From: Eric Dumazet <eric.dumazet@gmail.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
Cc: "Alexander Duyck" <alexander.h.duyck@intel.com>,
"David Miller" <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
"Neal Cardwell" <ncardwell@google.com>,
"Tom Herbert" <therbert@google.com>,
"Jeff Kirsher" <jeffrey.t.kirsher@intel.com>,
"Michael Chan" <mchan@broadcom.com>,
"Matt Carlson" <mcarlson@broadcom.com>,
"Herbert Xu" <herbert@gondor.apana.org.au>,
"Ben Hutchings" <bhutchings@solarflare.com>,
"Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>,
"Maciej Żenczykowski" <maze@google.com>
Subject: Re: [PATCH 3/4 v2 net-next] net: make GRO aware of skb->head_frag
Date: Tue, 01 May 2012 08:39:38 +0200 [thread overview]
Message-ID: <1335854378.11396.26.camel@edumazet-glaptop> (raw)
In-Reply-To: <CAKgT0UdeVvJe6k5OitkKgujSw3SQSOvtQ84KrPch8xdd=5ub1A@mail.gmail.com>
On Mon, 2012-04-30 at 22:33 -0700, Alexander Duyck wrote:
> The question I had was more specific to GRO. As long as we have
> skb->users == 1 and the skb isn't cloned we should be fine. It just
> hadn't occurred to me before that napi_gro_receive had the extra
> requirement that the skb couldn't be cloned.
>
OK
By the way, even if skb was cloned, we would be allowed to steal
skb->head.
When we clone an oskb we :
1) allocate a struct nskb sk_buff (or use the shadow in case of TCP)
2) increment dataref
3) link skb->head
After cloning() nskb->users == 1, and oskb->users is unchanged
I believe you are referring to skb_get(oskb), that ones increment
oskb->users and skb_shared(oskb) then returns true.
next prev parent reply other threads:[~2012-05-01 6:39 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-27 10:37 [PATCH 3/4 net-next] net: make GRO aware of skb->head_frag Eric Dumazet
2012-04-30 17:54 ` Eric Dumazet
2012-04-30 18:10 ` [PATCH 3/4 v2 " Eric Dumazet
2012-04-30 23:36 ` Alexander Duyck
2012-05-01 1:27 ` Eric Dumazet
2012-05-01 5:33 ` Alexander Duyck
2012-05-01 6:39 ` Eric Dumazet [this message]
2012-05-01 16:17 ` Alexander Duyck
2012-05-01 17:04 ` Eric Dumazet
2012-05-01 19:45 ` Alexander Duyck
2012-05-02 2:45 ` Eric Dumazet
2012-05-02 8:24 ` Eric Dumazet
2012-05-02 16:16 ` Alexander Duyck
2012-05-02 16:19 ` Eric Dumazet
2012-05-02 16:27 ` Eric Dumazet
2012-05-02 17:04 ` Alexander Duyck
2012-05-02 17:02 ` Alexander Duyck
2012-05-02 17:16 ` Rick Jones
2012-05-01 22:58 ` Alexander Duyck
2012-05-01 23:10 ` Alexander Duyck
2012-05-02 2:47 ` Eric Dumazet
2012-05-02 3:54 ` Eric Dumazet
2012-05-02 8:13 ` [PATCH net-next] net: take care of cloned skbs in tcp_try_coalesce() Eric Dumazet
2012-05-02 15:52 ` Alexander Duyck
2012-05-02 16:12 ` Eric Dumazet
2012-05-02 16:27 ` Alexander Duyck
2012-05-02 16:46 ` Eric Dumazet
2012-05-02 17:55 ` [PATCH v2 " Eric Dumazet
2012-05-02 19:58 ` [PATCH net-next] net: implement tcp coalescing in tcp_queue_rcv() Eric Dumazet
2012-05-02 20:11 ` Joe Perches
2012-05-02 20:23 ` Eric Dumazet
2012-05-02 20:34 ` Joe Perches
2012-05-03 0:32 ` David Miller
2012-05-03 1:11 ` David Miller
2012-05-03 2:14 ` Eric Dumazet
2012-05-03 2:21 ` David Miller
2012-05-03 1:11 ` [PATCH v2 net-next] net: take care of cloned skbs in tcp_try_coalesce() David Miller
2012-05-02 18:05 ` [PATCH " Alexander Duyck
2012-05-02 18:15 ` Eric Dumazet
2012-05-02 20:55 ` Alexander Duyck
2012-05-03 1:52 ` Eric Dumazet
2012-05-03 3:00 ` Alexander Duyck
2012-05-03 3:14 ` Eric Dumazet
2012-05-03 3:28 ` Alexander Duyck
2012-05-01 1:48 ` [PATCH 3/4 v2 net-next] net: make GRO aware of skb->head_frag David Miller
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