lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 22 Sep 2013 22:58:27 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Anirban Chakraborty <abchak@...iper.net>
Cc:	Wei Liu <wei.liu2@...rix.com>,
	"<netdev@...r.kernel.org>" <netdev@...r.kernel.org>,
	"<xen-devel@...ts.xen.org>" <xen-devel@...ts.xen.org>,
	Ian Campbell <ian.campbell@...rix.com>
Subject: Re: [PATCH net-next] xen-netfront: convert to GRO API and advertise
 this feature

On Sun, 2013-09-22 at 23:09 +0000, Anirban Chakraborty wrote:
> On Sep 22, 2013, at 7:55 AM, Eric Dumazet <eric.dumazet@...il.com> wrote:
> 
> > On Sat, 2013-09-21 at 17:05 +0100, Wei Liu wrote:
> >> Anirban was seeing netfront received MTU size packets, which downgraded
> >> throughput. The following patch makes netfront use GRO API which
> >> improves throughput for that case.
> > 
> >> -	netdev->hw_features	= NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
> >> +	netdev->hw_features	= NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO |
> >> +				  NETIF_F_GRO;
> > 
> > 
> > This part is not needed.
> 
> Shouldn't the flag be set? In dev_gro_receive() we do check if this flag is set or not:
> 
>         if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
>                goto normal;

Drivers do not set NETIF_F_GRO themselves, they do not need to.

Look at other drivers which are GRO ready : NETIF_F_GRO is enabled by
default by core networking stack, in register_netdevice()


dev->hw_features |= NETIF_F_SOFT_FEATURES;
dev->features |= NETIF_F_SOFT_FEATURES;



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists