diff options
| author | Giuseppe CAVALLARO <peppe.cavallaro@st.com> | 2011-10-18 01:39:55 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-19 19:24:18 -0400 |
| commit | 45db81e1590c82ddc735ccd33f8adab02528b3e3 (patch) | |
| tree | c3438feab991a27b0d1a696c8118d5d28f414e03 | |
| parent | 286a837217204b1ef105e3a554d0757e4fdfaac1 (diff) | |
stmmac: limit max_mtu in case of 4KiB and use __netdev_alloc_skb (V2)
Problem using big mtu around 4096 bytes is you end allocating (4096
+NET_SKB_PAD + NET_IP_ALIGN + sizeof(struct skb_shared_info) bytes ->
8192 bytes : order-1 pages
It's better to limit the mtu to SKB_MAX_HEAD(NET_SKB_PAD),
to have no more than one page per skb.
Also the patch changes the netdev_alloc_skb_ip_align() done in
init_dma_desc_rings() and uses a variant allowing GFP_KERNEL allocations
allowing the driver to load even in case of memory pressure.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 5eccd996cde..aeaa15b451d 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -474,11 +474,13 @@ static void init_dma_desc_rings(struct net_device *dev) for (i = 0; i < rxsize; i++) { struct dma_desc *p = priv->dma_rx + i; - skb = netdev_alloc_skb_ip_align(dev, bfsize); + skb = __netdev_alloc_skb(dev, bfsize + NET_IP_ALIGN, + GFP_KERNEL); if (unlikely(skb == NULL)) { pr_err("%s: Rx init fails; skb is NULL\n", __func__); break; } + skb_reserve(skb, NET_IP_ALIGN); priv->rx_skbuff[i] = skb; priv->rx_skbuff_dma[i] = dma_map_single(priv->device, skb->data, bfsize, DMA_FROM_DEVICE); @@ -1401,7 +1403,7 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu) if (priv->plat->enh_desc) max_mtu = JUMBO_LEN; else - max_mtu = BUF_SIZE_4KiB; + max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN); if ((new_mtu < 46) || (new_mtu > max_mtu)) { pr_err("%s: invalid MTU, max MTU is: %d\n", dev->name, max_mtu); |