sched/sched.h | 66 ++++++++++++++++++++++++++++++++++ kernel/sched/topology.c | 9 +++++ 3 files changed, 81 insertions(+) diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 816df6cc444e..5b084d3c9ad1 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -280,4 +280,10 @@ static inline int task_node(const struct task_struct *p) return cpu_to_node(task_cpu(p)); } +#ifdef CONFIG_IPC_CLASSES +extern void sched_enable_ipc_classes(void); +#else +static inline void sched_enable_ipc_classes(void) { } +#endif + #endif /* _LINUX_SCHED_TOPOLOGY_H */ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 1072502976df..0a9c3024326d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2532,6 +2532,72 @@ void arch_scale_freq_tick(void) } #endif +#ifdef CONFIG_IPC_CLASSES +DECLARE_STATIC_KEY_FALSE(sched_ipcc); + +static inline bool sched_ipcc_enabled(void) +{ + return static_branch_unlikely(&sched_ipcc); +} + +#ifndef arch_update_ipcc +/** + * arch_update_ipcc() - Update the IPC class of the current task + * @curr: The current task + * + * Request that the IPC classification of @curr is updated. + * + * Returns: none + */ +static __always_inline +void arch_update_ipcc(struct task_struct *curr) +{ +} +#endif + +#ifndef arch_get_ipcc_score + +#define SCHED_IPCC_SCORE_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) +/** + * arch_get_ipcc_score() - Get the IPC score of a class of task + * @ipcc: The IPC class + * @cpu: A CPU number + * + * The IPC performance scores reflects (but it is not identical to) the number + * of instructions retired per cycle for a given IPC class. It is a linear and + * abstract metric. Higher scores reflect better performance. + * + * The IPC score can be normalized with respect to the class, i, with the + * highest IPC score on the CPU, c, with highest performance: + * + * IPC(i, c) + * ------------------------------------ * SCHED_IPCC_SCORE_SCALE + * max(IPC(i, c) : (i, c)) + * + * Scheduling schemes that want to use the IPC score along with other + * normalized metrics for scheduling (e.g., CPU capacity) may need to normalize + * it. + * + * Other scheduling schemes (e.g., asym_packing) do not need normalization. + * + * Returns the performance score of an IPC class, @ipcc, when running on @cpu. + * Error when either @ipcc or @cpu are invalid. + */ +static __always_inline +unsigned long arch_get_ipcc_score(unsigned short ipcc, int cpu) +{ + return SCHED_IPCC_SCORE_SCALE; +} +#endif +#else /* CONFIG_IPC_CLASSES */ + +#define arch_get_ipcc_score(ipcc, cpu) (-EINVAL) +#define arch_update_ipcc(curr) + +static inline bool sched_ipcc_enabled(void) { return false; } + +#endif /* CONFIG_IPC_CLASSES */ + #ifndef arch_scale_freq_capacity /** * arch_scale_freq_capacity - get the frequency scale factor of a given CPU. diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index d93c3379e901..8380bb7f0cd9 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -670,6 +670,15 @@ DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); +#ifdef CONFIG_IPC_CLASSES +DEFINE_STATIC_KEY_FALSE(sched_ipcc); + +void sched_enable_ipc_classes(void) +{ + static_branch_enable_cpuslocked(&sched_ipcc); +} +#endif + static void update_top_cache_domain(int cpu) { struct sched_domain_shared *sds = NULL;