hotplug memory remove: generic __remove_pages() support (ea01ea93) · Commits · e / devices / android_kernel_teracube_emerald

include/linux/memory_hotplug.h

+5 −1

Original line number	Original line	Diff line number	Diff line
	@@ -8,6 +8,7 @@
	struct page;		struct page;
	struct zone;		struct zone;
	struct pglist_data;		struct pglist_data;
			struct mem_section;

	#ifdef CONFIG_MEMORY_HOTPLUG		#ifdef CONFIG_MEMORY_HOTPLUG
	/*		/*
	@@ -64,9 +65,11 @@ extern int offline_pages(unsigned long, unsigned long, unsigned long);
	/* reasonably generic interface to expand the physical pages in a zone */		/* reasonably generic interface to expand the physical pages in a zone */
	extern int __add_pages(struct zone *zone, unsigned long start_pfn,		extern int __add_pages(struct zone *zone, unsigned long start_pfn,
	unsigned long nr_pages);		unsigned long nr_pages);
			extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
			unsigned long nr_pages);

	/*		/*
	* Walk thorugh all memory which is registered as resource.		* Walk through all memory which is registered as resource.
	* arg is (start_pfn, nr_pages, private_arg_pointer)		* arg is (start_pfn, nr_pages, private_arg_pointer)
	*/		*/
	extern int walk_memory_resource(unsigned long start_pfn,		extern int walk_memory_resource(unsigned long start_pfn,
	@@ -176,5 +179,6 @@ extern int arch_add_memory(int nid, u64 start, u64 size);
	extern int remove_memory(u64 start, u64 size);		extern int remove_memory(u64 start, u64 size);
	extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,		extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
	int nr_pages);		int nr_pages);
			extern void sparse_remove_one_section(struct zone zone, struct mem_section ms);

	#endif /* __LINUX_MEMORY_HOTPLUG_H */		#endif /* __LINUX_MEMORY_HOTPLUG_H */

mm/memory_hotplug.c

+55 −0

Original line number	Original line	Diff line number	Diff line
	@@ -101,6 +101,25 @@ static int __add_section(struct zone *zone, unsigned long phys_start_pfn)
	return register_new_memory(__pfn_to_section(phys_start_pfn));		return register_new_memory(__pfn_to_section(phys_start_pfn));
	}		}

			static int __remove_section(struct zone zone, struct mem_section ms)
			{
			unsigned long flags;
			struct pglist_data *pgdat = zone->zone_pgdat;
			int ret = -EINVAL;

			if (!valid_section(ms))
			return ret;

			ret = unregister_memory_section(ms);
			if (ret)
			return ret;

			pgdat_resize_lock(pgdat, &flags);
			sparse_remove_one_section(zone, ms);
			pgdat_resize_unlock(pgdat, &flags);
			return 0;
			}

	/*		/*
	* Reasonably generic function for adding memory. It is		* Reasonably generic function for adding memory. It is
	* expected that archs that support memory hotplug will		* expected that archs that support memory hotplug will
	@@ -134,6 +153,42 @@ int __add_pages(struct zone *zone, unsigned long phys_start_pfn,
	}		}
	EXPORT_SYMBOL_GPL(__add_pages);		EXPORT_SYMBOL_GPL(__add_pages);

			/**
			* __remove_pages() - remove sections of pages from a zone
			* @zone: zone from which pages need to be removed
			* @phys_start_pfn: starting pageframe (must be aligned to start of a section)
			* @nr_pages: number of pages to remove (must be multiple of section size)
			*
			* Generic helper function to remove section mappings and sysfs entries
			* for the section of the memory we are removing. Caller needs to make
			* sure that pages are marked reserved and zones are adjust properly by
			* calling offline_pages().
			*/
			int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
			unsigned long nr_pages)
			{
			unsigned long i, ret = 0;
			int sections_to_remove;

			/*
			* We can only remove entire sections
			*/
			BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK);
			BUG_ON(nr_pages % PAGES_PER_SECTION);

			release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE);

			sections_to_remove = nr_pages / PAGES_PER_SECTION;
			for (i = 0; i < sections_to_remove; i++) {
			unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
			ret = __remove_section(zone, __pfn_to_section(pfn));
			if (ret)
			break;
			}
			return ret;
			}
			EXPORT_SYMBOL_GPL(__remove_pages);

	static void grow_zone_span(struct zone *zone,		static void grow_zone_span(struct zone *zone,
	unsigned long start_pfn, unsigned long end_pfn)		unsigned long start_pfn, unsigned long end_pfn)
	{		{

mm/sparse.c

+42 −3

Original line number	Original line	Diff line number	Diff line
	@@ -208,12 +208,13 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p
	}		}

	/*		/*
	* We need this if we ever free the mem_maps. While not implemented yet,		* Decode mem_map from the coded memmap
	* this function is included for parity with its sibling.
	*/		*/
	static __attribute((unused))		static
	struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)		struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
	{		{
			/* mask off the extra low bits of information */
			coded_mem_map &= SECTION_MAP_MASK;
	return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);		return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
	}		}

	@@ -404,6 +405,28 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
	}		}
	#endif /* CONFIG_SPARSEMEM_VMEMMAP */		#endif /* CONFIG_SPARSEMEM_VMEMMAP */

			static void free_section_usemap(struct page memmap, unsigned long usemap)
			{
			if (!usemap)
			return;

			/*
			* Check to see if allocation came from hot-plug-add
			*/
			if (PageSlab(virt_to_page(usemap))) {
			kfree(usemap);
			if (memmap)
			__kfree_section_memmap(memmap, PAGES_PER_SECTION);
			return;
			}

			/*
			* TODO: Allocations came from bootmem - how do I free up ?
			*/
			printk(KERN_WARNING "Not freeing up allocations from bootmem "
			"- leaking memory\n");
			}

	/*		/*
	* returns the number of sections whose mem_maps were properly		* returns the number of sections whose mem_maps were properly
	* set. If this is <=0, then that means that the passed-in		* set. If this is <=0, then that means that the passed-in
	@@ -456,4 +479,20 @@ int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
	}		}
	return ret;		return ret;
	}		}

			void sparse_remove_one_section(struct zone zone, struct mem_section ms)
			{
			struct page *memmap = NULL;
			unsigned long *usemap = NULL;

			if (ms->section_mem_map) {
			usemap = ms->pageblock_flags;
			memmap = sparse_decode_mem_map(ms->section_mem_map,
			__section_nr(ms));
			ms->section_mem_map = 0;
			ms->pageblock_flags = NULL;
			}

			free_section_usemap(memmap, usemap);
			}
	#endif		#endif