From e13fe8695c57fed678877a9f3f8e99fc637ff4fb Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Fri, 22 Feb 2013 16:33:31 -0800 Subject: [PATCH] cpu-hotplug,memory-hotplug: clear cpu_to_node() when offlining the node When the node is offlined, there is no memory/cpu on the node. If a sleep task runs on a cpu of this node, it will be migrated to the cpu on the other node. So we can clear cpu-to-node mapping. [akpm@linux-foundation.org: numa_clear_node() and numa_set_node() can no longer be __cpuinit] Signed-off-by: Wen Congyang Signed-off-by: Tang Chen Cc: Yasuaki Ishimatsu Cc: David Rientjes Cc: Jiang Liu Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Mel Gorman Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/include/asm/numa.h | 4 ++-- arch/x86/mm/numa.c | 4 ++-- mm/memory_hotplug.c | 30 +++++++++++++++++++++++++++++- 3 files changed, 33 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h index 52560a2038e1..1b99ee5c9f00 100644 --- a/arch/x86/include/asm/numa.h +++ b/arch/x86/include/asm/numa.h @@ -57,8 +57,8 @@ static inline int numa_cpu_node(int cpu) #endif #ifdef CONFIG_NUMA -extern void __cpuinit numa_set_node(int cpu, int node); -extern void __cpuinit numa_clear_node(int cpu); +extern void numa_set_node(int cpu, int node); +extern void numa_clear_node(int cpu); extern void __init init_cpu_to_node(void); extern void __cpuinit numa_add_cpu(int cpu); extern void __cpuinit numa_remove_cpu(int cpu); diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index f22680bf69ec..a713d081b59c 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -78,7 +78,7 @@ EXPORT_SYMBOL(node_to_cpumask_map); DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE); EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map); -void __cpuinit numa_set_node(int cpu, int node) +void numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); @@ -101,7 +101,7 @@ void __cpuinit numa_set_node(int cpu, int node) set_cpu_numa_node(cpu, node); } -void __cpuinit numa_clear_node(int cpu) +void numa_clear_node(int cpu) { numa_set_node(cpu, NUMA_NO_NODE); } diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 17e1447077ab..a9072a16a160 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1705,6 +1705,34 @@ static int check_cpu_on_node(void *data) return 0; } +static void unmap_cpu_on_node(void *data) +{ +#ifdef CONFIG_ACPI_NUMA + struct pglist_data *pgdat = data; + int cpu; + + for_each_possible_cpu(cpu) + if (cpu_to_node(cpu) == pgdat->node_id) + numa_clear_node(cpu); +#endif +} + +static int check_and_unmap_cpu_on_node(void *data) +{ + int ret = check_cpu_on_node(data); + + if (ret) + return ret; + + /* + * the node will be offlined when we come here, so we can clear + * the cpu_to_node() now. + */ + + unmap_cpu_on_node(data); + return 0; +} + /* offline the node if all memory sections of this node are removed */ void try_offline_node(int nid) { @@ -1731,7 +1759,7 @@ void try_offline_node(int nid) return; } - if (stop_machine(check_cpu_on_node, pgdat, NULL)) + if (stop_machine(check_and_unmap_cpu_on_node, pgdat, NULL)) return; /* -- 2.20.1