mm: remove managed_page_count_lock spinlock

	 * Write access to present_pages at runtime should be protected by

	 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of

	 * present_pages should get_online_mems() to get a stable value.

	 *

	 * Read access to managed_pages should be safe because it's unsigned

	 * long. Write access to zone->managed_pages and totalram_pages are

	 * protected by managed_page_count_lock at runtime. Idealy only

	 * adjust_managed_page_count() should be used instead of directly

	 * touching zone->managed_pages and totalram_pages.

	 */

	atomic_long_t		managed_pages;

	unsigned long		spanned_pages;

};

EXPORT_SYMBOL(node_states);

/* Protect totalram_pages and zone->managed_pages */

static DEFINE_SPINLOCK(managed_page_count_lock);

atomic_long_t _totalram_pages __read_mostly;

EXPORT_SYMBOL(_totalram_pages);

unsigned long totalreserve_pages __read_mostly;

void adjust_managed_page_count(struct page *page, long count)

{

	spin_lock(&managed_page_count_lock);

	atomic_long_add(count, &page_zone(page)->managed_pages);

	totalram_pages_add(count);

#ifdef CONFIG_HIGHMEM

	if (PageHighMem(page))

		totalhigh_pages_add(count);

#endif

	spin_unlock(&managed_page_count_lock);

}

EXPORT_SYMBOL(adjust_managed_page_count);