From patchwork Tue Nov 28 22:58:36 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Bringmann X-Patchwork-Id: 842354 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3ymfKs5S5kz9sDB for ; Wed, 29 Nov 2017 10:01:21 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3ymfKs4VqtzDrvP for ; Wed, 29 Nov 2017 10:01:21 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=mwb@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3ymfH66Fh7zDrLt for ; Wed, 29 Nov 2017 09:58:58 +1100 (AEDT) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vASMreD0058124 for ; Tue, 28 Nov 2017 17:58:56 -0500 Received: from e13.ny.us.ibm.com (e13.ny.us.ibm.com [129.33.205.203]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ehbb2yrhh-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 28 Nov 2017 17:58:55 -0500 Received: from localhost by e13.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 28 Nov 2017 17:58:54 -0500 Received: from b01cxnp22033.gho.pok.ibm.com (9.57.198.23) by e13.ny.us.ibm.com (146.89.104.200) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 28 Nov 2017 17:58:52 -0500 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id vASMwqlt41156760; Tue, 28 Nov 2017 22:58:52 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B5C85B204D; Tue, 28 Nov 2017 17:56:00 -0500 (EST) Received: from oc5000245537.ibm.com (unknown [9.53.92.243]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP id 48E3BB2046; Tue, 28 Nov 2017 17:56:00 -0500 (EST) To: linuxppc-dev@lists.ozlabs.org From: Michael Bringmann Subject: [PATCH V8 1/3] powerpc/nodes: Ensure enough nodes avail for operations In-Reply-To: <79bd4c96-2381-c9b1-8222-b350e069655b@linux.vnet.ibm.com> Organization: IBM Linux Technology Center Date: Tue, 28 Nov 2017 16:58:36 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 17112822-0008-0000-0000-000002A77977 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008121; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000242; SDB=6.00952622; UDB=6.00481259; IPR=6.00732703; BA=6.00005719; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00018236; XFM=3.00000015; UTC=2017-11-28 22:58:53 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17112822-0009-0000-0000-000037711D5A Message-Id: <4faec177-a704-1404-c7ae-7f064153de2b@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-11-28_12:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1711280305 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nathan Fontenot , Michael Bringmann Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" On powerpc systems which allow 'hot-add' of CPU or memory resources, it may occur that the new resources are to be inserted into nodes that were not used for these resources at bootup. In the kernel, any node that is used must be defined and initialized. These empty nodes may occur when, * Dedicated vs. shared resources. Shared resources require information such as the VPHN hcall for CPU assignment to nodes. Associativity decisions made based on dedicated resource rules, such as associativity properties in the device tree, may vary from decisions made using the values returned by the VPHN hcall. * memoryless nodes at boot. Nodes need to be defined as 'possible' at boot for operation with other code modules. Previously, the powerpc code would limit the set of possible nodes to those which have memory assigned at boot, and were thus online. Subsequent add/remove of CPUs or memory would only work with this subset of possible nodes. * memoryless nodes with CPUs at boot. Due to the previous restriction on nodes, nodes that had CPUs but no memory were being collapsed into other nodes that did have memory at boot. In practice this meant that the node assignment presented by the runtime kernel differed from the affinity and associativity attributes presented by the device tree or VPHN hcalls. Nodes that might be known to the pHyp were not 'possible' in the runtime kernel because they did not have memory at boot. This patch ensures that sufficient nodes are defined to support configuration requirements after boot, as well as at boot. This patch set fixes a couple of problems. * Nodes known to powerpc to be memoryless at boot, but to have CPUs in them are allowed to be 'possible' and 'online'. Memory allocations for those nodes are taken from another node that does have memory until and if memory is hot-added to the node. * Nodes which have no resources assigned at boot, but which may still be referenced subsequently by affinity or associativity attributes, are kept in the list of 'possible' nodes for powerpc. Hot-add of memory or