14392fd329
CONFIG_DEBUG_PER_CPU_MAPS may return NUMA_NO_NODE when an early_cpu_to_node() mapping hasn't been initialized. In such a case, it emits a warning and continues without an issue but callers may try to use the return value to index into an array. We can catch those errors and fail silently since a warning has already been emitted. No current user of numa_add_cpu() requires this error checking to avoid a crash, but it's better to be proactive in case a future user happens to have a bug and a user tries to diagnose it with CONFIG_DEBUG_PER_CPU_MAPS. Reported-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <alpine.DEB.2.00.1102071407250.7812@chino.kir.corp.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
290 lines
6.5 KiB
C
290 lines
6.5 KiB
C
/* Common code for 32 and 64-bit NUMA */
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#include <linux/topology.h>
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#include <linux/module.h>
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#include <linux/bootmem.h>
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#include <asm/numa.h>
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#include <asm/acpi.h>
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int __initdata numa_off;
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static __init int numa_setup(char *opt)
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{
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if (!opt)
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return -EINVAL;
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if (!strncmp(opt, "off", 3))
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numa_off = 1;
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#ifdef CONFIG_NUMA_EMU
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if (!strncmp(opt, "fake=", 5))
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numa_emu_cmdline(opt + 5);
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#endif
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#ifdef CONFIG_ACPI_NUMA
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if (!strncmp(opt, "noacpi", 6))
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acpi_numa = -1;
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#endif
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return 0;
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}
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early_param("numa", numa_setup);
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/*
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* apicid, cpu, node mappings
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*/
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s16 __apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
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[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
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};
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cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
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EXPORT_SYMBOL(node_to_cpumask_map);
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/*
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* Map cpu index to node index
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*/
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DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
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EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
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void __cpuinit numa_set_node(int cpu, int node)
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{
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int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
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/* early setting, no percpu area yet */
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if (cpu_to_node_map) {
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cpu_to_node_map[cpu] = node;
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return;
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}
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#ifdef CONFIG_DEBUG_PER_CPU_MAPS
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if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
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printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
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dump_stack();
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return;
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}
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#endif
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per_cpu(x86_cpu_to_node_map, cpu) = node;
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if (node != NUMA_NO_NODE)
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set_cpu_numa_node(cpu, node);
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}
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void __cpuinit numa_clear_node(int cpu)
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{
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numa_set_node(cpu, NUMA_NO_NODE);
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}
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/*
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* Allocate node_to_cpumask_map based on number of available nodes
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* Requires node_possible_map to be valid.
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*
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* Note: node_to_cpumask() is not valid until after this is done.
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* (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
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*/
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void __init setup_node_to_cpumask_map(void)
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{
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unsigned int node, num = 0;
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/* setup nr_node_ids if not done yet */
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if (nr_node_ids == MAX_NUMNODES) {
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for_each_node_mask(node, node_possible_map)
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num = node;
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nr_node_ids = num + 1;
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}
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/* allocate the map */
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for (node = 0; node < nr_node_ids; node++)
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alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
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/* cpumask_of_node() will now work */
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pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
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}
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/*
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* There are unfortunately some poorly designed mainboards around that
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* only connect memory to a single CPU. This breaks the 1:1 cpu->node
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* mapping. To avoid this fill in the mapping for all possible CPUs,
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* as the number of CPUs is not known yet. We round robin the existing
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* nodes.
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*/
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void __init numa_init_array(void)
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{
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int rr, i;
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rr = first_node(node_online_map);
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for (i = 0; i < nr_cpu_ids; i++) {
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if (early_cpu_to_node(i) != NUMA_NO_NODE)
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continue;
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numa_set_node(i, rr);
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rr = next_node(rr, node_online_map);
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if (rr == MAX_NUMNODES)
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rr = first_node(node_online_map);
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}
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}
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static __init int find_near_online_node(int node)
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{
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int n, val;
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int min_val = INT_MAX;
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int best_node = -1;
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for_each_online_node(n) {
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val = node_distance(node, n);
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if (val < min_val) {
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min_val = val;
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best_node = n;
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}
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}
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return best_node;
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}
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/*
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* Setup early cpu_to_node.
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*
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* Populate cpu_to_node[] only if x86_cpu_to_apicid[],
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* and apicid_to_node[] tables have valid entries for a CPU.
