From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH net-next] sock: don't enable netstamp for af_unix sockets Date: Tue, 27 Oct 2015 14:44:28 +0100 Message-ID: <1445953468.1370159.421485969.5DA0A8B3@webmail.messagingengine.com> References: <1445863897-22646-1-git-send-email-hannes@stressinduktion.org> <20151026131928.GA1820@netboy> <1445866379.133031.420389177.3AE9E175@webmail.messagingengine.com> <20151027101157.GA1850@netboy> <1445944161.1336457.421364569.5449BCCB@webmail.messagingengine.com> <1445944516.1337466.421368457.2463FECE@webmail.messagingengine.com> <1445951975.7476.16.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Richard Cochran , netdev@vger.kernel.org, Jesper Dangaard Brouer To: Eric Dumazet Return-path: Received: from out4-smtp.messagingengine.com ([66.111.4.28]:50408 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932203AbbJ0No3 (ORCPT ); Tue, 27 Oct 2015 09:44:29 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id DEBDD20D45 for ; Tue, 27 Oct 2015 09:44:28 -0400 (EDT) In-Reply-To: <1445951975.7476.16.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Oct 27, 2015, at 14:19, Eric Dumazet wrote: > On Tue, 2015-10-27 at 12:15 +0100, Hannes Frederic Sowa wrote: > > > Also counter question: why is the netstamp code protected by a > > static_key otherwise if not for trying to suppress the code path as > > often as possible if not used? ;) > > Any idea of why timestamping is asked on AF_UNIX in the first place ? I guess syslog code want's to have more accurate timetstamps on when the packet is send. > For messages sent/received on af_unix sockets, in which place timestamp > is taken ? in unix_sendmsg on the sending unix socket (we check peer unix socket for timestamp flag). > Is it at the time skb is cooked and stored in receive queue, or the time > it was dequeued ? No, at time it is send by sendmsg on the sending socket. > In any case, is your patch changing af_unix behavior ? It is not clear > from your changelog... No, af_unix logic does not pass this logic at all, so we don't need to care about netstamp code. netstamp_needed is private to dev.c. Bye, Hannes