CPUs to the system can reference these nodes and bring them online instead of redirecting to one of the set of nodes that were known to have memory at boot. This patch extracts the value of the lowest domain level (number of allocable resources) from the device tree property "ibm,max-associativity-domains" to use as the maximum number of nodes to setup as possibly available in the system. This new setting will override the instruction, nodes_and(node_possible_map, node_possible_map, node_online_map); presently seen in the function arch/powerpc/mm/numa.c:initmem_init(). If the "ibm,max-associativity-domains" property is not present at boot, no operation will be performed to define or enable additional nodes, or enable the above 'nodes_and()'. Signed-off-by: Michael Bringmann Reviewed-by: Nathan Fontenot --- Changes in V8: -- Remove unneeded pr_info() statement --- arch/powerpc/mm/numa.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index adb6364f..735e3fd 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -892,6 +892,34 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn) NODE_DATA(nid)->node_spanned_pages = spanned_pages; } +static void __init find_possible_nodes(void) +{ + struct device_node *rtas; + u32 numnodes, i; + + if (min_common_depth <= 0) + return; + + rtas = of_find_node_by_path("/rtas"); + if (!rtas) + return; + + if (of_property_read_u32_index(rtas, + "ibm,max-associativity-domains", + min_common_depth, &numnodes)) + goto out; + + for (i = 0; i < numnodes; i++) { + if (!node_possible(i)) { + setup_node_data(i, 0, 0); + node_set(i, node_possible_map); + } + } + +out: + of_node_put(rtas); +} + void __init initmem_init(void) { int nid, cpu; @@ -905,12 +933,15 @@ void __init initmem_init(void) memblock_dump_all(); /* - * Reduce the possible NUMA nodes to the online NUMA nodes, - * since we do not support node hotplug. This ensures that we - * lower the maximum NUMA node ID to what is actually present. + * Modify the set of possible NUMA nodes to reflect information + * available about the set of online nodes, and the set of nodes + * that we expect to make use of for this platform's affinity + * calculations. */ nodes_and(node_possible_map, node_possible_map, node_online_map); + find_possible_nodes(); + for_each_online_node(nid) { unsigned long start_pfn, end_pfn; From patchwork Tue Nov 28 22:58:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Bringmann X-Patchwork-Id: 842355 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3ymfMg3Scqz9sBd for ; Wed, 29 Nov 2017 10:02:55 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3ymfMg2Z5xzDsFV for ; Wed, 29 Nov 2017 10:02:55 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=mwb@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3ymfHB4lYdzDrp7 for ; Wed, 29 Nov 2017 09:59:02 +1100 (AEDT) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vASMrbSi073083 for ; Tue, 28 Nov 2017 17:59:00 -0500 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ehgavhtvm-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 28 Nov 2017 17:59:00 -0500 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 28 Nov 2017 17:58:59 -0500 Received: from b01cxnp23032.gho.pok.ibm.com (9.57.198.27) by e15.ny.us.ibm.com (146.89.104.202) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 28 Nov 2017 17:58:56 -0500 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id vASMwuXt41222168; Tue, 28 Nov 2017 22:58:56 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7177EB204D; Tue, 28 Nov 2017 17:56:04 -0500 (EST) Received: from oc5000245537.ibm.com (unknown [9.53.92.243]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP id 1100DB2046; Tue, 28 Nov 2017 17:56:04 -0500 (EST) To: linuxppc-dev@lists.ozlabs.org From: Michael Bringmann Subject: [PATCH V8 2/3] poserpc/initnodes: Ensure nodes initialized for hotplug In-Reply-To: <79bd4c96-2381-c9b1-8222-b350e069655b@linux.vnet.ibm.com> Organization: IBM Linux Technology Center Date: Tue, 28 Nov 2017 16:58:40 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 17112822-0036-0000-0000-000002931EA9 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008121; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000242; SDB=6.00952622; UDB=6.00481259; IPR=6.00732703; BA=6.00005719; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00018236; XFM=3.00000015; UTC=2017-11-28 22:58:57 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17112822-0037-0000-0000-00004283E39E Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-11-28_12:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1711280305 