net: ena: Do not waste napi skb cache

By profiling, discovered that ena device driver allocates skb by
build_skb() and frees by napi_skb_cache_put(). Because the driver
does not use napi skb cache in allocation path, napi skb cache is
periodically filled and flushed. This is waste of napi skb cache.

As ena_alloc_skb() is called only in napi, Use napi_build_skb()
and napi_alloc_skb() when allocating skb.

This patch was tested on aws a1.metal instance.

[ jwiedmann.dev@gmail.com: Use napi_alloc_skb() instead of
  netdev_alloc_skb_ip_align() to keep things consistent. ]

Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Link: https://lore.kernel.org/r/YfUAkA9BhyOJRT4B@ip-172-31-19-208.ap-northeast-1.compute.internal
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 53080fd..07444ae 100644 (file)
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1400,10 +1400,9 @@ static struct sk_buff *ena_alloc_skb(struct ena_ring *rx_ring, void *first_frag)
        struct sk_buff *skb;
 
        if (!first_frag)
-               skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
-                                               rx_ring->rx_copybreak);
+               skb = napi_alloc_skb(rx_ring->napi, rx_ring->rx_copybreak);
        else
-               skb = build_skb(first_frag, ENA_PAGE_SIZE);
+               skb = napi_build_skb(first_frag, ENA_PAGE_SIZE);
 
        if (unlikely(!skb)) {
                ena_increase_stat(&rx_ring->rx_stats.skb_alloc_fail, 1,