Commit 24d335ca authored by Wen Congyang's avatar Wen Congyang Committed by Linus Torvalds
Browse files

memory-hotplug: introduce new arch_remove_memory() for removing page table 



For removing memory, we need to remove page tables.  But it depends on
architecture.  So the patch introduce arch_remove_memory() for removing
page table.  Now it only calls __remove_pages().

Note: __remove_pages() for some archtecuture is not implemented
      (I don't know how to implement it for s390).

Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.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 46c66c4b

arch/ia64/mm/init.c

+18 −0
Original line number Diff line number Diff line
@@ -688,6 +688,24 @@ int arch_add_memory(int nid, u64 start, u64 size) 


	return ret;

}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(u64 start, u64 size)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;

	int ret;



	zone = page_zone(pfn_to_page(start_pfn));

	ret = __remove_pages(zone, start_pfn, nr_pages);

	if (ret)

		pr_warn("%s: Problem encountered in __remove_pages() as"

			" ret=%d\n", __func__,  ret);



	return ret;

}

#endif

#endif



/*

arch/powerpc/mm/mem.c

+12 −0
Original line number Diff line number Diff line
@@ -133,6 +133,18 @@ int arch_add_memory(int nid, u64 start, u64 size) 


	return __add_pages(nid, zone, start_pfn, nr_pages);

}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(u64 start, u64 size)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;



	zone = page_zone(pfn_to_page(start_pfn));

	return __remove_pages(zone, start_pfn, nr_pages);

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */



/*

arch/s390/mm/init.c

+12 −0
Original line number Diff line number Diff line
@@ -228,4 +228,16 @@ int arch_add_memory(int nid, u64 start, u64 size) 
		vmem_remove_mapping(start, size);

	return rc;

}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(u64 start, u64 size)

{

	/*

	 * There is no hardware or firmware interface which could trigger a

	 * hot memory remove on s390. So there is nothing that needs to be

	 * implemented.

	 */

	return -EBUSY;

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */

arch/sh/mm/init.c

+17 −0
Original line number Diff line number Diff line
@@ -558,4 +558,21 @@ int memory_add_physaddr_to_nid(u64 addr) 
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);

#endif



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(u64 start, u64 size)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	struct zone *zone;

	int ret;



	zone = page_zone(pfn_to_page(start_pfn));

	ret = __remove_pages(zone, start_pfn, nr_pages);

	if (unlikely(ret))

		pr_warn("%s: Failed, __remove_pages() == %d\n", __func__,

			ret);



	return ret;

}

#endif

#endif /* CONFIG_MEMORY_HOTPLUG */

arch/tile/mm/init.c

+8 −0
Original line number Diff line number Diff line
@@ -935,6 +935,14 @@ int remove_memory(u64 start, u64 size) 
{

	return -EINVAL;

}



#ifdef CONFIG_MEMORY_HOTREMOVE

int arch_remove_memory(u64 start, u64 size)

{

	/* TODO */

	return -EBUSY;

}

#endif

#endif



struct kmem_cache *pgd_cache;

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