From: Michael Dalton <mwdalton@google.com>
Date: Fri, 17 Jan 2014 06:23:25 +0000 (-0800)
Subject: net: allow > 0 order atomic page alloc in skb_page_frag_refill
X-Git-Tag: firefly_0821_release~176^2~4570^2~114^2~5
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=097b4f19e508015ca65a28ea4876740d35a19eea;p=firefly-linux-kernel-4.4.55.git

net: allow > 0 order atomic page alloc in skb_page_frag_refill

skb_page_frag_refill currently permits only order-0 page allocs
unless GFP_WAIT is used. Change skb_page_frag_refill to attempt
higher-order page allocations whether or not GFP_WAIT is used. If
memory cannot be allocated, the allocator will fall back to
successively smaller page allocs (down to order-0 page allocs).

This change brings skb_page_frag_refill in line with the existing
page allocation strategy employed by netdev_alloc_frag, which attempts
higher-order page allocations whether or not GFP_WAIT is set, falling
back to successively lower-order page allocations on failure. Part
of migration of virtio-net to per-receive queue page frag allocators.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Michael Dalton <mwdalton@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/sock.c b/net/core/sock.c
index 85ad6f0d3898..b3f7ee3008a0 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1836,9 +1836,7 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio)
 		put_page(pfrag->page);
 	}
 
-	/* We restrict high order allocations to users that can afford to wait */
-	order = (prio & __GFP_WAIT) ? SKB_FRAG_PAGE_ORDER : 0;
-
+	order = SKB_FRAG_PAGE_ORDER;
 	do {
 		gfp_t gfp = prio;