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nathan Fontenot , Michael Bringmann Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" On powerpc 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. Important characteristics of the nodes and operating environment include: * Dedicated vs. shared CPUs. Shared CPUs require information such as the VPHN hcall for CPU assignment to nodes, since shared CPUs have their affinity set to node 0 at boot and when hot-added. Associativity decisions made based on dedicated resource rules, such as associativity properties in the device tree, may vary from decisions made using the values returned by the VPHN hcall. * memoryless nodes at boot. Nodes need to be defined as 'possible' at boot for operation with other code modules. Previously, the powerpc code would limit the set of possible nodes to those which have memory assigned at boot, and were thus online. Subsequent add/remove of CPUs or memory would only work with this subset of possible nodes. * memoryless nodes with CPUs at boot. Due to the previous restriction on nodes, nodes that had CPUs but no memory were being collapsed into other nodes that did have memory at boot. In practice this meant that the node assignment presented by the runtime kernel differed from the affinity and associativity attributes presented by the device tree or VPHN hcalls. Nodes that might be known to the pHyp were not 'possible' in the runtime kernel because they did not have memory at boot. 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. The problems of interest include, * Nodes known to powerpc to be memoryless at boot, but to have CPUs in them are allowed to be 'possible' and 'online'. Memory allocations for those nodes are taken from another node that does have memory until and if memory is hot-added to the node. * Nodes which have no resources assigned at boot, but which may still be referenced subsequently by affinity or associativity attributes, are kept in the list of 'possible' nodes for powerpc. Hot-add of memory or CPUs to the system can reference these nodes and bring them online instead of redirecting the references to one of the set of nodes known to have memory at boot. Note that this software operates under the context of CPU hotplug. We are not doing memory hotplug in this code, but rather updating the kernel's CPU topology (i.e. arch_update_cpu_topology / numa_update_cpu_topology). We are initializing a node that may be used by CPUs or memory before it can be referenced as invalid by a CPU hotplug operation. CPU hotplug operations are protected by a range of APIs including cpu_maps_update_begin/cpu_maps_update_done, cpus_read/write_lock / cpus_read/write_unlock, device locks, and more. Memory hotplug operations, including try_online_node, are protected by mem_hotplug_begin/mem_hotplug_done, device locks, and more. In the case of CPUs being hot-added to a previously memoryless node, the try_online_node operation occurs wholly within the CPU locks with no overlap. Using HMC hot-add/hot-remove operations, we have been able to add and remove CPUs to any possible node without failures. HMC operations involve a degree self-serialization, though. Signed-off-by: Michael Bringmann Reviewed-by: Nathan Fontenot --- Changes in V8: -- Clarify 'resources' as CPUs in patch description regarding VPHN call. Add another clause to statement mentioning that shared CPUs start in node 0, and are finally assigned per VPHN information. -- Rename 'find_cpu_nid' to 'find_and_online_cpu_nid' for better clarity of its function. -- Restore '__init' tag to definition of 'setup_node_data' --- arch/powerpc/mm/numa.c | 49 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 39 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 735e3fd..6b08dd8 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); @@ -910,10 +910,8 @@ static void __init find_possible_nodes(void) goto out; 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: @@ -1309,6 +1307,42 @@ static long vphn_get_associativity(unsigned long cpu, return rc; } +static inline int find_and_online_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 @@ -1376,7 +1410,6 @@ 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; @@ -1414,11 +1447,7 @@ 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_and_online_cpu_nid(cpu); if (new_nid == numa_cpu_lookup_table[cpu]) { cpumask_andnot(&cpu_associativity_changes_mask, From patchwork Tue Nov 28 22:58:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Bringmann X-Patchwork-Id: 842356 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3ymfPs1GnCz9sDB for ; Wed, 29 Nov 2017 10:04:49 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3ymfPr6TYnzDrZ4 for ; Wed, 29 Nov 2017 10:04:48 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=mwb@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3ymfHF5s0BzDrb3 for ; Wed, 29 Nov 2017 09:59:05 +1100 (AEDT) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vASMrdak123651 for ; Tue, 28 Nov 2017 17:59:03 -0500 Received: from e18.ny.us.ibm.com (e18.ny.us.ibm.com [129.33.205.208]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ehfhfuskc-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 28 Nov 2017 17:59:03 -0500 Received: from localhost by e18.