From: David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
To: johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org
Cc: tomasw-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
linville-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [RFC v2] mac80211: assign needed_headroom/tailroom for netdevs
Date: Mon, 05 May 2008 16:14:58 -0700 (PDT) [thread overview]
Message-ID: <20080505.161458.46071527.davem@davemloft.net> (raw)
In-Reply-To: <1210027447.8012.15.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
Date: Tue, 06 May 2008 00:44:07 +0200
> Right, that makes sense. But will it ever return false? skb_cloned()
> returns true often enough, and we only accept linear skbs, but I think I
> don't understand yet what skb_header_cloned() vs. skb_cloned() refers
> to. Which exactly is the header space I'm allowed to modify when
> skb_header_cloned() returns false?
skb_header_cloned() will return false always if the buffer is not
cloned.
If it is cloned, it makes sure the data reference count allows
for modification of the buffer.
For normal traffic, you should see skb_header_cloned() always return
false unless a network tap like tcpdump is registered.
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next prev parent reply other threads:[~2008-05-05 23:14 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-04 21:24 [RFC] mac80211: assign needed_headroom/tailroom for netdevs Johannes Berg
[not found] ` <1209936253.7304.10.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-04 21:31 ` Johannes Berg
2008-05-04 21:32 ` [RFC v2] " Johannes Berg
[not found] ` <1209936745.7304.16.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 0:30 ` David Miller
[not found] ` <20080504.173051.133197507.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-05 7:22 ` Johannes Berg
[not found] ` <1209972139.3655.9.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 14:27 ` Tomas Winkler
[not found] ` <1ba2fa240805050727r2060b0b4x3a9b3240647b66b1-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-05-05 15:22 ` Johannes Berg
[not found] ` <1210000923.8245.26.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 17:15 ` Tomas Winkler
2008-05-05 17:57 ` Johannes Berg
2008-05-05 18:58 ` David Miller
[not found] ` <20080505.115855.137964071.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-05 19:05 ` Johannes Berg
2008-05-05 19:50 ` David Miller
2008-05-05 19:57 ` Johannes Berg
2008-05-05 20:02 ` David Miller
2008-05-05 20:10 ` Johannes Berg
[not found] ` <1210018214.4181.27.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 20:44 ` David Miller
2008-05-05 20:57 ` Johannes Berg
[not found] ` <1210021066.4181.41.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 21:01 ` David Miller
2008-05-05 22:37 ` David Miller
2008-05-05 22:44 ` Johannes Berg
[not found] ` <1210027447.8012.15.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 23:14 ` David Miller [this message]
[not found] ` <20080505.161458.46071527.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-05 23:23 ` Johannes Berg
[not found] ` <1210029835.8012.30.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 23:39 ` David Miller
[not found] ` <20080505.163916.239187195.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-06 0:01 ` Johannes Berg
[not found] ` <1210032076.8012.49.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-06 0:08 ` David Miller
[not found] ` <20080505.170805.127854312.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-06 11:13 ` Johannes Berg
2008-05-06 1:32 ` Herbert Xu
2008-05-13 5:01 ` David Miller
2008-05-05 23:03 ` David Miller
[not found] ` <20080505.160328.203996832.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-05 23:17 ` Johannes Berg
[not found] ` <1210029435.8012.25.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 23:24 ` David Miller
[not found] ` <20080505.162424.176435653.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-05 23:30 ` Johannes Berg
2008-05-05 23:36 ` Johannes Berg
[not found] ` <1210030591.8012.41.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-05 23:40 ` David Miller
2008-05-13 3:52 ` David Miller
[not found] ` <20080512.205224.12536510.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-05-13 9:01 ` Johannes Berg
[not found] ` <1210669273.3646.51.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org>
2008-05-13 9:45 ` David Miller
2008-05-13 10:07 ` Johannes Berg
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