From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] gro: introduce gro_mac_header_len Date: Mon, 06 Feb 2012 11:31:45 -0500 (EST) Message-ID: <20120206.113145.1284864994961472499.davem@davemloft.net> References: <1328541706.2220.50.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <4F2FF050.7040400@mellanox.com> <1328545627.2220.72.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, herbert-F6s6mLieUQo7FNHlEwC/lvQIK84fMopw@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shlomop-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: eric.dumazet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Return-path: In-Reply-To: <1328545627.2220.72.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org From: Eric Dumazet Date: Mon, 06 Feb 2012 17:27:07 +0100 > Shlomo Pongratz reported GRO L2 header check was suited for Ethernet > only, and failed on IB/ipoib traffic. > > He provided a patch faking a zeroed header to let GRO aggregates frames. > > Roland Dreier, Herbert Xu, and others suggested we change GRO L2 header > check to be more generic. > > This patch introduces a new netdevice field, gro_mac_header_len, giving > L2 header length, default to ETH_HLEN (14 bytes) > > A device setup function can override this default value. > > __napi_gro_receive() has special handling for the common case (Ethernet) > to avoid a memcmp() call and use an inline optimized function instead. > > Signed-off-by: Eric Dumazet > Reported-by: Shlomo Pongratz We really need an explanation, probably both in the commit message and the comments next to this new struct member, explaining why in the world we can't use ->hard_header_len for this. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html