From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tadeusz Struk Subject: Re: [PATCH 2/2] crypto: qat - Enforce valid numa configuration. Date: Thu, 09 Oct 2014 09:14:17 -0700 Message-ID: <5436B459.4090503@intel.com> References: <20141008173750.13714.49713.stgit@tstruk-mobl1> <20141008173853.13714.47458.stgit@tstruk-mobl1> <54357B02.8080008@redhat.com> <54357E5B.2090401@intel.com> <54358400.5060405@redhat.com> <54358918.7030808@intel.com> <54358A06.2080605@redhat.com> <54358FC6.8060500@intel.com> <54367016.3070709@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: herbert@gondor.apana.org.au, bruce.w.allan@intel.com, qat-linux@intel.com, john.griffin@intel.com, linux-crypto@vger.kernel.org, naleksan@redhat.com, davem@davemloft.net To: Prarit Bhargava Return-path: Received: from mga11.intel.com ([192.55.52.93]:18664 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751197AbaJIQQh (ORCPT ); Thu, 9 Oct 2014 12:16:37 -0400 In-Reply-To: <54367016.3070709@redhat.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On 10/09/2014 04:23 AM, Prarit Bhargava wrote: >> int numa_node; /* NUMA node this device is close to */ >> > ... > That's just bad english. The numa node value (for pci devices) is > read from the ACPI tables on the system and represents the node that > the pci_dev is connected to. > >> > }; >> > >> > In case when there are two nodes and only node 0 has memory, >> > dev->numa_node will be 0 even though the device will be connected to the >> > pci root port of node 1. > Your calculation completely falls apart and returns incorrect values when > cpu hotplug is used or if there are multi-socket nodes (as was the case > on the system that panicked), or if one uses the new cluster-on-die mode. This calculation is sole for multi-socket configuration. This is why is was introduced and what it was tested for. There is no point discussing NUMA for single-socket configuration. Single socket configurations are not NUMA. In this case dev->numa_node is usually equal to NUMA_NO_NODE (-1) and adf_get_dev_node_id(pdev) will always return 0; Please confirm that, but I think the system it panicked on was a two sockets system with only node 0 populated with memory and accelerator plugged it to node 1 (phys_proc_id == 1). In this case adf_get_dev_node_id(pdev) returned 1 and this was passed to kzalloc_node(size, GFP_KERNEL, 1) and because there was no memory on node 1 kzalloc_node() panicked. This patch will make sure that this will not happen and that the configuration will be optimal.