From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: ilpo.jarvinen@helsinki.fi, rick.jones2@hp.com,
netdev@vger.kernel.org, therbert@google.com,
ncardwell@google.com, maze@google.com, ycheng@google.com
Subject: Re: [RFC] allow skb->head to point/alias to first skb frag
Date: Thu, 26 Apr 2012 05:18:00 -0400 (EDT) [thread overview]
Message-ID: <20120426.051800.637617874638567499.davem@davemloft.net> (raw)
In-Reply-To: <1335431402.2775.24.camel@edumazet-glaptop>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 26 Apr 2012 11:10:02 +0200
> The 'frag' would have a known size : 2048 bytes
>
> But the end of it would be used by struct skb_shared_info
>
> so data_len would be 0 in fact.
>
> This would look like a regular linear skb.
>
> Just a bit set in skb to say : Warning, skb->head was not kmalloced :
> replace kfree(head) by put_page(...)
>
> And this bit would be tested in GRO or tcp merge to 'upgrade' this
> skb->head to proper page/frag
And what happens if this ends up in a piece of code which wants to
append a page frag?
Or a piece of code which copies an SKB, including page frag parts?
All I'm saying is that the number of tests necessary to make this work
properly might become prohibitive.
next prev parent reply other threads:[~2012-04-26 9:18 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-23 9:38 [PATCH 2/2 net-next] tcp: sk_add_backlog() is too agressive for TCP Eric Dumazet
2012-04-23 17:14 ` Rick Jones
2012-04-23 17:23 ` Eric Dumazet
2012-04-23 20:01 ` David Miller
2012-04-23 20:37 ` Eric Dumazet
2012-04-23 20:57 ` Rick Jones
2012-04-23 21:30 ` Eric Dumazet
2012-04-23 21:51 ` Rick Jones
2012-04-23 21:56 ` Rick Jones
2012-04-23 22:05 ` Eric Dumazet
2012-04-23 22:16 ` Rick Jones
2012-04-24 15:25 ` Christoph Lameter
2012-04-23 21:01 ` David Miller
2012-04-23 21:38 ` Eric Dumazet
2012-04-24 2:20 ` Eric Dumazet
2012-04-24 2:27 ` David Miller
2012-04-24 8:01 ` Ilpo Järvinen
2012-04-24 8:10 ` David Miller
2012-04-24 8:21 ` Ilpo Järvinen
2012-04-24 8:25 ` David Miller
2012-04-24 8:40 ` Ilpo Järvinen
2012-04-24 8:48 ` David Miller
2012-04-24 10:32 ` Ilpo Järvinen
2012-04-24 8:56 ` Eric Dumazet
2012-04-26 8:10 ` [RFC] allow skb->head to point/alias to first skb frag Eric Dumazet
2012-04-26 8:36 ` David Miller
2012-04-26 9:10 ` Eric Dumazet
2012-04-26 9:18 ` David Miller [this message]
2012-04-26 9:22 ` Eric Dumazet
2012-04-26 10:09 ` Maciej Żenczykowski
2012-04-26 12:32 ` Eric Dumazet
2012-04-26 13:50 ` Eric Dumazet
2012-04-26 20:12 ` David Miller
2012-04-26 20:18 ` Eric Dumazet
2012-04-24 8:49 ` [PATCH 2/2 net-next] tcp: sk_add_backlog() is too agressive for TCP Eric Dumazet
2012-04-24 8:44 ` David Laight
2012-04-24 8:53 ` Eric Dumazet
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