From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [RFC][PATCH 4/5] I/OAT DMA support and TCP acceleration Date: Wed, 21 Dec 2005 07:20:43 +0100 Message-ID: <43A8F43B.6020307@cosmosbay.com> References: <1135142263.13781.21.camel@cleech-mobl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: lkml , netdev , "Grover, Andrew" , "Ronciak, John" Return-path: To: Chris Leech In-Reply-To: <1135142263.13781.21.camel@cleech-mobl> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Chris Leech a =E9crit : > Structure changes for TCP recv offload to I/OAT >=20 > Adds an async_wait_queue and some additional fields to tcp_sock, a > copied_early flag to sb_buff and a dma_cookie_t to tcp_skb_cb >=20 > Renames cleanup_rbuf to tcp_cleanup_rbuf and makes it non-static so w= e > can call it from tcp_input.c=20 >=20 > ---=20 > include/linux/skbuff.h | 5 +++-- > include/linux/tcp.h | 9 +++++++++ > include/net/tcp.h | 10 ++++++++++ > net/core/skbuff.c | 1 + > net/ipv4/tcp.c | 11 ++++++----- > net/ipv4/tcp_ipv4.c | 4 ++++ > net/ipv4/tcp_minisocks.c | 1 + > net/ipv6/tcp_ipv6.c | 1 + > 8 files changed, 35 insertions(+), 7 deletions(-) > diff -urp a/include/linux/skbuff.h b/include/linux/skbuff.h > --- a/include/linux/skbuff.h 2005-12-21 12:05:09.000000000 -0800 > +++ b/include/linux/skbuff.h 2005-12-21 12:10:14.000000000 -0800 > @@ -248,7 +248,7 @@ struct sk_buff { > * want to keep them across layers you have to do a skb_clone() > * first. This is owned by whoever has the skb queued ATM. > */ > - char cb[40]; > + char cb[44]; Hi Chris Please consider not enlarging cb[] if not CONFIG_NET_DMA ? I mean, most machines wont have a compatable NIC, so why should they pa= y the=20 price (memory, cpu) in a critical structure named sk_buff ? #ifdef CONFIG_NET_DMA typedef dma_cookie_t net_dma_cookie_t; #else typedef struct {} net_dma_cookie_t; #endif =2E.. char cb[40+sizeof(net_dma_cookie_t)]; Same remark apply for the rest of your patch : Please consider to make = added=20 fields and code conditional to CONFIG_NET_DMA Eric