From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fengguang Wu Subject: [RFC][PATCH v2 08/21] mm: introduce and export pgdat peer_node Date: Wed, 26 Dec 2018 21:14:54 +0800 Message-ID: <20181226133351.521151384@intel.com> References: <20181226131446.330864849@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Linux Memory Management List , Fan Du , Fengguang Wu To: Andrew Morton Return-path: cc: kvm@vger.kernel.org Cc: LKML cc: Yao Yuan cc: Peng Dong cc: Huang Ying CC: Liu Jingqi cc: Dong Eddie cc: Dave Hansen cc: Zhang Yi cc: Dan Williams Content-Disposition: inline; filename=0019-mm-Introduce-and-export-peer_node-for-pgdat.patch Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org From: Fan Du Each CPU socket can have 1 DRAM and 1 PMEM node, we call them "peer nodes". Migration between DRAM and PMEM will by default happen between peer nodes. It's a temp solution. In multiple memory layers, a node can have both promotion and demotion targets instead of a single peer node. User space may also be able to infer promotion/demotion targets based on future HMAT info. Signed-off-by: Fan Du Signed-off-by: Fengguang Wu --- drivers/base/node.c | 11 +++++++++++ include/linux/mmzone.h | 12 ++++++++++++ mm/page_alloc.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 52 insertions(+) --- linux.orig/drivers/base/node.c 2018-12-23 19:39:51.647261099 +0800 +++ linux/drivers/base/node.c 2018-12-23 19:39:51.643261112 +0800 @@ -242,6 +242,16 @@ static ssize_t type_show(struct device * } static DEVICE_ATTR(type, S_IRUGO, type_show, NULL); +static ssize_t peer_node_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int nid = dev->id; + struct pglist_data *pgdat = NODE_DATA(nid); + + return sprintf(buf, "%d\n", pgdat->peer_node); +} +static DEVICE_ATTR(peer_node, S_IRUGO, peer_node_show, NULL); + static struct attribute *node_dev_attrs[] = { &dev_attr_cpumap.attr, &dev_attr_cpulist.attr, @@ -250,6 +260,7 @@ static struct attribute *node_dev_attrs[ &dev_attr_distance.attr, &dev_attr_vmstat.attr, &dev_attr_type.attr, + &dev_attr_peer_node.attr, NULL }; ATTRIBUTE_GROUPS(node_dev); --- linux.orig/include/linux/mmzone.h 2018-12-23 19:39:51.647261099 +0800 +++ linux/include/linux/mmzone.h 2018-12-23 19:39:51.643261112 +0800 @@ -713,6 +713,18 @@ typedef struct pglist_data { /* Per-node vmstats */ struct per_cpu_nodestat __percpu *per_cpu_nodestats; atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; + + /* + * Points to the nearest node in terms of latency + * E.g. peer of node 0 is node 2 per SLIT + * node distances: + * node 0 1 2 3 + * 0: 10 21 17 28 + * 1: 21 10 28 17 + * 2: 17 28 10 28 + * 3: 28 17 28 10 + */ + int peer_node; } pg_data_t; #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) --- linux.orig/mm/page_alloc.c 2018-12-23 19:39:51.647261099 +0800 +++ linux/mm/page_alloc.c 2018-12-23 19:39:51.643261112 +0800 @@ -6926,6 +6926,34 @@ static void check_for_memory(pg_data_t * } } +/* + * Return the nearest peer node in terms of *locality* + * E.g. peer of node 0 is node 2 per SLIT + * node distances: + * node 0 1 2 3 + * 0: 10 21 17 28 + * 1: 21 10 28 17 + * 2: 17 28 10 28 + * 3: 28 17 28 10 + */ +static int find_best_peer_node(int nid) +{ + int n, val; + int min_val = INT_MAX; + int peer = NUMA_NO_NODE; + + for_each_online_node(n) { + if (n == nid) + continue; + val = node_distance(nid, n); + if (val < min_val) { + min_val = val; + peer = n; + } + } + return peer; +} + /** * free_area_init_nodes - Initialise all pg_data_t and zone data * @max_zone_pfn: an array of max PFNs for each zone @@ -7012,6 +7040,7 @@ void __init free_area_init_nodes(unsigne if (pgdat->node_present_pages) node_set_state(nid, N_MEMORY); check_for_memory(pgdat, nid); + pgdat->peer_node = find_best_peer_node(nid); } } From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 631098E0003 for ; Wed, 26 Dec 2018 08:37:07 -0500 (EST) Received: by mail-pl1-f199.google.com with SMTP id 89so13992674ple.19 for ; Wed, 26 Dec 2018 05:37:07 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id c7si33395890pgg.339.2018.12.26.05.37.