Commit bc38f30f authored Feb 02, 2021 by Alexander Lobakin Committed by Jakub Kicinski Feb 04, 2021

net: introduce common dev_page_is_reusable()



A bunch of drivers test the page before reusing/recycling for two
common conditions:
 - if a page was allocated under memory pressure (pfmemalloc page);
 - if a page was allocated at a distant memory node (to exclude
   slowdowns).

Introduce a new common inline for doing this, with likely() already
folded inside to make driver code a bit simpler.

Suggested-by: David Rientjes <rientjes@google.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 48f971c9

include/linux/skbuff.h

+16 −0

Original line number	Diff line number	Diff line
		@@ -2938,6 +2938,22 @@ static inline struct page *dev_alloc_page(void)
		return dev_alloc_pages(0);
		}

		/**
		* dev_page_is_reusable - check whether a page can be reused for network Rx
		* @page: the page to test
		*
		* A page shouldn't be considered for reusing/recycling if it was allocated
		* under memory pressure or at a distant memory node.
		*
		* Returns false if this page should be returned to page allocator, true
		* otherwise.
		*/
		static inline bool dev_page_is_reusable(const struct page *page)
		{
		return likely(page_to_nid(page) == numa_mem_id() &&
		!page_is_pfmemalloc(page));
		}

		/**
		* skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
		* @page: The page that was allocated from skb_alloc_page