RE: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-06 Thread David Laight
From: Eric Dumazet [mailto:eric.duma...@gmail.com] > Sent: 03 July 2015 17:39 > On Fri, 2015-07-03 at 16:18 +, David Laight wrote: > > > Even on x86 aligning the ethernet receive data on a 4n+2 > > boundary is likely to give marginally better performance > > than aligning on a 4n boundary. >

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-03 Thread Eric Dumazet
On Fri, 2015-07-03 at 16:18 +, David Laight wrote: > Even on x86 aligning the ethernet receive data on a 4n+2 > boundary is likely to give marginally better performance > than aligning on a 4n boundary. You are coming late to the party. Intel guys decided to change NET_IP_ALIGN to 0 (it was

RE: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-03 Thread David Laight
From: Eric Dumazet > Sent: 01 July 2015 23:14 > To: Joe Perches ... > > > Then please use netdev_alloc_skb_ip_align(), so that you get rid of > > > skb_reserve() > > > > It seems there are ~50 of these in the kernel tree > > that could be converted. > > > > Make sure the 2 is really NET_IP_ALIGN >

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Joe Perches
On Thu, 2015-07-02 at 00:13 +0200, Eric Dumazet wrote: > On Wed, 2015-07-01 at 10:06 -0700, Joe Perches wrote: > > On Wed, 2015-07-01 at 12:56 +0200, Eric Dumazet wrote: > > > On Tue, 2015-06-30 at 20:25 +0300, Nicolae Rosia wrote: > > > > diff --git a/drivers/net/ethernet/cadence/macb.c > > > > b

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Eric Dumazet
On Wed, 2015-07-01 at 10:06 -0700, Joe Perches wrote: > On Wed, 2015-07-01 at 12:56 +0200, Eric Dumazet wrote: > > On Tue, 2015-06-30 at 20:25 +0300, Nicolae Rosia wrote: > > > diff --git a/drivers/net/ethernet/cadence/macb.c > > > b/drivers/net/ethernet/cadence/macb.c > [] > > > @@ -2554,9 +2554,

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Joe Perches
On Wed, 2015-07-01 at 12:56 +0200, Eric Dumazet wrote: > On Tue, 2015-06-30 at 20:25 +0300, Nicolae Rosia wrote: > > diff --git a/drivers/net/ethernet/cadence/macb.c > > b/drivers/net/ethernet/cadence/macb.c [] > > @@ -2554,9 +2554,9 @@ static void at91ether_rx(struct net_device *dev) > > whil

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Eric Dumazet
On Wed, 2015-07-01 at 18:53 +0300, Nicolae Rosia wrote: > On Wed, Jul 1, 2015 at 6:33 PM, Eric Dumazet wrote: > [...] > > This only matters in terms of few nano seconds per packet, so for 10Gb+ > > NIC anyway. Absolute noise for most NIC. > > > I'll give it a try and benchmark. > I achieved a huge

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Nicolae Rosia
On Wed, Jul 1, 2015 at 6:33 PM, Eric Dumazet wrote: [...] > This only matters in terms of few nano seconds per packet, so for 10Gb+ > NIC anyway. Absolute noise for most NIC. > I'll give it a try and benchmark. I achieved a huge speedup by moving TX into napi [0], but my hardware doesn't support m

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Eric Dumazet
On Wed, 2015-07-01 at 17:29 +0300, Nicolae Rosia wrote: > On 07/01/2015 04:44 PM, Eric Dumazet wrote: > > I really doubt this adapter can process millions of packets per second ? > I was suggesting this since I was taking into consideration the comment > from skbuff.c, "we can save several CPU cyc

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Nicolae Rosia
On 07/01/2015 04:44 PM, Eric Dumazet wrote: I really doubt this adapter can process millions of packets per second ? I was suggesting this since I was taking into consideration the comment from skbuff.c, "we can save several CPU cycles by avoiding having to disable and re-enable IRQs." Is ther

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Eric Dumazet
On Wed, 2015-07-01 at 16:29 +0300, Nicolae Rosia wrote: > On 07/01/2015 01:56 PM, Eric Dumazet wrote: > > Then please use netdev_alloc_skb_ip_align(), so that you get rid of > > skb_reserve() > Thank you for the suggestion. > I can do that. > A related question, should I also replace netdev_alloc w

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Nicolae Rosia
On 07/01/2015 01:56 PM, Eric Dumazet wrote: Then please use netdev_alloc_skb_ip_align(), so that you get rid of skb_reserve() Thank you for the suggestion. I can do that. A related question, should I also replace netdev_alloc with napi_alloc_skb in places where I have a napi struct? -- To unsu

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Eric Dumazet
On Tue, 2015-06-30 at 20:25 +0300, Nicolae Rosia wrote: > Signed-off-by: Nicolae Rosia > --- > drivers/net/ethernet/cadence/macb.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/cadence/macb.c > b/drivers/net/ethernet/cadence/macb.c > index cae

Re: [PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-07-01 Thread Nicolas Ferre
Le 30/06/2015 19:25, Nicolae Rosia a écrit : > > Signed-off-by: Nicolae Rosia Acked-by: Nicolas Ferre Thanks, bye. > --- > drivers/net/ethernet/cadence/macb.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/cadence/macb.c > b/drivers/net/et

[PATCH net-next] net: macb: replace literal constant with NET_IP_ALIGN

2015-06-30 Thread Nicolae Rosia
Signed-off-by: Nicolae Rosia --- drivers/net/ethernet/cadence/macb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index caeb395..dbb5160 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/dr