From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v3 net-next 0/4] tcp: take a bit more care of backlog stress Date: Fri, 30 Nov 2018 13:27:47 -0800 (PST) Message-ID: <20181130.132747.799494882078145665.davem@davemloft.net> References: <20181127224203.69999-1-edumazet@google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jean-louis@dupond.be, ncardwell@google.com, ycheng@google.com, eric.dumazet@gmail.com To: edumazet@google.com Return-path: Received: from shards.monkeyblade.net ([23.128.96.9]:60222 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725749AbeLAIi0 (ORCPT ); Sat, 1 Dec 2018 03:38:26 -0500 In-Reply-To: <20181127224203.69999-1-edumazet@google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Tue, 27 Nov 2018 14:41:59 -0800 > While working on the SACK compression issue Jean-Louis Dupond > reported, we found that his linux box was suffering very hard > from tail drops on the socket backlog queue. > > First patch hints the compiler about sack flows being the norm. > > Second patch changes non-sack code in preparation of the ack > compression. > > Third patch fixes tcp_space() to take backlog into account. > > Fourth patch is attempting coalescing when a new packet must > be added to the backlog queue. Cooking bigger skbs helps > to keep backlog list smaller and speeds its handling when > user thread finally releases the socket lock. > > v3: Neal/Yuchung feedback addressed : > Do not aggregate if any skb has URG bit set. > Do not aggregate if the skbs have different ECE/CWR bits > > v2: added feedback from Neal : tcp: take care of compressed acks in tcp_add_reno_sack() > added : tcp: hint compiler about sack flows > added : tcp: make tcp_space() aware of socket backlog Series applied, thanks Eric. I'll push this out after the build check finishes.