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From: Jiang Liu <jiang.liu@linux.intel.com>
To: "Andrew Morton" <akpm@linux-foundation.org>,
	"Mel Gorman" <mgorman@suse.de>,
	"David Rientjes" <rientjes@google.com>,
	"Mike Galbraith" <umgwanakikbuti@gmail.com>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	"Tang Chen" <tangchen@cn.fujitsu.com>,
	"Tejun Heo" <tj@kernel.org>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Ingo Molnar" <mingo@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	"Len Brown" <len.brown@intel.com>, "Pavel Machek" <pavel@ucw.cz>,
	"Borislav Petkov" <bp@alien8.de>,
	"Andy Lutomirski" <luto@amacapital.net>,
	"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"Jan H. Schönherr" <jschoenh@amazon.de>,
	"Igor Mammedov" <imammedo@redhat.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	"Xishi Qiu" <qiuxishi@huawei.com>,
	"Jiang Liu" <jiang.liu@linux.intel.com>,
	"Luiz Capitulino" <lcapitulino@redhat.com>,
	"Dave Young" <dyoung@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>,
	linux-mm@kvack.org, linux-hotplug@vger.kernel.org,
	linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
	linux-pm@vger.kernel.org
Subject: [Patch V3 9/9] mm, x86: Enable memoryless node support to better support CPU/memory hotplug
Date: Mon, 17 Aug 2015 11:19:06 +0800	[thread overview]
Message-ID: <1439781546-7217-10-git-send-email-jiang.liu@linux.intel.com> (raw)
In-Reply-To: <1439781546-7217-1-git-send-email-jiang.liu@linux.intel.com>

With current implementation, all CPUs within a NUMA node will be
assocaited with another NUMA node if the node has no memory installed.

For example, on a four-node system, CPUs on node 2 and 3 are associated
with node 0 when are no memory install on node 2 and 3, which may
confuse users.
root@bkd01sdp:~# numactl --hardware
available: 2 nodes (0-1)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
node 0 size: 15602 MB
node 0 free: 15014 MB
node 1 cpus: 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
node 1 size: 15985 MB
node 1 free: 15686 MB
node distances:
node   0   1
  0:  10  21
  1:  21  10

To be worse, the CPU affinity relationship won't get fixed even after
memory has been added to those nodes. After memory hot-addition to
node 2, CPUs on node 2 are still associated with node 0. This may cause
sub-optimal performance.
root@bkd01sdp:/sys/devices/system/node/node2# numactl --hardware
available: 3 nodes (0-2)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
node 0 size: 15602 MB
node 0 free: 14743 MB
node 1 cpus: 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
node 1 size: 15985 MB
node 1 free: 15715 MB
node 2 cpus:
node 2 size: 128 MB
node 2 free: 128 MB
node distances:
node   0   1   2
  0:  10  21  21
  1:  21  10  21
  2:  21  21  10

With support of memoryless node enabled, it will correctly report system
hardware topology for nodes without memory installed.
root@bkd01sdp:~# numactl --hardware
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74
node 0 size: 15725 MB
node 0 free: 15129 MB
node 1 cpus: 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
node 1 size: 15862 MB
node 1 free: 15627 MB
node 2 cpus: 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104
node 2 size: 0 MB
node 2 free: 0 MB
node 3 cpus: 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
node 3 size: 0 MB
node 3 free: 0 MB
node distances:
node   0   1   2   3
  0:  10  21  21  21
  1:  21  10  21  21
  2:  21  21  10  21
  3:  21  21  21  10

With memoryless node enabled, CPUs are correctly associated with node 2
after memory hot-addition to node 2.
root@bkd01sdp:/sys/devices/system/node/node2# numactl --hardware
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74
node 0 size: 15725 MB
node 0 free: 14872 MB
node 1 cpus: 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
node 1 size: 15862 MB
node 1 free: 15641 MB
node 2 cpus: 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104
node 2 size: 128 MB
node 2 free: 127 MB
node 3 cpus: 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
node 3 size: 0 MB
node 3 free: 0 MB
node distances:
node   0   1   2   3
  0:  10  21  21  21
  1:  21  10  21  21
  2:  21  21  10  21
  3:  21  21  21  10