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* This means we skip cpu_to_node[] initialisation for NUMA
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* emulation and faking node case (when running a kernel compiled
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* for NUMA on a non NUMA box), which is OK as cpu_to_node[]
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* is already initialized in a round robin manner at numa_init_array,
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* prior to this call, and this initialization is good enough
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* for the fake NUMA cases.
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*
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* Called before the per_cpu areas are setup.
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*/
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void __init init_cpu_to_node(void)
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{
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int cpu;
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u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
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BUG_ON(cpu_to_apicid == NULL);
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for_each_possible_cpu(cpu) {
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int node = numa_cpu_node(cpu);
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if (node == NUMA_NO_NODE)
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continue;
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if (!node_online(node))
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node = find_near_online_node(node);
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numa_set_node(cpu, node);
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}
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}
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#ifndef CONFIG_DEBUG_PER_CPU_MAPS
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# ifndef CONFIG_NUMA_EMU
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void __cpuinit numa_add_cpu(int cpu)
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{
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cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
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}
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void __cpuinit numa_remove_cpu(int cpu)
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{
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cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
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}
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# endif /* !CONFIG_NUMA_EMU */
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#else /* !CONFIG_DEBUG_PER_CPU_MAPS */
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int __cpu_to_node(int cpu)
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{
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if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
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printk(KERN_WARNING
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"cpu_to_node(%d): usage too early!\n", cpu);
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dump_stack();
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return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
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}
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return per_cpu(x86_cpu_to_node_map, cpu);
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}
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EXPORT_SYMBOL(__cpu_to_node);
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/*
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* Same function as cpu_to_node() but used if called before the
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* per_cpu areas are setup.
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*/
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int early_cpu_to_node(int cpu)
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{
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if (early_per_cpu_ptr(x86_cpu_to_node_map))
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return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
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if (!cpu_possible(cpu)) {
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printk(KERN_WARNING
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"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
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dump_stack();
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return NUMA_NO_NODE;
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}
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return per_cpu(x86_cpu_to_node_map, cpu);
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}
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struct cpumask __cpuinit *debug_cpumask_set_cpu(int cpu, int enable)
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{
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int node = early_cpu_to_node(cpu);
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struct cpumask *mask;
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char buf[64];
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if (node == NUMA_NO_NODE) {
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/* early_cpu_to_node() already emits a warning and trace */
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return NULL;
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}
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mask = node_to_cpumask_map[node];
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if (!mask) {
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pr_err("node_to_cpumask_map[%i] NULL\n", node);
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dump_stack();
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return NULL;
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}
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cpulist_scnprintf(buf, sizeof(buf), mask);
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printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
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enable ? "numa_add_cpu" : "numa_remove_cpu",
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cpu, node, buf);
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return mask;
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}
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# ifndef CONFIG_NUMA_EMU
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static void __cpuinit numa_set_cpumask(int cpu, int enable)
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{
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struct cpumask *mask;
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mask = debug_cpumask_set_cpu(cpu, enable);
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if (!mask)
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return;
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if (enable)
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cpumask_set_cpu(cpu, mask);
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else
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cpumask_clear_cpu(cpu, mask);
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}
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void __cpuinit numa_add_cpu(int cpu)
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{
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numa_set_cpumask(cpu, 1);
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}
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void __cpuinit numa_remove_cpu(int cpu)
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{
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numa_set_cpumask(cpu, 0);
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}
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# endif /* !CONFIG_NUMA_EMU */
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/*
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* Returns a pointer to the bitmask of CPUs on Node 'node'.
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*/
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const struct cpumask *cpumask_of_node(int node)
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{
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if (node >= nr_node_ids) {
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printk(KERN_WARNING
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"cpumask_of_node(%d): node > nr_node_ids(%d)\n",
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node, nr_node_ids);
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dump_stack();
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return cpu_none_mask;
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}
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if (node_to_cpumask_map[node] == NULL) {
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printk(KERN_WARNING
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"cpumask_of_node(%d): no node_to_cpumask_map!\n",
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node);
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dump_stack();
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return cpu_online_mask;
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}
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return node_to_cpumask_map[node];
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}
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EXPORT_SYMBOL(cpumask_of_node);
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#endif /* !CONFIG_DEBUG_PER_CPU_MAPS */
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