From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752028AbdJZUh5 (ORCPT ); Thu, 26 Oct 2017 16:37:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:35250 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751651AbdJZUh4 (ORCPT ); Thu, 26 Oct 2017 16:37:56 -0400 From: Michael Bringmann Organization: IBM Linux Technology Center Cc: Michael Ellerman , Michael Bringmann , John Allen , Nathan Fontenot , Tyrel Datwyler , Thomas Falcon To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH V5 2/2] pseries/initnodes: Ensure nodes initialized for hotplug In-Reply-To: <237b5727-7329-5608-5fa1-0cd465415db2@linux.vnet.ibm.com> Date: Thu, 26 Oct 2017 15:36:50 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 17102620-0048-0000-0000-000001FBD29C X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007956; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000239; SDB=6.00936883; UDB=6.00472155; IPR=6.00717146; BA=6.00005660; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017730; XFM=3.00000015; UTC=2017-10-26 20:36:52 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17102620-0049-0000-0000-000042FDE0C5 Message-Id: <51cdbb88-4ead-7bf7-6e18-297d9b7e1e75@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-26_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 lowpriorityscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710260259 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org pseries/nodes: On pseries systems which allow 'hot-add' of CPU, it may occur that the new resources are to be inserted into nodes that were not used for memory resources at bootup. Many different configurations of PowerPC resources may need to be supported depending upon the environment. This patch fixes some problems encountered at runtime with configurations that support memory-less nodes, or that hot-add resources during system execution after boot. Signed-off-by: Michael Bringmann --- Changes in V5: -- Reorganize code used to associatively map CPUs to nodes and ensure initialization of nodes at runtime. --- arch/powerpc/mm/numa.c | 45 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 18fc40d..4d615a4 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -551,7 +551,7 @@ static int numa_setup_cpu(unsigned long lcpu) nid = of_node_to_nid_single(cpu); out_present: - if (nid < 0 || !node_online(nid)) + if (nid < 0 || !node_possible(nid)) nid = first_online_node; map_cpu_to_node(lcpu, nid); @@ -867,7 +867,7 @@ void __init dump_numa_cpu_topology(void) } /* Initialize NODE_DATA for a node on the local memory */ -static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn) +static void setup_node_data(int nid, u64 start_pfn, u64 end_pfn) { u64 spanned_pages = end_pfn - start_pfn; const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES); @@ -1310,6 +1310,40 @@ static long vphn_get_associativity(unsigned long cpu, return rc; } +static inline int find_cpu_nid(int cpu) +{ + __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0}; + int new_nid; + + /* Use associativity from first thread for all siblings */ + vphn_get_associativity(cpu, associativity); + new_nid = associativity_to_nid(associativity); + if (new_nid < 0 || !node_possible(new_nid)) + new_nid = first_online_node; + + /* + * Need to ensure that NODE_DATA is allocated/initialized for + * a node from available memory (see memblock_alloc_try_nid). + * Code executed after boot (like local_memory_node) may not + * know enough to recover fully for memoryless nodes. + */ + if (NODE_DATA(new_nid) == NULL) { + setup_node_data(new_nid, 0, 0); + try_online_node(new_nid); + + /* + * Node structures successfully initialized, but + * we still need the memoryliess node to be offline. + */ + node_set_offline(new_nid); + } + + if (NODE_DATA(new_nid)->node_spanned_pages == 0) + return first_online_node; + + return new_nid; +} + /* * Update the CPU maps and sysfs entries for a single CPU when its NUMA * characteristics change. This function doesn't perform any locking and is @@ -1377,7 +1411,6 @@ int numa_update_cpu_topology(bool cpus_locked) { unsigned int cpu, sibling, changed = 0; struct topology_update_data *updates, *ud; - __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0}; cpumask_t updated_cpus; struct device *dev; int weight, new_nid, i = 0; @@ -1415,11 +1448,7 @@ int numa_update_cpu_topology(bool cpus_locked) continue; } - /* Use associativity from first thread for all siblings */ - vphn_get_associativity(cpu, associativity); - new_nid = associativity_to_nid(associativity); - if (new_nid < 0 || !node_online(new_nid)) - new_nid = first_online_node; + new_nid = find_cpu_nid(cpu); if (new_nid == numa_cpu_lookup_table[cpu]) { cpumask_andnot(&cpu_associativity_changes_mask,