From: Mathias Krause <mathias.krause@secunet.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>,
Steffen Klassert <steffen.klassert@secunet.com>,
Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>,
netdev@vger.kernel.org
Subject: Re: [PATCH net-next 3/3] net: allow to leave the buffer fragmented in skb_cow_data()
Date: Wed, 06 Nov 2013 10:49:18 +0100 [thread overview]
Message-ID: <527A109E.5040000@secunet.com> (raw)
In-Reply-To: <20131106093028.GA18435@gondor.apana.org.au>
On 06.11.2013 10:30, Herbert Xu wrote:
> On Tue, Nov 05, 2013 at 02:54:11PM +0100, Mathias Krause wrote:
>> - /* If skb is cloned or its head is paged, reallocate
>> - * head pulling out all the pages (pages are considered not writable
>> - * at the moment even if they are anonymous).
>> + /* If skb is cloned reallocate head pulling out all the pages (pages are
>> + * considered not writable at the moment even if they are anonymous).
>> */
>
> Hang on, you haven't explained why it is OK to write to pages.
Why wouldn't it if the skb isn't cloned?
> What if said page is owned by the virt host or some app?
How would one detect such a case. I could image not by testing
skb_shinfo(skb)->nr_frags as it is right now?
Regards,
Mathias
next prev parent reply other threads:[~2013-11-06 9:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-05 13:54 [PATCH net-next 0/3] IPsec improvements Mathias Krause
2013-11-05 13:54 ` [PATCH net-next 1/3] net: move pskb_put() to core code Mathias Krause
2013-11-05 18:33 ` Ben Hutchings
2013-11-06 9:01 ` Mathias Krause
2013-11-05 13:54 ` [PATCH net-next 2/3] caif: use pskb_put() instead of reimplementing its functionality Mathias Krause
2013-11-05 13:54 ` [PATCH net-next 3/3] net: allow to leave the buffer fragmented in skb_cow_data() Mathias Krause
2013-11-05 14:33 ` Eric Dumazet
2013-11-05 14:43 ` Mathias Krause
2013-11-06 9:30 ` Herbert Xu
2013-11-06 9:49 ` Mathias Krause [this message]
2013-11-06 9:52 ` Herbert Xu
2013-11-06 12:42 ` Mathias Krause
2013-11-06 12:48 ` Herbert Xu
2013-11-06 16:39 ` Eric Dumazet
2013-11-07 8:56 ` Mathias Krause
2013-11-07 8:55 ` Mathias Krause
2013-11-07 9:01 ` Herbert Xu
2013-11-07 10:01 ` Mathias Krause
2013-11-06 4:48 ` [PATCH net-next 0/3] IPsec improvements David Miller
2013-11-06 9:02 ` Mathias Krause
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