From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] tcp: avoid wakeups for pure ACK Date: Wed, 27 Feb 2013 13:04:44 -0500 (EST) Message-ID: <20130227.130444.2188252064827683663.davem@davemloft.net> References: <1361984703.11403.43.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, ncardwell@google.com, therbert@google.com, ycheng@google.com, ak@linux.intel.com To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:58296 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758009Ab3B0SEr (ORCPT ); Wed, 27 Feb 2013 13:04:47 -0500 In-Reply-To: <1361984703.11403.43.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Wed, 27 Feb 2013 09:05:03 -0800 > Processing pure ACK on behalf of the thread blocked in tcp_recvmsg() > is a waste of resources, as thread has to immediately sleep again > because it got no payload. More than one thread can be operating on the socket, the other one could be waiting for the window to open up in order to do a send. Are you absolutely sure that we won't have a problem in that situation? In fact I wonder if that does the right thing right now.