From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH v2 net-next] tcp: avoid tx starvation by SYNACK packets Date: Wed, 27 Jun 2012 10:45:10 +0200 Message-ID: <1340786710.26242.37.camel@edumazet-glaptop> References: <201206260734.33472.hans.schillstrom@ericsson.com> <1340730156.10893.359.camel@edumazet-glaptop> <1340778733.2028.110.camel@localhost> <20120626.235423.588696200884989114.davem@davemloft.net> <1340781845.2028.133.camel@localhost> <1340782216.10893.427.camel@edumazet-glaptop> <1340783670.2028.141.camel@localhost> <1340784137.26242.5.camel@edumazet-glaptop> <1340785275.2028.151.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: David Miller , hans.schillstrom@ericsson.com, subramanian.vijay@gmail.com, dave.taht@gmail.com, netdev@vger.kernel.org, ncardwell@google.com, therbert@google.com, mph@hoth.dk To: Jesper Dangaard Brouer Return-path: Received: from mail-ee0-f46.google.com ([74.125.83.46]:62096 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752460Ab2F0IpR (ORCPT ); Wed, 27 Jun 2012 04:45:17 -0400 Received: by eeit10 with SMTP id t10so239963eei.19 for ; Wed, 27 Jun 2012 01:45:16 -0700 (PDT) In-Reply-To: <1340785275.2028.151.camel@localhost> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2012-06-27 at 10:21 +0200, Jesper Dangaard Brouer wrote: > It works because we have a spinlock problem in the code... Perhaps, they > did it, because we have have locking/contention problem, not the other > way around ;-) How about fixing the code instead? ;-))) The socket lock is currently mandatory. It's really _hard_ to remove it, your attempts added a lot of races. I want to do it properly, adding needed RCU and array of spinlocks were appropriate. Hopefully, its easier than the RCU conversion I did for the lookups of ESTABLISHED/TIMEWAIT sockets.