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 arch/x86/Kconfig            |    3 +++
 arch/x86/kernel/acpi/boot.c |    4 +++-
 arch/x86/kernel/smpboot.c   |    2 ++
 arch/x86/mm/numa.c          |   49 +++++++++++++++++++++++++++++++------------
 4 files changed, 44 insertions(+), 14 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b3a1a5d77d92..5d7ad70ace0d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2069,6 +2069,9 @@ config USE_PERCPU_NUMA_NODE_ID
 	def_bool y
 	depends on NUMA
 
+config HAVE_MEMORYLESS_NODES
+	def_bool NUMA
+
 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 	def_bool y
 	depends on X86_64 || X86_PAE
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 07930e1d2fe9..3403f1f0f28d 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -711,6 +711,7 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 		}
 		set_apicid_to_node(physid, nid);
 		numa_set_node(cpu, nid);
+		set_cpu_numa_mem(cpu, local_memory_node(nid));
 	}
 #endif
 }
@@ -743,9 +744,10 @@ int acpi_unmap_cpu(int cpu)
 {
 #ifdef CONFIG_ACPI_NUMA
 	set_apicid_to_node(per_cpu(x86_cpu_to_apicid, cpu), NUMA_NO_NODE);
+	set_cpu_numa_mem(cpu, NUMA_NO_NODE);
 #endif
 
-	per_cpu(x86_cpu_to_apicid, cpu) = -1;
+	per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
 	set_cpu_present(cpu, false);
 	num_processors--;
 
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index b1f3ed9c7a9e..aeec91ac6fd4 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -162,6 +162,8 @@ static void smp_callin(void)
 	 */
 	phys_id = read_apic_id();
 
+	set_numa_mem(local_memory_node(cpu_to_node(cpuid)));
+
 	/*
 	 * the boot CPU has finished the init stage and is spinning
 	 * on callin_map until we finish. We are free to set up this
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 08860bdf5744..f2a4e23bd14d 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -22,6 +22,7 @@
 
 int __initdata numa_off;
 nodemask_t numa_nodes_parsed __initdata;
+static nodemask_t numa_nodes_empty __initdata;
 
 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
 EXPORT_SYMBOL(node_data);
@@ -560,17 +561,16 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
 			end = max(mi->blk[i].end, end);
 		}
 
-		if (start >= end)
-			continue;
-
 		/*
 		 * Don't confuse VM with a node that doesn't have the
 		 * minimum amount of memory:
 		 */
-		if (end && (end - start) < NODE_MIN_SIZE)
-			continue;
-
-		alloc_node_data(nid);
+		if (start < end && (end - start) >= NODE_MIN_SIZE) {
+			alloc_node_data(nid);
+		} else if (IS_ENABLED(CONFIG_HAVE_MEMORYLESS_NODES)) {
+			alloc_node_data(nid);
+			node_set(nid, numa_nodes_empty);
+		}
 	}
 
 	/* Dump memblock with node info and return. */
@@ -587,14 +587,18 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
  */
 static void __init numa_init_array(void)
 {
-	int rr, i;
+	int i, rr = MAX_NUMNODES;
 
-	rr = first_node(node_online_map);
 	for (i = 0; i < nr_cpu_ids; i++) {
+		/* Search for an onlined node with memory */
+		do {
+			if (rr != MAX_NUMNODES)
+				rr = next_node(rr, node_online_map);
+			if (rr == MAX_NUMNODES)
+				rr = first_node(node_online_map);
+		} while (node_isset(rr, numa_nodes_empty));
+
 		numa_set_node(i, rr);
-		rr = next_node(rr, node_online_map);
-		if (rr == MAX_NUMNODES)
-			rr = first_node(node_online_map);
 	}
 }
 
