From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net (unknown [IPv6:2001:4f8:3:36:211:85ff:fe63:a549]) by huchra.bufferbloat.net (Postfix) with ESMTP id 10BB82005CC for ; Fri, 29 Jun 2012 01:04:31 -0700 (PDT) Received: from localhost (74-93-104-98-Washington.hfc.comcastbusiness.net [74.93.104.98]) by shards.monkeyblade.net (Postfix) with ESMTPSA id 243BE584C86; Fri, 29 Jun 2012 01:04:31 -0700 (PDT) Date: Fri, 29 Jun 2012 01:04:29 -0700 (PDT) Message-Id: <20120629.010429.52786940228506998.davem@davemloft.net> To: eric.dumazet@gmail.com From: David Miller In-Reply-To: <1340949008.29822.73.camel@edumazet-glaptop> References: <1340947448.29822.41.camel@edumazet-glaptop> <20120628.222934.767995619021650710.davem@davemloft.net> <1340949008.29822.73.camel@edumazet-glaptop> X-Mailer: Mew version 6.5 on Emacs 24.0.97 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: nanditad@google.com, netdev@vger.kernel.org, codel@lists.bufferbloat.net, ycheng@google.com, ncardwell@google.com, mattmathis@google.com Subject: Re: [Codel] [PATCH net-next] fq_codel: report congestion notification at enqueue time X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Jun 2012 08:04:31 -0000 From: Eric Dumazet Date: Fri, 29 Jun 2012 07:50:08 +0200 > Hmm, problem is the sender thinks the packet was queued for > transmission. > > ret = macvlan_queue_xmit(skb, dev); > if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { > struct macvlan_pcpu_stats *pcpu_stats; > > pcpu_stats = this_cpu_ptr(vlan->pcpu_stats); > u64_stats_update_begin(&pcpu_stats->syncp); > pcpu_stats->tx_packets++; > pcpu_stats->tx_bytes += len; > u64_stats_update_end(&pcpu_stats->syncp); > } else { > this_cpu_inc(vlan->pcpu_stats->tx_dropped); > } Ok, that is the meaning this has taken on. Same test exists in vlan_dev.c and this test used to be present also in the ipip.h macros some time ago. Nobody really does anything special with this value, except to translate it to a zero 0 when propagating back to sockets. The only thing it guards is the selection of which statistic to increment. For all practical purposes it is treated as NET_XMIT_SUCCESS except in one location, pktgen, where it causes the errors counter to increment. Looking this over, I'd say we should just get rid of it.