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 26 Dec 2018 05:37:06 -0800 (PST) Message-Id: <20181226133351.521151384@intel.com> Date: Wed, 26 Dec 2018 21:14:54 +0800 From: Fengguang Wu Subject: [RFC][PATCH v2 08/21] mm: introduce and export pgdat peer_node References: <20181226131446.330864849@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=0019-mm-Introduce-and-export-peer_node-for-pgdat.patch Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Linux Memory Management List , Fan Du , Fengguang Wu , kvm@vger.kernel.org, LKML , Yao Yuan , Peng Dong , Huang Ying , Liu Jingqi , Dong Eddie , Dave Hansen , Zhang Yi , Dan Williams From: Fan Du Each CPU socket can have 1 DRAM and 1 PMEM node, we call them "peer nodes". Migration between DRAM and PMEM will by default happen between peer nodes. It's a temp solution. In multiple memory layers, a node can have both promotion and demotion targets instead of a single peer node. User space may also be able to infer promotion/demotion targets based on future HMAT info. Signed-off-by: Fan Du Signed-off-by: Fengguang Wu --- drivers/base/node.c | 11 +++++++++++ include/linux/mmzone.h | 12 ++++++++++++ mm/page_alloc.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 52 insertions(+) --- linux.orig/drivers/base/node.c 2018-12-23 19:39:51.647261099 +0800 +++ linux/drivers/base/node.c 2018-12-23 19:39:51.643261112 +0800 @@ -242,6 +242,16 @@ static ssize_t type_show(struct device * } static DEVICE_ATTR(type, S_IRUGO, type_show, NULL); +static ssize_t peer_node_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int nid = dev->id; + struct pglist_data *pgdat = NODE_DATA(nid); + + return sprintf(buf, "%d\n", pgdat->peer_node); +} +static DEVICE_ATTR(peer_node, S_IRUGO, peer_node_show, NULL); + static struct attribute *node_dev_attrs[] = { &dev_attr_cpumap.attr, &dev_attr_cpulist.attr, @@ -250,6 +260,7 @@ static struct attribute *node_dev_attrs[ &dev_attr_distance.attr, &dev_attr_vmstat.attr, &dev_attr_type.attr, + &dev_attr_peer_node.attr, NULL }; ATTRIBUTE_GROUPS(node_dev); --- linux.orig/include/linux/mmzone.h 2018-12-23 19:39:51.647261099 +0800 +++ linux/include/linux/mmzone.h 2018-12-23 19:39:51.643261112 +0800 @@ -713,6 +713,18 @@ typedef struct pglist_data { /* Per-node vmstats */ struct per_cpu_nodestat __percpu *per_cpu_nodestats; atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; + + /* + * Points to the nearest node in terms of latency + * E.g. peer of node 0 is node 2 per SLIT + * node distances: + * node 0 1 2 3 + * 0: 10 21 17 28 + * 1: 21 10 28 17 + * 2: 17 28 10 28 + * 3: 28 17 28 10 + */ + int peer_node; } pg_data_t; #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) --- linux.orig/mm/page_alloc.c 2018-12-23 19:39:51.647261099 +0800 +++ linux/mm/page_alloc.c 2018-12-23 19:39:51.643261112 +0800 @@ -6926,6 +6926,34 @@ static void check_for_memory(pg_data_t * } } +/* + * Return the nearest peer node in terms of *locality* + * E.g. peer of node 0 is node 2 per SLIT + * node distances: + * node 0 1 2 3 + * 0: 10 21 17 28 + * 1: 21 10 28 17 + * 2: 17 28 10 28 + * 3: 28 17 28 10 + */ +static int find_best_peer_node(int nid) +{ + int n, val; + int min_val = INT_MAX; + int peer = NUMA_NO_NODE; + + for_each_online_node(n) { + if (n == nid) + continue; + val = node_distance(nid, n); + if (val < min_val) { + min_val = val; + peer = n; + } + } + return peer; +} + /** * free_area_init_nodes - Initialise all pg_data_t and zone data * @max_zone_pfn: an array of max PFNs for each zone @@ -7012,6 +7040,7 @@ void __init free_area_init_nodes(unsigne if (pgdat->node_present_pages) node_set_state(nid, N_MEMORY); check_for_memory(pgdat, nid); + pgdat->peer_node = find_best_peer_node(nid); } }