Merge branch 'skb_alloc_pages'

Alexander Duyck says:

====================
Replace __skb_alloc_pages with simpler function

This patch series replaces __skb_alloc_pages with a much simpler function,
__dev_alloc_pages.  The main difference between the two is that
__skb_alloc_pages had an sk_buff pointer that was being passed as NULL in
call places where it was called.  In a couple of cases the NULL was passed
by variable and this led to unnecessary code being run.

As such in order to simplify things the __dev_alloc_pages call only takes a
mask and the page order being requested.  In addition it takes advantage of
several behaviors already built into the page allocator so that it can just
set GFP flags unconditionally.

v2: Renamed functions to dev_alloc_page(s) instead of netdev_alloc_page(s)
    Removed __GFP_COLD flag from usb code as it was redundant
v3: Update patch descriptions and subjects to match changes in v2
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 28 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 103fbe8113f8..73c370e615de 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2185,46 +2185,51 @@ static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
 }
 
 /**
- *	__skb_alloc_pages - allocate pages for ps-rx on a skb and preserve pfmemalloc data
- *	@gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
- *	@skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
- *	@order: size of the allocation
+ * __dev_alloc_pages - allocate page for network Rx
+ * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
+ * @order: size of the allocation
  *
- * 	Allocate a new page.
+ * Allocate a new page.
  *
- * 	%NULL is returned if there is no free memory.
+ * %NULL is returned if there is no free memory.
 */
-static inline struct page *__skb_alloc_pages(gfp_t gfp_mask,
-					      struct sk_buff *skb,
-					      unsigned int order)
-{
-	struct page *page;
-
-	gfp_mask |= __GFP_COLD;
-
-	if (!(gfp_mask & __GFP_NOMEMALLOC))
-		gfp_mask |= __GFP_MEMALLOC;
+static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
+					     unsigned int order)
+{
+	/* This piece of code contains several assumptions.
+	 * 1.  This is for device Rx, therefor a cold page is preferred.
+	 * 2.  The expectation is the user wants a compound page.
+	 * 3.  If requesting a order 0 page it will not be compound
+	 *     due to the check to see if order has a value in prep_new_page
+	 * 4.  __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
+	 *     code in gfp_to_alloc_flags that should be enforcing this.
+	 */
+	gfp_mask |= __GFP_COLD | __GFP_COMP | __GFP_MEMALLOC;
 
-	page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
-	if (skb && page && page->pfmemalloc)
-		skb->pfmemalloc = true;
+	return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
+}
 
-	return page;
+static inline struct page *dev_alloc_pages(unsigned int order)
+{
+	return __dev_alloc_pages(GFP_ATOMIC, order);
 }
 
 /**
- *	__skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
- *	@gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
- *	@skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
+ * __dev_alloc_page - allocate a page for network Rx
+ * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
  *
- * 	Allocate a new page.
+ * Allocate a new page.
  *
- * 	%NULL is returned if there is no free memory.
+ * %NULL is returned if there is no free memory.
  */
-static inline struct page *__skb_alloc_page(gfp_t gfp_mask,
-					     struct sk_buff *skb)
+static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
+{
+	return __dev_alloc_pages(gfp_mask, 0);
+}
+
+static inline struct page *dev_alloc_page(void)
 {
-	return __skb_alloc_pages(gfp_mask, skb, 0);
+	return __dev_alloc_page(GFP_ATOMIC);
 }
 
 /**