Re: [PATCH net-next v2 1/4] net: allow > 0 order atomic page alloc in skb_page_frag_refill
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2014-01-08 18:08:41
On Mon, Jan 06, 2014 at 09:25:52PM -0800, Michael Dalton wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- net/core/sock.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)diff --git a/net/core/sock.c b/net/core/sock.c index 5393b4b..a0d522a 100644 --- a/net/core/sock.c +++ b/net/core/sock.c@@ -1865,9 +1865,7 @@ 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;
Eric said we also need a patch to add __GFP_NORETRY, right? Probably before this one in series.
-- 1.8.5.1