From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755060AbdKAS6b (ORCPT ); Wed, 1 Nov 2017 14:58:31 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43942 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755020AbdKAS62 (ORCPT ); Wed, 1 Nov 2017 14:58:28 -0400 To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org From: Michael Bringmann Organization: IBM Linux Technology Center Cc: Michael Bringmann , Nathan Fontenot , Michael Ellerman , John Allen , Tyrel Datwyler , Thomas Falcon Subject: [PATCH V6 2/2] pseries/initnodes: Ensure nodes initialized for hotplug In-Reply-To: Date: Wed, 1 Nov 2017 13:58:23 -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: 17110118-0040-0000-0000-000003BBDBBA X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007993; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000239; SDB=6.00939708; UDB=6.00473792; IPR=6.00719969; BA=6.00005666; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017824; XFM=3.00000015; UTC=2017-11-01 18:58:27 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17110118-0041-0000-0000-000007B0EEF3 Message-Id: <129c79ac-3fc6-95c4-1eef-43f862c510c3@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-11-01_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1711010247 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 CPUs into nodes that are memoryless during system execution after boot. Signed-off-by: Michael Bringmann --- Changes in V6: -- Add some needed node initialization to runtime code that maps CPUs based on VPHN associativity -- Add error checks and alternate recovery for compile flag CONFIG_MEMORY_HOTPLUG -- Add alternate node selection recovery for !CONFIG_MEMORY_HOTPLUG --- arch/powerpc/mm/numa.c | 51 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 40 insertions(+), 11 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 334a1ff..163f4cc 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); @@ -913,10 +913,8 @@ static void __init find_possible_nodes(void) min_common_depth); for (i = 0; i < numnodes; i++) { - if (!node_possible(i)) { - setup_node_data(i, 0, 0); + if (!node_possible(i)) node_set(i, node_possible_map); - } } out: @@ -1312,6 +1310,42 @@ 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; + + if (NODE_DATA(new_nid) == NULL) { +#ifdef CONFIG_MEMORY_HOTPLUG + /* + * Need to ensure that NODE_DATA is initialized + * for a node from available memory (see + * memblock_alloc_try_nid). If unable to init + * the node, then default to nearest node that + * has memory installed. + */ + if (try_online_node(new_nid)) + new_nid = first_online_node; +#else + /* + * Default to using the nearest node that has + * memory installed. Otherwise, it would be + * necessary to patch the kernel MM code to deal + * with more memoryless-node error conditions. + */ + new_nid = first_online_node; +#endif + } + + 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 @@ -1379,7 +1413,6 @@ 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; @@ -1417,11 +1450,7 @@ 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,