From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Cochran Subject: Re: [PATCH] net-packet: tx timestamping on tpacket ring Date: Sun, 14 Apr 2013 15:07:26 +0200 Message-ID: <20130414130726.GB2871@netboy> References: <1365879412-9541-1-git-send-email-willemb@google.com> <5169D9C8.8010504@redhat.com> <516A8A60.5020003@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Willem de Bruijn , Paul Chavent , Eric Dumazet , daniel.borkmann@tik.ee.ethz.ch, xemul@parallels.com, ebiederm@xmission.com, netdev@vger.kernel.org To: Daniel Borkmann Return-path: Received: from mail-ea0-f177.google.com ([209.85.215.177]:55800 "EHLO mail-ea0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751869Ab3DNNHk (ORCPT ); Sun, 14 Apr 2013 09:07:40 -0400 Received: by mail-ea0-f177.google.com with SMTP id q14so1789355eaj.8 for ; Sun, 14 Apr 2013 06:07:39 -0700 (PDT) Content-Disposition: inline In-Reply-To: <516A8A60.5020003@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, Apr 14, 2013 at 12:52:16PM +0200, Daniel Borkmann wrote: > > While going a bit more through the code, I'm wondering .. if we want to support > TX timestamps, could we also support SW _and_ HW timestamps e.g. similar as in > sock_recv_timestamp()? I'm asking, because we already allow setting the flags > for it via sock_tx_timestamp(). This might be good, if possible. And while you are at it, you could also fix the receive code. As it stand now, it is fairly useless, since there is no way for user space to tell which kind of time stamp has been reported. In fact, the code will silently intermingle hardware and software time stamps. That is surely a mean trick to play on the users. Thanks, Richard