svn commit: r251297 - head/sys/dev/xen/netfront

[Adam McDougall]

On 06/03/13 09:00, Andre Oppermann wrote:
> Author: andre
> Date: Mon Jun  3 13:00:33 2013
> New Revision: 251297
> URL: http://svnweb.freebsd.org/changeset/base/251297
> 
> Log:
>   Specify a maximum TSO length limiting the segment chain to what the
>   Xen host side can handle after defragmentation.
>   
>   This prevents the driver from throwing away too long TSO chains and
>   improves the performance on Amazon AWS instances with 10GigE virtual
>   interfaces to the normally expected throughput.
>   
>   Submitted by:	cperciva (earlier version)
>   Reviewed by:	cperciva
>   Tested by:	cperciva
>   MFC after:	1 week
> 
> Modified:
>   head/sys/dev/xen/netfront/netfront.c
> 
> Modified: head/sys/dev/xen/netfront/netfront.c
> ==============================================================================
> --- head/sys/dev/xen/netfront/netfront.c	Mon Jun  3 12:55:13 2013	(r251296)
> +++ head/sys/dev/xen/netfront/netfront.c	Mon Jun  3 13:00:33 2013	(r251297)
> @@ -134,6 +134,7 @@ static const int MODPARM_rx_flip = 0;
>   * to mirror the Linux MAX_SKB_FRAGS constant.
>   */
>  #define	MAX_TX_REQ_FRAGS (65536 / PAGE_SIZE + 2)
> +#define	NF_TSO_MAXBURST ((IP_MAXPACKET / PAGE_SIZE) * MCLBYTES)
>  
>  #define RX_COPY_THRESHOLD 256
>  
> @@ -2122,6 +2123,7 @@ create_netdev(device_t dev)
>  	
>      	ifp->if_hwassist = XN_CSUM_FEATURES;
>      	ifp->if_capabilities = IFCAP_HWCSUM;
> +	ifp->if_hw_tsomax = NF_TSO_MAXBURST;
>  	
>      	ether_ifattach(ifp, np->mac);
>      	callout_init(&np->xn_stat_ch, CALLOUT_MPSAFE);

Can this and r251296 be MFC'ed yet or does it need more work to pass
muster?  Thinking ahead to my next deployment build.  Thanks.