* [PATCH] chelsio: add headroom in RX path @ 2013-03-20 16:33 Eric Dumazet 2013-03-20 17:29 ` David Miller 2013-03-20 18:30 ` [PATCH] chelsio: use netdev_alloc_skb Stephen Hemminger 0 siblings, 2 replies; 7+ messages in thread From: Eric Dumazet @ 2013-03-20 16:33 UTC (permalink / raw) To: David Miller; +Cc: netdev From: Eric Dumazet <edumazet@google.com> Drivers should reserve some headroom in skb used in receive path, to avoid future head reallocation. One possible way to do that is to use dev_alloc_skb() instead of alloc_skb(), so that NET_SKB_PAD bytes are reserved. Signed-off-by: Eric Dumazet <edumazet@google.com> --- drivers/net/ethernet/chelsio/cxgb/sge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.c b/drivers/net/ethernet/chelsio/cxgb/sge.c index 4829769..89bef50 100644 --- a/drivers/net/ethernet/chelsio/cxgb/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb/sge.c @@ -835,7 +835,7 @@ static void refill_free_list(struct sge *sge, struct freelQ *q) struct sk_buff *skb; dma_addr_t mapping; - skb = alloc_skb(q->rx_buffer_size, GFP_ATOMIC); + skb = dev_alloc_skb(q->rx_buffer_size); if (!skb) break; ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] chelsio: add headroom in RX path 2013-03-20 16:33 [PATCH] chelsio: add headroom in RX path Eric Dumazet @ 2013-03-20 17:29 ` David Miller 2013-03-20 18:30 ` [PATCH] chelsio: use netdev_alloc_skb Stephen Hemminger 1 sibling, 0 replies; 7+ messages in thread From: David Miller @ 2013-03-20 17:29 UTC (permalink / raw) To: eric.dumazet; +Cc: netdev From: Eric Dumazet <eric.dumazet@gmail.com> Date: Wed, 20 Mar 2013 09:33:19 -0700 > From: Eric Dumazet <edumazet@google.com> > > Drivers should reserve some headroom in skb used in receive path, > to avoid future head reallocation. > > One possible way to do that is to use dev_alloc_skb() instead > of alloc_skb(), so that NET_SKB_PAD bytes are reserved. > > Signed-off-by: Eric Dumazet <edumazet@google.com> Applied, thanks Eric. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] chelsio: use netdev_alloc_skb 2013-03-20 16:33 [PATCH] chelsio: add headroom in RX path Eric Dumazet 2013-03-20 17:29 ` David Miller @ 2013-03-20 18:30 ` Stephen Hemminger 2013-03-20 18:42 ` Eric Dumazet 2013-03-20 18:44 ` [PATCH] chelsio: use netdev_alloc_skb Eric Dumazet 1 sibling, 2 replies; 7+ messages in thread From: Stephen Hemminger @ 2013-03-20 18:30 UTC (permalink / raw) To: Eric Dumazet; +Cc: David Miller, netdev This extends on Eric's patch. It uses netdev_alloc_skb which fixes a couple of other issues. * driver was never setting skb->dev on the received buffer * copybreak allocation wasn't padding buffer * copybreak assumed that ip alignment padding was always 2 (it is platform dependent) Compile tested only, don't have this hardware. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> --- a/drivers/net/ethernet/chelsio/cxgb/sge.c 2013-03-20 11:13:47.950986878 -0700 +++ b/drivers/net/ethernet/chelsio/cxgb/sge.c 2013-03-20 11:24:26.942722757 -0700 @@ -835,7 +835,7 @@ static void refill_free_list(struct sge struct sk_buff *skb; dma_addr_t mapping; - skb = dev_alloc_skb(q->rx_buffer_size); + skb = netdev_alloc_skb(sge->netdev, q->rx_buffer_size); if (!skb) break; @@ -1039,18 +1039,18 @@ MODULE_PARM_DESC(copybreak, "Receive cop * threshold and the packet is too big to copy, or (b) the packet should * be copied but there is no memory for the copy. */ -static inline struct sk_buff *get_packet(struct pci_dev *pdev, +static inline struct sk_buff *get_packet(struct net_device *netdev, + struct pci_dev *pdev, struct freelQ *fl, unsigned int len) { struct sk_buff *skb; const struct freelQ_ce *ce = &fl->centries[fl->cidx]; if (len < copybreak) { - skb = alloc_skb(len + 2, GFP_ATOMIC); + skb = netdev_alloc_skb_ip_align(netdev, len + 2); if (!skb) goto use_orig_buf; - skb_reserve(skb, 2); /* align IP header */ skb_put(skb, len); pci_dma_sync_single_for_cpu(pdev, dma_unmap_addr(ce, dma_addr), @@ -1360,7 +1360,7 @@ static void sge_rx(struct sge *sge, stru struct sge_port_stats *st; struct net_device *dev; - skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad); + skb = get_packet(sge->netdev, adapter->pdev, fl, len - sge->rx_pkt_pad); if (unlikely(!skb)) { sge->stats.rx_drops++; return; ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] chelsio: use netdev_alloc_skb 2013-03-20 18:30 ` [PATCH] chelsio: use netdev_alloc_skb