Commit e13fe869 authored by Wen Congyang's avatar Wen Congyang Committed by Linus Torvalds
Browse files

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: default avatarWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 76bba142

arch/x86/include/asm/numa.h

+2 −2
Original line number Diff line number Diff line
@@ -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);

arch/x86/mm/numa.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

}

mm/memory_hotplug.c

+29 −1
Original line number Diff line number Diff line
@@ -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;



	/*

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