mm/page_alloc: add __free_pages() documentation (7f194fbb) · Commits · 戴 / test

mm/page_alloc.c

+20 −0

Original line number	Diff line number	Diff line
		@@ -5043,6 +5043,26 @@ static inline void free_the_page(struct page *page, unsigned int order)
		__free_pages_ok(page, order, FPI_NONE);
		}

		/**
		* __free_pages - Free pages allocated with alloc_pages().
		* @page: The page pointer returned from alloc_pages().
		* @order: The order of the allocation.
		*
		* This function can free multi-page allocations that are not compound
		* pages. It does not check that the @order passed in matches that of
		* the allocation, so it is easy to leak memory. Freeing more memory
		* than was allocated will probably emit a warning.
		*
		* If the last reference to this page is speculative, it will be released
		* by put_page() which only frees the first page of a non-compound
		* allocation. To prevent the remaining pages from being leaked, we free
		* the subsequent pages here. If you want to use the page's reference
		* count to decide when to free the allocation, you should allocate a
		* compound page, and use put_page() instead of __free_pages().
		*
		* Context: May be called in interrupt context or while holding a normal
		* spinlock, but not in NMI context or while holding a raw spinlock.
		*/
		void __free_pages(struct page *page, unsigned int order)
		{
		if (put_page_testzero(page))