From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: Re: [PATCH net-next RFC 1/5] net-timestamp: no-payload option Date: Fri, 9 Jan 2015 14:47:57 -0500 Message-ID: References: <1420824719-28848-1-git-send-email-willemb@google.com> <1420824719-28848-2-git-send-email-willemb@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Network Development , "David S. Miller" , Richard Cochran , Eric Dumazet To: Andy Lutomirski Return-path: Received: from mail-qa0-f54.google.com ([209.85.216.54]:62587 "EHLO mail-qa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbbAITs2 (ORCPT ); Fri, 9 Jan 2015 14:48:28 -0500 Received: by mail-qa0-f54.google.com with SMTP id i13so8471124qae.13 for ; Fri, 09 Jan 2015 11:48:28 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Jan 9, 2015 at 2:43 PM, Andy Lutomirski wrote: > On Fri, Jan 9, 2015 at 9:31 AM, Willem de Bruijn wrote: >> From: Willem de Bruijn >> >> Add timestamping option SOF_TIMESTAMPING_OPT_TSONLY. For transmit >> timestamps, this loops timestamps on top of empty packets. >> >> Doing so reduces the pressure on SO_RCVBUF. Payload inspection and >> cmsg reception (aside from timestamps) are no longer possible. This >> works together with a follow on patch that allows administrators to >> only allow tx timestamping if it does not loop payload or metadata. > > If this loses IP_PKTINFO, that will be a bit unfortunate. > If it doesn't, then we might as well loop the entire payload. For applications that need pktinfo or other cmsg, do not select the option.