Stephen Hemminger @ 2013-03-20 18:42 ` Eric Dumazet 2013-03-20 19:02 ` [PATCH v2] chelsio: use netdev_alloc_skb_ip_align Stephen Hemminger 2013-03-20 18:44 ` [PATCH] chelsio: use netdev_alloc_skb Eric Dumazet 1 sibling, 1 reply; 7+ messages in thread From: Eric Dumazet @ 2013-03-20 18:42 UTC (permalink / raw) To: Stephen Hemminger; +Cc: David Miller, netdev On Wed, 2013-03-20 at 11:30 -0700, Stephen Hemminger wrote: > This extends on Eric's patch. It uses netdev_alloc_skb which fixes a couple of > other issues. > * driver was never setting skb->dev on the received buffer > * copybreak allocation wasn't padding buffer > * copybreak assumed that ip alignment padding was always 2 (it is platform dependent) > > Compile tested only, don't have this hardware. > > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> > > > --- a/drivers/net/ethernet/chelsio/cxgb/sge.c 2013-03-20 11:13:47.950986878 -0700 > +++ b/drivers/net/ethernet/chelsio/cxgb/sge.c 2013-03-20 11:24:26.942722757 -0700 > @@ -835,7 +835,7 @@ static void refill_free_list(struct sge > struct sk_buff *skb; > dma_addr_t mapping; > > - skb = dev_alloc_skb(q->rx_buffer_size); > + skb = netdev_alloc_skb(sge->netdev, q->rx_buffer_size); > if (!skb) > break; Well, this (skb->dev = dev) is done in eth_type_trans() Many drivers use dev_alloc_skb(), I am not sure we really want to change them. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2] chelsio: use netdev_alloc_skb_ip_align 2013-03-20 18:42 ` Eric Dumazet @ 2013-03-20 19:02 ` Stephen Hemminger 2013-03-20 19:25 ` David Miller 0 siblings, 1 reply; 7+ messages in thread From: Stephen Hemminger @ 2013-03-20 19:02 UTC (permalink / raw) To: Eric Dumazet; +Cc: David Miller, netdev Use netdev_alloc_sk_ip_align in the case where packet is copied. This handles case where NET_IP_ALIGN == 0 as well as adding required header padding. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> --- a/drivers/net/ethernet/chelsio/cxgb/sge.c 2013-03-20 11:13:47.950986878 -0700 +++ b/drivers/net/ethernet/chelsio/cxgb/sge.c 2013-03-20 12:00:01.551115729 -0700 @@ -1046,11 +1046,10 @@ static inline struct sk_buff *get_packet const struct freelQ_ce *ce = &fl->centries[fl->cidx]; if (len < copybreak) { - skb = alloc_skb(len + 2, GFP_ATOMIC); + skb = netdev_alloc_skb_ip_align(NULL, len); if (!skb) goto use_orig_buf; - skb_reserve(skb, 2); /* align IP header */ skb_put(skb, len); pci_dma_sync_single_for_cpu(pdev, dma_unmap_addr(ce, dma_addr), ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] chelsio: use netdev_alloc_skb_ip_align 2013-03-20 19:02 ` [PATCH v2] chelsio: use netdev_alloc_skb_ip_align Stephen Hemminger @ 2013-03-20 19:25 ` David Miller 0 siblings, 0 replies; 7+ messages in thread From: David Miller @ 2013-03-20 19:25 UTC (permalink / raw) To: stephen; +Cc: eric.dumazet, netdev From: Stephen Hemminger <stephen@networkplumber.org> Date: Wed, 20 Mar 2013 12:02:41 -0700 > Use netdev_alloc_sk_ip_align in the case where packet is copied. > This handles case where NET_IP_ALIGN == 0 as well as adding required header > padding. > > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Applied, thanks Stephen. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] chelsio: use netdev_alloc_skb 2013-03-20 18:30 ` [PATCH] chelsio: use netdev_alloc_skb Stephen Hemminger 2013-03-20 18:42 ` Eric Dumazet @ 2013-03-20 18:44 ` Eric Dumazet 1 sibling, 0 replies; 7+ messages in thread From: Eric Dumazet @ 2013-03-20 18:44 UTC (permalink / raw) To: Stephen Hemminger; +Cc: David Miller, netdev On Wed, 2013-03-20 at 11:30 -0700, Stephen Hemminger wrote: > - skb = alloc_skb(len + 2, GFP_ATOMIC); > + skb = netdev_alloc_skb_ip_align(netdev, len + 2); > if (!skb) > goto use_orig_buf; > If you use the helper, no need for 'len + 2' but : netdev_alloc_skb_ip_align(netdev, len); ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-03-20 19:25 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-03-20 16:33 [PATCH] chelsio: add headroom in RX path Eric Dumazet 2013-03-20 17:29 ` David Miller 2013-03-20 18:30 ` [PATCH] chelsio: use netdev_alloc_skb Stephen Hemminger 2013-03-20 18:42 ` Eric Dumazet 2013-03-20 19:02 ` [PATCH v2] chelsio: use netdev_alloc_skb_ip_align Stephen Hemminger 2013-03-20 19:25 ` David Miller 2013-03-20 18:44 ` [PATCH] chelsio: use netdev_alloc_skb Eric Dumazet
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