@@ -696,9 +700,12 @@ static __init int find_near_online_node(int node)
 {
 	int n, val;
 	int min_val = INT_MAX;
-	int best_node = -1;
+	int best_node = NUMA_NO_NODE;
 
 	for_each_online_node(n) {
+		if (node_isset(n, numa_nodes_empty))
+			continue;
+
 		val = node_distance(node, n);
 
 		if (val < min_val) {
@@ -739,6 +746,22 @@ void __init init_cpu_to_node(void)
 		if (!node_online(node))
 			node = find_near_online_node(node);
 		numa_set_node(cpu, node);
+		if (node_spanned_pages(node))
+			set_cpu_numa_mem(cpu, node);
+		if (IS_ENABLED(CONFIG_HAVE_MEMORYLESS_NODES))
+			node_clear(node, numa_nodes_empty);
+	}
+
+	/* Destroy empty nodes */
+	if (IS_ENABLED(CONFIG_HAVE_MEMORYLESS_NODES)) {
+		int nid;
+		const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
+
+		for_each_node_mask(nid, numa_nodes_empty) {
+			node_set_offline(nid);
+			memblock_free(__pa(node_data[nid]), nd_size);
+			node_data[nid] = NULL;
+		}
 	}
 }
 
-- 
1.7.10.4

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  parent reply	other threads:[~2015-08-17  3:16 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-17  3:18 [Patch V3 0/9] Enable memoryless node support for x86 Jiang Liu
2015-08-17  3:18 ` [Patch V3 1/9] x86, NUMA, ACPI: Online node earlier when doing CPU hot-addition Jiang Liu
2015-08-17  3:18 ` [Patch V3 2/9] kernel/profile.c: Replace cpu_to_mem() with cpu_to_node() Jiang Liu
2015-08-18  0:31   ` David Rientjes
2015-08-19  7:18     ` Jiang Liu
2015-08-20  0:00       ` David Rientjes
2015-10-09  2:35         ` Jiang Liu
2015-08-17  3:19 ` [Patch V3 3/9] sgi-xp: Replace cpu_to_node() with cpu_to_mem() to support memoryless node Jiang Liu
2015-08-18  0:25   ` David Rientjes
2015-08-19  8:20     ` Jiang Liu
2015-08-20  0:02       ` David Rientjes
2015-08-20  6:36         ` Jiang Liu
2015-10-09  5:04           ` Jiang Liu
2015-08-19 11:52   ` Robin Holt
2015-08-19 12:45     ` Jiang Liu
2015-08-17  3:19 ` [Patch V3 4/9] openvswitch: " Jiang Liu
2015-08-18  0:14   ` Pravin Shelar
2015-08-17  3:19 ` [Patch V3 5/9] i40e: Use numa_mem_id() to better " Jiang Liu
2015-08-18  0:35   ` David Rientjes
2015-08-19 22:38   ` [Intel-wired-lan] " Patil, Kiran
2015-08-20  0:18     ` David Rientjes
2015-10-08 20:20       ` Andrew Morton
2015-10-09  5:52         ` Jiang Liu
2015-10-09  9:08           ` Kamezawa Hiroyuki
2015-10-09  9:25             ` Jiang Liu
2015-08-17  3:19 ` [Patch V3 6/9] i40evf: " Jiang Liu
2015-08-17 19:03   ` [Intel-wired-lan] " Patil, Kiran
2015-08-18 21:34     ` Jeff Kirsher
2015-08-17  3:19 ` [Patch V3 7/9] x86, numa: Kill useless code to improve code readability Jiang Liu
2015-08-17  3:19 ` [Patch V3 8/9] mm: Update _mem_id_[] for every possible CPU when memory configuration changes Jiang Liu
2015-08-17  3:19 ` Jiang Liu [this message]
2015-08-18  6:11   ` [Patch V3 9/9] mm, x86: Enable memoryless node support to better support CPU/memory hotplug Tang Chen
2015-08-18  6:59     ` Jiang Liu
2015-08-18 11:28       ` Tang Chen
2015-08-18  7:31   ` Ingo Molnar
2015-08-17 21:35 ` [Patch V3 0/9] Enable memoryless node support for x86 Andrew Morton
2015-08-18 10:02 ` Tang Chen
2015-08-19  8:09   ` Jiang Liu

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