From patchwork Wed Jun 6 16:38:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 10450647 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A325A6053F for ; Wed, 6 Jun 2018 16:39:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 92F4129A34 for ; Wed, 6 Jun 2018 16:39:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 875F929A42; Wed, 6 Jun 2018 16:39:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2D0DD29A34 for ; Wed, 6 Jun 2018 16:39:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=kGoDD+lb2ANg6GRymSrGVV9kDdh2sKjyHjlYvyAKynY=; b=EDg Tv7/EqHYhN9Gp3JrFUgj6WznYx+n9H1raHs0HYb6BZABApMM2pVYoTNzM4sCjNN1nBpNsL25Antqn fpKyDOzzBC89NA9vS7rA+WJi6wxAKOA5MyUfPuSi8SWW51b0Y4Iq80l4hNPj1V3C6h1FTMItbzwtJ Lk/kw3LdYfbc9jwUSCzzuwo7reA5UWceFTyDe1bU8wiKfuTYBcH8aIES04j4tiA6fOEg7tUpnoIPk QE44Z8nQgek39Swrc13BuMshxs9LchCdATVSOiNdlHWVPSCOhsF7EwJg35JynWfurefP/Tw8uWqAX LnKFr68PMuPh64zTeurIetg3liAbwQQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fQbSm-0004RW-Dh; Wed, 06 Jun 2018 16:39:08 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fQbSi-0004QP-Iw for linux-arm-kernel@lists.infradead.org; Wed, 06 Jun 2018 16:39:06 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 682DA15AB; Wed, 6 Jun 2018 09:38:51 -0700 (PDT) Received: from beelzebub.austin.arm.com (beelzebub.austin.arm.com [10.118.12.119]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DC2EC3F25D; Wed, 6 Jun 2018 09:38:50 -0700 (PDT) From: Jeremy Linton To: Sudeep.Holla@arm.com Subject: [PATCH v2] arm64: topology: Avoid checking numa mask for scheduler MC selection Date: Wed, 6 Jun 2018 11:38:46 -0500 Message-Id: <20180606163846.495725-1-jeremy.linton@arm.com> X-Mailer: git-send-email 2.14.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180606_093904_653742_D49B0D8D X-CRM114-Status: GOOD ( 14.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ard.biesheuvel@linaro.org, Catalin.Marinas@arm.com, Will.Deacon@arm.com, linux-kernel@vger.kernel.org, Jeremy Linton , linux-acpi@vger.kernel.org, geert@linux-m68k.org, Robin.Murphy@arm.com, Morten.Rasmussen@arm.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The numa mask subset check can often lead to system hang or crash during CPU hotplug and system suspend operation if NUMA is disabled. This is mostly observed on HMP systems where the CPU compute capacities are different and ends up in different scheduler domains. Since cpumask_of_node is returned instead core_sibling, the scheduler is confused with incorrect cpumasks(e.g. one CPU in two different sched domains at the same time) on CPU hotplug. Lets disable the NUMA siblings checks for the time being, as NUMA in socket machines have LLC's that will assure that the scheduler topology isn't "borken". The NUMA check exists to assure that if a LLC within a socket crosses NUMA nodes/chiplets the scheduler domains remain consistent. This code will likely have to be re-enabled in the near future once the NUMA mask story is sorted. At the moment its not necessary because the NUMA in socket machines LLC's are contained within the NUMA domains. Further, as a defensive mechanism during hot-plug, lets assure that the LLC siblings are also masked. Reported-by: Geert Uytterhoeven Reviewed-by: Sudeep Holla Signed-off-by: Jeremy Linton Tested-by: Geert Uytterhoeven --- arch/arm64/kernel/topology.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 7415c166281f..f845a8617812 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -215,13 +215,8 @@ EXPORT_SYMBOL_GPL(cpu_topology); const struct cpumask *cpu_coregroup_mask(int cpu) { - const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu)); + const cpumask_t *core_mask = &cpu_topology[cpu].core_sibling; - /* Find the smaller of NUMA, core or LLC siblings */ - if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) { - /* not numa in package, lets use the package siblings */ - core_mask = &cpu_topology[cpu].core_sibling; - } if (cpu_topology[cpu].llc_id != -1) { if (cpumask_subset(&cpu_topology[cpu].llc_siblings, core_mask)) core_mask = &cpu_topology[cpu].llc_siblings; @@ -239,8 +234,10 @@ static void update_siblings_masks(unsigned int cpuid) for_each_possible_cpu(cpu) { cpu_topo = &cpu_topology[cpu]; - if (cpuid_topo->llc_id == cpu_topo->llc_id) + if (cpuid_topo->llc_id == cpu_topo->llc_id) { cpumask_set_cpu(cpu, &cpuid_topo->llc_siblings); + cpumask_set_cpu(cpuid, &cpu_topo->llc_siblings); + } if (cpuid_topo->package_id != cpu_topo->package_id) continue;