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 28 Nov 2017 17:59:02 -0500 Received: from b01cxnp23033.gho.pok.ibm.com (9.57.198.28) by e18.ny.us.ibm.com (146.89.104.205) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 28 Nov 2017 17:59:00 -0500 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id vASMwxu252494414; Tue, 28 Nov 2017 22:58:59 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F35E0B2050; Tue, 28 Nov 2017 17:56:07 -0500 (EST) Received: from oc5000245537.ibm.com (unknown [9.53.92.243]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP id A5F49B204E; Tue, 28 Nov 2017 17:56:07 -0500 (EST) From: Michael Bringmann To: linuxppc-dev@lists.ozlabs.org In-Reply-To: <79bd4c96-2381-c9b1-8222-b350e069655b@linux.vnet.ibm.com> Subject: [PATCH V8 3/3] hotplug/cpu: Fix crash with memoryless nodes Organization: IBM Linux Technology Center Date: Tue, 28 Nov 2017 16:58:43 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 17112822-0044-0000-0000-000003B67A2E X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008121; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000242; SDB=6.00952622; UDB=6.00481259; IPR=6.00732703; BA=6.00005719; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00018236; XFM=3.00000015; UTC=2017-11-28 22:59:01 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17112822-0045-0000-0000-000007E5A62B Message-Id: <55ff4b6a-7f43-e171-d214-cf10d466aa71@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-11-28_12:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1711280305 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nathan Fontenot , Michael Bringmann Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" On powerpc systems with shared configurations of CPUs and memory and memoryless nodes at boot, an event ordering problem was observed on a SLES12 build platforms with the hot-add of CPUs to the memoryless nodes. * The most common error occurred when the memory SLAB driver attempted to reference the memoryless node to which a CPU was being added before the kernel had finished initializing all of the data structures for the CPU and exited 'device_online' under DLPAR/hot-add. Normally the memoryless node would be initialized through the call path device_online ... arch_update_cpu_topology ... find_cpu_nid ... try_online_node. This patch ensures that the powerpc node will be initialized as early as possible, even if it was memoryless and CPU-less at the point when we are trying to hot-add a new CPU to it. Signed-off-by: Michael Bringmann Reviewed-by: Nathan Fontenot --- Changes in V8: -- Change a 'printk(KERN_INFO ...)' statement to be a pr_debug() statement. -- Rename 'find_cpu_nid' to 'find_and_online_cpu_nid' for better clarity of its function. --- arch/powerpc/mm/numa.c | 4 +++- arch/powerpc/platforms/pseries/hotplug-cpu.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 6b08dd8..a182f9e 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1307,7 +1307,7 @@ static long vphn_get_associativity(unsigned long cpu, return rc; } -static inline int find_and_online_cpu_nid(int cpu) +int find_and_online_cpu_nid(int cpu) { __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0}; int new_nid; @@ -1340,6 +1340,8 @@ static inline int find_and_online_cpu_nid(int cpu) #endif } + pr_debug("%s:%d cpu %d nid %d\n", __FUNCTION__, __LINE__, + cpu, new_nid); return new_nid; } diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index a7d14aa7..dceb514 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -340,6 +340,8 @@ static void pseries_remove_processor(struct device_node *np) cpu_maps_update_done(); } +extern int find_and_online_cpu_nid(int cpu); + static int dlpar_online_cpu(struct device_node *dn) { int rc = 0; @@ -364,6 +366,7 @@ static int dlpar_online_cpu(struct device_node *dn) != CPU_STATE_OFFLINE); cpu_maps_update_done(); timed_topology_update(1); + find_and_online_cpu_nid(cpu); rc = device_online(get_cpu_device(cpu)); if (rc) goto out;