From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752423AbcGSBtr (ORCPT ); Mon, 18 Jul 2016 21:49:47 -0400 Received: from mga04.intel.com ([192.55.52.120]:25842 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbcGSBto convert rfc822-to-8bit (ORCPT ); Mon, 18 Jul 2016 21:49:44 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,387,1464678000"; d="scan'208";a="1009435878" From: "Liang, Kan" To: Hannes Frederic Sowa , Andi Kleen CC: Florian Westphal , "davem@davemloft.net" , "linux-kernel@vger.kernel.org" , "intel-wired-lan@lists.osuosl.org" , "netdev@vger.kernel.org" , "Kirsher, Jeffrey T" , "mingo@redhat.com" , "peterz@infradead.org" , "kuznet@ms2.inr.ac.ru" , "jmorris@namei.org" , "yoshfuji@linux-ipv6.org" , "kaber@trash.net" , "akpm@linux-foundation.org" , "keescook@chromium.org" , "viro@zeniv.linux.org.uk" , "gorcunov@openvz.org" , "john.stultz@linaro.org" , "aduyck@mirantis.com" , "ben@decadent.org.uk" , "decot@googlers.com" , "Brandeburg, Jesse" Subject: RE: [RFC PATCH 00/30] Kernel NET policy Thread-Topic: [RFC PATCH 00/30] Kernel NET policy Thread-Index: AQHR4QAYnLk7kPdiS0Cr9oejSYLaHaAdxziAgAAHaACAADevAIAACwaAgAAjkACAAMKigA== Date: Tue, 19 Jul 2016 01:49:41 +0000 Message-ID: <37D7C6CF3E00A74B8858931C1DB2F07712C19A4A@SHSMSX103.ccr.corp.intel.com> References: <1468824984-65318-1-git-send-email-kan.liang@intel.com> <20160718151841.GA19066@breakpoint.cc> <20160718154512.GK5871@two.firstfloor.org> <7a03a353-4c1e-2bb4-2550-f84fc4cc79ac@stressinduktion.org> <20160718194357.GL5871@two.firstfloor.org> <1468878674.1778899.669950273.69750E32@webmail.messagingengine.com> In-Reply-To: <1468878674.1778899.669950273.69750E32@webmail.messagingengine.com> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiMGJkNmRjMGUtZGM0Mi00ZGQ0LWFmMzYtYzlmNzU5YTc0ZWVlIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IkVcLzJIdVM4NGVDelk2b1wvTEwwTVU4NE95Q2RcL1dtcHl1TGtsVzRMUzF6OXc9In0= x-ctpclassification: CTP_IC x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > > Also of course it would be fundamentally less efficient than kernel > > code doing that, just because of the additional context switches > > needed. > > Synchronizing or configuring any kind of queues already requires rtnl_mutex. > I didn't test it but acquiring rtnl mutex in inet_recvmsg is unlikely to fly > performance wise and Yes, rtnl will bring some overheads. But the configuration is one time thing for application or socket. It only happens on receiving first packet. Unless the application/socket only transmit few packets, the overhead could be ignored. If they only transmit few packets, why they care about performance? > might even be very dangerous under DoS attacks (like > I see in 24/30). > Patch 29/30 tries to prevent such case. Thanks, Kan