From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: Re: [PATCH 00/14]: netlink: memory mapped I/O Date: Wed, 17 Apr 2013 21:40:46 +0200 Message-ID: <20130417194046.GF1408@breakpoint.cc> References: <1366217229-22705-1-git-send-email-kaber@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org To: Patrick McHardy Return-path: Content-Disposition: inline In-Reply-To: <1366217229-22705-1-git-send-email-kaber@trash.net> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org Patrick McHardy wrote: > The following patches contain an implementation of memory mapped I/O for > netlink. The implementation is modelled after AF_PACKET memory mapped I/O > with a few differences: [..] > Following are some numbers collected by Florian Westphal based on a > slightly older version, which included an experimental patch for the > nfnetlink_queue ordering issue. I'd like to see a comparision with Eric Dumazets nfnetlink_queue zerocopy patch [ ae08ce0021087a5d812d2714fb2a326ef9f8c450, netfilter: nfnetlink_queue: zero copy support ]. The nice thing about that patch is its transparency to userspace, and the avoidance of the 'nfnetlink_queue packet reordering' issue. Sorry :) Another issue with mmap is the need to preallocate the ring frame size. After the gso avoidance change [ no skb_gso_segment calls anymore ], we will need to be able to queue GSO/GRO skbs, which makes it necessary to cope with 64k payload in the mmap case... Cheers, Florian