From: Eric Dumazet <dada1@cosmosbay•com>
To: Jarek Poplawski <jarkao2@gmail•com>
Cc: "David S. Miller" <davem@davemloft•net>,
Linux Netdev List <netdev@vger•kernel.org>,
Patrick McHardy <kaber@trash•net>
Subject: Re: [PATCH] net: release dst entry in dev_hard_start_xmit()
Date: Tue, 12 May 2009 22:52:27 +0200 [thread overview]
Message-ID: <4A09E18B.3020402@cosmosbay.com> (raw)
In-Reply-To: <20090512200515.GB2757@ami.dom.local>
Jarek Poplawski a écrit :
> On Tue, May 12, 2009 at 09:44:52PM +0200, Eric Dumazet wrote:
>> Jarek Poplawski a écrit :
>>> On Tue, May 12, 2009 at 10:21:12AM +0200, Eric Dumazet wrote:
>>>> Eric Dumazet a écrit :
>>> ...
>>>>> List of devices that must clear this flag is :
>>>>>
>>>>> - loopback device, because it calls netif_rx() and quoting Patrick :
>>>>> "ip_route_input() doesn't accept loopback addresses, so loopback packets
>>>>> already need to have a dst_entry attached."
>>>>> - appletalk/ipddp.c : needs skb->dst in its xmit function
>>>>>
>>>>> - And all devices that call again dev_queue_xmit() from their xmit function
>>>>> (as some classifiers need skb->dst) : bonding, macvlan, eql, ifb, hdlc_fr
>>> Why not vlan (and/or maybe others in net/ using dev_queue_xmit)?
>>>
>> Yes I spoted vlan earlier this afternoon.
>>
>> For other net/*, I didnt not find candidates yet.
>
> Hmm..., if vlan, then why not pppoe (and/or maybe others in drivers/net/
> using dev_queue_xmit)?
>
As I said, I didnt found other relevant uses, but I am probably wrong :)
About ppoe for example, two calls to dev_queue_xmit() are not relevant.
One is from
static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
This is a normal direct call, not a call from its ndo_start_xmit()
Second one is from
static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
Same observation, there is no impact for this one as well.
So we have to care on device drivers that have a ndo_start_xmit() call that could
re-enter dev_queue_xmit(). Not care about drivers that call dev_queue_xmit() from
other paths.
next prev parent reply other threads:[~2009-05-12 20:52 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-20 11:40 [RFC] net: release dst entry in dev_queue_xmit() Eric Dumazet
2009-03-20 14:10 ` Neil Horman
2009-03-25 6:43 ` David Miller
2009-03-25 7:13 ` Eric Dumazet
2009-03-25 7:17 ` David Miller
2009-03-25 18:22 ` Jarek Poplawski
2009-03-25 18:41 ` Eric Dumazet
2009-03-25 19:18 ` Jarek Poplawski
2009-03-25 19:40 ` Eric Dumazet
2009-03-25 19:54 ` Jarek Poplawski
2009-03-25 20:28 ` Eric Dumazet
2009-03-25 21:12 ` Jarek Poplawski
2009-03-25 21:20 ` Patrick McHardy
2009-05-12 8:12 ` [PATCH] net: release dst entry in dev_hard_start_xmit() Eric Dumazet
2009-05-12 8:21 ` Eric Dumazet
2009-05-12 19:26 ` [PATCH, v2] " Eric Dumazet
2009-05-19 5:19 ` David Miller
2009-05-19 5:44 ` Eric Dumazet
2009-05-19 19:44 ` Eric Dumazet
2009-05-19 21:09 ` Jarek Poplawski
2009-05-19 21:21 ` Eric Dumazet
2009-05-19 21:24 ` David Miller
2009-05-12 19:27 ` [PATCH] " Jarek Poplawski
2009-05-12 19:44 ` Eric Dumazet
2009-05-12 20:05 ` Jarek Poplawski
2009-05-12 20:24 ` Jarek Poplawski
2009-05-12 20:52 ` Eric Dumazet [this message]
2009-05-12 20:59 ` Jarek Poplawski
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