From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754159AbcFPJrX (ORCPT ); Thu, 16 Jun 2016 05:47:23 -0400 Received: from mga01.intel.com ([192.55.52.88]:41320 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754110AbcFPJqs (ORCPT ); Thu, 16 Jun 2016 05:46:48 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,478,1459839600"; d="scan'208";a="719988202" From: Yuyang Du To: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org Cc: umgwanakikbuti@gmail.com, bsegall@google.com, pjt@google.com, morten.rasmussen@arm.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, matt@codeblueprint.co.uk, Yuyang Du Subject: [RFC PATCH 10/11] sched: Add sched_llc_complete static key to specify whether the LLC covers all CPUs Date: Thu, 16 Jun 2016 09:49:34 +0800 Message-Id: <1466041775-4528-11-git-send-email-yuyang.du@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1466041775-4528-1-git-send-email-yuyang.du@intel.com> References: <1466041775-4528-1-git-send-email-yuyang.du@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This static key tells whether all CPUs share last level cache, which is common in single-socket x86 boxes. This allows us to know better to fast select an idle sibling in select_task_rq_fair(). Signed-off-by: Yuyang Du --- kernel/sched/core.c | 9 +++++++++ kernel/sched/sched.h | 4 ++++ 2 files changed, 13 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0a332ed..3f26fea 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7303,6 +7303,14 @@ static void sched_init_smt(void) static inline void sched_init_smt(void) { } #endif +DEFINE_STATIC_KEY_TRUE(sched_llc_complete); + +static void sched_init_llc_complete(void) +{ + if (cpumask_weight(cpu_active_mask) > per_cpu(sd_llc_size, 0)) + static_branch_disable(&sched_llc_complete); +} + void __init sched_init_smp(void) { cpumask_var_t non_isolated_cpus; @@ -7334,6 +7342,7 @@ void __init sched_init_smp(void) init_sched_dl_class(); sched_init_smt(); + sched_init_llc_complete(); sched_smp_initialized = true; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 654bc65..f11c5dd 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1828,3 +1828,7 @@ static inline void update_idle_core(struct rq *rq) #else static inline void update_idle_core(struct rq *rq) { } #endif + +#ifdef CONFIG_SCHED_MC +extern struct static_key_true sched_llc_complete; +#endif -- 1.7.9.5