From patchwork Tue Jun 21 19:20:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12889661 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4F178C43334 for ; Tue, 21 Jun 2022 19:31:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uOZtG+A13AiCuOdw6RnH/tOwPA2rZzsqwd5l1gNbeH8=; b=G+QATHcl09x8M9 cMkMb/4jcCplDuVN0yRY5Bylx2tso3XJ7K8iLdIkLnSrrResmZT1I+pXBiop5ujotoYnh2YuHMyIR VjR576iHRhw3OVy3rHL8JC+yPvNr7PobMPQ4fi0OFq2qxde9wLQXsPMUW2c8T83B4ay0z5Vy2w4eG r2kpcmm7t1axjeeTRCOqqG3T+TBmrs4Rb/C0OEXT656clUJNPtfRUL6RNVF14kd7N6ZWIqFKbdCoa Lc+aWTuffuSdugPoJXk5l2y+B2e+/DwRCfvibfbKrWisDtrHD2M8e91okEN11uHf70TEOnZe9oPbN UcIe1mKBIvIiTp7kuXwg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o3jb8-006tp5-6c; Tue, 21 Jun 2022 19:31:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o3jRC-006oA4-3C; Tue, 21 Jun 2022 19:21:24 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DC6E8165C; Tue, 21 Jun 2022 12:21:21 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D18AE3F792; Tue, 21 Jun 2022 12:21:19 -0700 (PDT) From: Sudeep Holla To: linux-kernel@vger.kernel.org, Greg KH Cc: Sudeep Holla , Atish Patra , Atish Patra , Vincent Guittot , Dietmar Eggemann , Qing Wang , Rob Herring , "Rafael J . Wysocki" , Ionela Voinescu , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Darren Hart Subject: [PATCH v4 17/20] arch_topology: Limit span of cpu_clustergroup_mask() Date: Tue, 21 Jun 2022 20:20:31 +0100 Message-Id: <20220621192034.3332546-18-sudeep.holla@arm.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220621192034.3332546-1-sudeep.holla@arm.com> References: <20220621192034.3332546-1-sudeep.holla@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220621_122122_263423_64C4440F X-CRM114-Status: GOOD ( 11.26 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Ionela Voinescu Currently the cluster identifier is not set on DT based platforms. The reset or default value is -1 for all the CPUs. Once we assign the cluster identifier values correctly, the cluster_sibling mask will be populated and returned by cpu_clustergroup_mask() to contribute in the creation of the CLS scheduling domain level, if SCHED_CLUSTER is enabled. To avoid topologies that will result in questionable or incorrect scheduling domains, impose restrictions regarding the span of clusters, as presented to scheduling domains building code: cluster_sibling should not span more or the same CPUs as cpu_coregroup_mask(). This is needed in order to obtain a strict separation between the MC and CLS levels, and maintain the same domains for existing platforms in the presence of CONFIG_SCHED_CLUSTER, where the new cluster information is redundant and irrelevant for the scheduler. While previously the scheduling domain builder code would have removed MC as redundant and kept CLS if SCHED_CLUSTER was enabled and the cpu_coregroup_mask() and cpu_clustergroup_mask() spanned the same CPUs, now CLS will be removed and MC kept. Cc: Darren Hart Signed-off-by: Ionela Voinescu Signed-off-by: Sudeep Holla --- drivers/base/arch_topology.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 42448a5a9412..39be5dbaf4da 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -675,6 +675,14 @@ const struct cpumask *cpu_coregroup_mask(int cpu) const struct cpumask *cpu_clustergroup_mask(int cpu) { + /* + * Forbid cpu_clustergroup_mask() to span more or the same CPUs as + * cpu_coregroup_mask(). + */ + if (cpumask_subset(cpu_coregroup_mask(cpu), + &cpu_topology[cpu].cluster_sibling)) + return get_cpu_mask(cpu); + return &cpu_topology[cpu].cluster_sibling; }