From: Ben Greear <greearb@candelatech•com>
To: Neil Horman <nhorman@tuxdriver•com>
Cc: Eric Dumazet <eric.dumazet@gmail•com>,
Jiri Pirko <jpirko@redhat•com>,
netdev@vger•kernel.org, Alexey Dobriyan <adobriyan@gmail•com>,
"David S. Miller" <davem@davemloft•net>,
robert.olsson@its•uu.se
Subject: Re: [PATCH] pktgen: Clone skb to avoid corruption of skbs in ndo_start_xmit methods
Date: Wed, 20 Jul 2011 09:33:20 -0700 [thread overview]
Message-ID: <4E270350.7050904@candelatech.com> (raw)
In-Reply-To: <20110720151827.GD12349@hmsreliant.think-freely.org>
On 07/20/2011 08:18 AM, Neil Horman wrote:
> On Wed, Jul 20, 2011 at 06:24:15AM +0200, Eric Dumazet wrote:
>> Le mardi 19 juillet 2011 à 22:07 -0400, Neil Horman a écrit :
>>>>
>>> I think this is a good idea. It lets pktgen dynamically make the clone/share
>>> decision dynamically and only impacts performance for those systems.
>>>
>>
>> Just let pktgen refuse to use clone_skb command for these devices.
>>
> copy that, This is by no means final, but what do you think of this? If its
> agreeable to you, Ben, et al. I can add this to my local tree and start auditing
> all the drivers that may need to have the flag set.
>
> Regards
> Neil
>
>
> diff --git a/include/linux/if.h b/include/linux/if.h
> index 3bc63e6..ae904fe 100644
> --- a/include/linux/if.h
> +++ b/include/linux/if.h
> @@ -76,6 +76,7 @@
> #define IFF_BRIDGE_PORT 0x4000 /* device used as bridge port */
> #define IFF_OVS_DATAPATH 0x8000 /* device used as Open vSwitch
> * datapath port */
> +#define IFF_CANT_SHARE_SKB 0x10000 /* Device can't share skbs in tx path */
>
> #define IF_GET_IFACE 0x0001 /* for querying only */
> #define IF_GET_PROTO 0x0002
> diff --git a/net/core/pktgen.c b/net/core/pktgen.c
> index f76079c..bf6d88d 100644
> --- a/net/core/pktgen.c
> +++ b/net/core/pktgen.c
> @@ -1071,6 +1071,9 @@ static ssize_t pktgen_if_write(struct file *file,
> if (len< 0)
> return len;
>
> + if (pkt_dev->priv_flags& IFF_CANT_SHARE_SKB)
> + return -EOPNOTSUPP;
> +
> i += len;
> pkt_dev->clone_skb = value;
>
Please only return an error if value > 1.
Also, if there is any place where user can configure pkt_dev,
you would want code there to check for the CANT_SHARE_SKB flag
and force clone_skb to zero if user changes to a different
device that cannot share skbs.
Thanks,
Ben
--
Ben Greear <greearb@candelatech•com>
Candela Technologies Inc http://www.candelatech.com
next prev parent reply other threads:[~2011-07-20 16:33 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-19 19:52 [PATCH] pktgen: Clone skb to avoid corruption of skbs in ndo_start_xmit methods Neil Horman
2011-07-19 20:02 ` Eric Dumazet
2011-07-19 20:17 ` Joe Perches
2011-07-19 20:29 ` Jiri Pirko
2011-07-19 20:41 ` Eric Dumazet
2011-07-19 21:01 ` Ben Greear
2011-07-20 0:19 ` Neil Horman
2011-07-20 0:25 ` Rick Jones
2011-07-20 15:23 ` Loke, Chetan
2011-07-20 0:43 ` Eric Dumazet
2011-07-20 0:52 ` Ben Greear
2011-07-20 2:07 ` Neil Horman
2011-07-20 4:19 ` Ben Greear
2011-07-20 4:24 ` Eric Dumazet
2011-07-20 15:17 ` Loke, Chetan
2011-07-20 15:18 ` Neil Horman
2011-07-20 15:30 ` Eric Dumazet
2011-07-20 15:39 ` Neil Horman
2011-07-20 15:44 ` Eric Dumazet
2011-07-20 16:19 ` Neil Horman
2011-07-20 15:35 ` Michał Mirosław
2011-07-20 15:40 ` Neil Horman
2011-07-20 16:08 ` Michał Mirosław
2011-07-20 16:18 ` Neil Horman
2011-07-20 16:37 ` Ben Greear
2011-07-20 16:33 ` Ben Greear [this message]
2011-07-20 16:36 ` Neil Horman
2011-07-21 22:01 ` David Miller
2011-07-21 22:14 ` Ben Greear
2011-07-21 22:19 ` David Miller
2011-07-21 22:26 ` Ben Greear
2011-07-21 23:50 ` Neil Horman
2011-07-22 0:08 ` David Miller
2011-07-22 1:37 ` Neil Horman
2011-07-20 1:59 ` Neil Horman
2011-07-25 19:45 ` [PATCH 0/2] pktgen: Clone skb to avoid corruption of skbs in ndo_start_xmit methods (v2) Neil Horman
2011-07-25 19:45 ` [PATCH 1/2] net: add IFF_SKB_TX_SHARED flag to priv_flags Neil Horman
2011-07-25 20:11 ` Eric Dumazet
2011-07-26 14:54 ` Neil Horman
2011-07-25 19:45 ` [PATCH 2/2] net: Audit drivers to identify those needing IFF_TX_SKB_SHARING cleared Neil Horman
2011-07-26 18:34 ` Krzysztof Halasa
2011-07-26 16:05 ` [PATCH 0/2] pktgen: Clone skb to avoid corruption of skbs in ndo_start_xmit methods (v3) Neil Horman
2011-07-26 16:05 ` [PATCH 1/2] net: add IFF_SKB_TX_SHARED flag to priv_flags Neil Horman
2011-07-28 5:42 ` David Miller
2011-07-28 8:15 ` Robert Olsson
2011-07-28 10:50 ` Neil Horman
2011-07-26 16:05 ` [PATCH 2/2] net: Audit drivers to identify those needing IFF_TX_SKB_SHARING cleared Neil Horman
2011-07-28 5:42 ` David Miller
2011-07-29 6:16 ` [PATCH 0/2] pktgen: Clone skb to avoid corruption of skbs in ndo_start_xmit methods (v3) Michael S. Tsirkin
2011-07-29 11:19 ` Neil Horman
2011-08-17 15:07 ` Ben Hutchings
2011-08-22 0:27 ` Neil Horman
2011-08-22 16:17 ` Ben Hutchings
2011-08-22 17:33 ` Ben Hutchings
2011-08-22 18:14 ` Neil Horman
2011-08-23 14:01 ` Ben Hutchings
2011-08-23 15:13 ` Neil Horman
2011-08-23 15:53 ` Ben Hutchings
2011-08-23 16:21 ` Neil Horman
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