Commit 60a5a19e authored by Tang Chen's avatar Tang Chen Committed by Linus Torvalds
Browse files

memory-hotplug: remove sysfs file of node 



Introduce a new function try_offline_node() to remove sysfs file of node
when all memory sections of this node are removed.  If some memory
sections of this node are not removed, this function does nothing.

Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 815121d2

drivers/acpi/acpi_memhotplug.c

+6 −2
Original line number Diff line number Diff line
@@ -280,9 +280,11 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) 


static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)

{

	int result = 0;

	int result = 0, nid;

	struct acpi_memory_info *info, *n;



	nid = acpi_get_node(mem_device->device->handle);



	list_for_each_entry_safe(info, n, &mem_device->res_list, list) {

		if (info->failed)

			/* The kernel does not use this memory block */
@@ -295,7 +297,9 @@ static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) 
			 */

			return -EBUSY;



		result = remove_memory(info->start_addr, info->length);

		if (nid < 0)

			nid = memory_add_physaddr_to_nid(info->start_addr);

		result = remove_memory(nid, info->start_addr, info->length);

		if (result)

			return result;

include/linux/memory_hotplug.h

+1 −1
Original line number Diff line number Diff line
@@ -248,7 +248,7 @@ extern int arch_add_memory(int nid, u64 start, u64 size); 
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);

extern int offline_memory_block(struct memory_block *mem);

extern bool is_memblock_offlined(struct memory_block *mem);

extern int remove_memory(u64 start, u64 size);

extern int remove_memory(int nid, u64 start, u64 size);

extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,

								int nr_pages);

extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);

mm/memory_hotplug.c

+56 −2
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/suspend.h>

#include <linux/mm_inline.h>

#include <linux/firmware-map.h>

#include <linux/stop_machine.h>



#include <asm/tlbflush.h>
@@ -1679,7 +1680,58 @@ static int is_memblock_offlined_cb(struct memory_block *mem, void *arg) 
	return ret;

}



int __ref remove_memory(u64 start, u64 size)

static int check_cpu_on_node(void *data)

{

	struct pglist_data *pgdat = data;

	int cpu;



	for_each_present_cpu(cpu) {

		if (cpu_to_node(cpu) == pgdat->node_id)

			/*

			 * the cpu on this node isn't removed, and we can't

			 * offline this node.

			 */

			return -EBUSY;

	}



	return 0;

}



/* offline the node if all memory sections of this node are removed */

static void try_offline_node(int nid)

{

	unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;

	unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;

	unsigned long pfn;



	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {

		unsigned long section_nr = pfn_to_section_nr(pfn);



		if (!present_section_nr(section_nr))

			continue;



		if (pfn_to_nid(pfn) != nid)

			continue;



		/*

		 * some memory sections of this node are not removed, and we

		 * can't offline node now.

		 */

		return;

	}



	if (stop_machine(check_cpu_on_node, NODE_DATA(nid), NULL))

		return;



	/*

	 * all memory/cpu of this node are removed, we can offline this

	 * node now.

	 */

	node_set_offline(nid);

	unregister_one_node(nid);

}



int __ref remove_memory(int nid, u64 start, u64 size)

{

	unsigned long start_pfn, end_pfn;

	int ret = 0;
@@ -1734,6 +1786,8 @@ repeat: 


	arch_remove_memory(start, size);



	try_offline_node(nid);



	unlock_memory_hotplug();



	return 0;
@@ -1743,7 +1797,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) 
{

	return -EINVAL;

}

int remove_memory(u64 start, u64 size)

int remove_memory(int nid, u64 start, u64 size)

{

	return -EINVAL;

}

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