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Commit b3fb8724 authored by Liam Mark's avatar Liam Mark Committed by Gerrit - the friendly Code Review server
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drivers: base: expose amount allocated per block 



Add a new sysfs node called allocated_bytes to each memory block which
reports the amount of memory currently allocated from that block.

Userspace can then use the allocated_byes node to better evaluate the
potential cost of offlining an individual block since all the allocated
memory in the block will need to be migrated when the block is offlined.

Change-Id: I520de2dd56e4562a65c48e38edb1236a8cbce5fd
Signed-off-by: default avatarLiam Mark <lmark@codeaurora.org>
parent 06f4a1fd

drivers/base/memory.c

+55 −0
Original line number Diff line number Diff line
@@ -447,10 +447,62 @@ static ssize_t show_valid_zones(struct device *dev, 
static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);

#endif



#ifdef CONFIG_MEMORY_HOTPLUG

static int count_num_free_block_pages(struct zone *zone, int bid)

{

	int order, type;

	unsigned long freecount = 0;

	unsigned long flags;



	spin_lock_irqsave(&zone->lock, flags);

	for (type = 0; type < MIGRATE_TYPES; type++) {

		for (order = 0; order < MAX_ORDER; ++order) {

			struct free_area *area;

			struct page *page;



			area = &(zone->free_area[order]);

			list_for_each_entry(page, &area->free_list[type], lru) {

				unsigned long pfn = page_to_pfn(page);

				int section_nr = pfn_to_section_nr(pfn);



				if (bid == base_memory_block_id(section_nr))

					freecount += (1 << order);

			}



		}

	}

	spin_unlock_irqrestore(&zone->lock, flags);



	return freecount;

}



static ssize_t show_allocated_bytes(struct device *dev,

			struct device_attribute *attr, char *buf)

{

	struct memory_block *mem = to_memory_block(dev);

	int block_id, free_pages;

	struct zone *movable_zone =

		&NODE_DATA(numa_node_id())->node_zones[ZONE_MOVABLE];

	unsigned long used, block_sz = get_memory_block_size();



	if (mem->state != MEM_ONLINE)

		return snprintf(buf, 100, "0\n");



	block_id = base_memory_block_id(mem->start_section_nr);

	free_pages = count_num_free_block_pages(movable_zone, block_id);

	used =  block_sz - (free_pages * PAGE_SIZE);



	return snprintf(buf, 100, "%lu\n", used);

}

#endif



static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);

static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state);

static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL);

static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL);

#ifdef CONFIG_MEMORY_HOTPLUG

static DEVICE_ATTR(allocated_bytes, 0444, show_allocated_bytes, NULL);

#endif



/*

 * Block size attribute stuff
@@ -655,6 +707,9 @@ static struct attribute *memory_memblk_attrs[] = { 
	&dev_attr_removable.attr,

#ifdef CONFIG_MEMORY_HOTREMOVE

	&dev_attr_valid_zones.attr,

#endif

#ifdef CONFIG_MEMORY_HOTPLUG

	&dev_attr_allocated_bytes.attr,

#endif

	NULL

};