Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752942AbdIRIvL convert rfc822-to-8bit (ORCPT ); Mon, 18 Sep 2017 04:51:11 -0400 Received: from us-smtp-delivery-107.mimecast.com ([216.205.24.107]:41173 "EHLO us-smtp-delivery-107.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752920AbdIRIvI (ORCPT ); Mon, 18 Sep 2017 04:51:08 -0400 Subject: Re: [PATCH v3] irqchip/tango: Don't use incorrect irq_mask_ack callback From: Marc Gonzalez To: Marc Zyngier , Thomas Gleixner , Jason Cooper CC: Florian Fainelli , Doug Berger , Mans Rullgard , Mason , LKML , Linux ARM , Thibaud Cornic References: <20170719190734.18566-1-opendmb@gmail.com> <20170719190734.18566-3-opendmb@gmail.com> <7a51555f-8191-9ebd-1f30-7c20f6db9d3f@sigmadesigns.com> <8d29fec9-35b8-c33b-3091-3e9a51c99ed7@gmail.com> <6f0092f7-692f-4a15-1d95-40f4e59c8585@sigmadesigns.com> <3b858e14-0da1-d4aa-eb84-f136ece8c2a6@gmail.com> <48734beb-0e6b-3a8f-ebf4-b1cec63322e5@gmail.com> Message-ID: Date: Mon, 18 Sep 2017 10:49:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0 SeaMonkey/2.49.1 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [172.27.0.114] X-MC-Unique: b9KuX0cnOIa1tHmTrx0jSA-1 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4644 Lines: 81 On 21/08/2017 15:25, Marc Gonzalez wrote: > Using separate mask and ack functions (i.e. my patch) > > # iperf3 -c 172.27.64.110 -t 20 > Connecting to host 172.27.64.110, port 5201 > [ 4] local 172.27.64.1 port 40868 connected to 172.27.64.110 port 5201 > [ ID] Interval Transfer Bandwidth Retr Cwnd > [ 4] 0.00-1.00 sec 106 MBytes 888 Mbits/sec 18 324 KBytes > [ 4] 1.00-2.00 sec 106 MBytes 885 Mbits/sec 0 361 KBytes > [ 4] 2.00-3.00 sec 105 MBytes 883 Mbits/sec 4 279 KBytes > [ 4] 3.00-4.00 sec 106 MBytes 890 Mbits/sec 0 300 KBytes > [ 4] 4.00-5.00 sec 106 MBytes 887 Mbits/sec 0 310 KBytes > [ 4] 5.00-6.00 sec 105 MBytes 883 Mbits/sec 0 315 KBytes > [ 4] 6.00-7.00 sec 105 MBytes 885 Mbits/sec 0 321 KBytes > [ 4] 7.00-8.00 sec 105 MBytes 880 Mbits/sec 0 325 KBytes > [ 4] 8.00-9.00 sec 106 MBytes 888 Mbits/sec 0 329 KBytes > [ 4] 9.00-10.00 sec 106 MBytes 886 Mbits/sec 0 335 KBytes > [ 4] 10.00-11.00 sec 105 MBytes 885 Mbits/sec 0 351 KBytes > [ 4] 11.00-12.00 sec 106 MBytes 887 Mbits/sec 1 276 KBytes > [ 4] 12.00-13.00 sec 106 MBytes 885 Mbits/sec 0 321 KBytes > [ 4] 13.00-14.00 sec 105 MBytes 883 Mbits/sec 0 349 KBytes > [ 4] 14.00-15.00 sec 106 MBytes 890 Mbits/sec 0 366 KBytes > [ 4] 15.00-16.00 sec 106 MBytes 888 Mbits/sec 2 286 KBytes > [ 4] 16.00-17.00 sec 105 MBytes 884 Mbits/sec 0 303 KBytes > [ 4] 17.00-18.00 sec 105 MBytes 883 Mbits/sec 0 311 KBytes > [ 4] 18.00-19.00 sec 105 MBytes 880 Mbits/sec 0 315 KBytes > [ 4] 19.00-20.00 sec 106 MBytes 890 Mbits/sec 0 321 KBytes > - - - - - - - - - - - - - - - - - - - - - - - - - > [ ID] Interval Transfer Bandwidth Retr > [ 4] 0.00-20.00 sec 2.06 GBytes 885 Mbits/sec 25 sender > > > Using combined mask and ack functions (i.e. Doug's patch) > > # iperf3 -c 172.27.64.110 -t 20 > Connecting to host 172.27.64.110, port 5201 > [ 4] local 172.27.64.1 port 41235 connected to 172.27.64.110 port 5201 > [ ID] Interval Transfer Bandwidth Retr Cwnd > [ 4] 0.00-1.00 sec 107 MBytes 897 Mbits/sec 60 324 KBytes > [ 4] 1.00-2.00 sec 107 MBytes 898 Mbits/sec 0 361 KBytes > [ 4] 2.00-3.00 sec 107 MBytes 898 Mbits/sec 39 194 KBytes > [ 4] 3.00-4.00 sec 107 MBytes 895 Mbits/sec 0 214 KBytes > [ 4] 4.00-5.00 sec 107 MBytes 901 Mbits/sec 0 223 KBytes > [ 4] 5.00-6.00 sec 108 MBytes 902 Mbits/sec 0 230 KBytes > [ 4] 6.00-7.00 sec 107 MBytes 895 Mbits/sec 0 242 KBytes > [ 4] 7.00-8.00 sec 107 MBytes 901 Mbits/sec 0 253 KBytes > [ 4] 8.00-9.00 sec 107 MBytes 899 Mbits/sec 0 264 KBytes > [ 4] 9.00-10.00 sec 108 MBytes 903 Mbits/sec 0 276 KBytes > [ 4] 10.00-11.00 sec 108 MBytes 902 Mbits/sec 0 286 KBytes > [ 4] 11.00-12.00 sec 107 MBytes 899 Mbits/sec 0 300 KBytes > [ 4] 12.00-13.00 sec 107 MBytes 898 Mbits/sec 33 247 KBytes > [ 4] 13.00-14.00 sec 107 MBytes 900 Mbits/sec 0 294 KBytes > [ 4] 14.00-15.00 sec 107 MBytes 900 Mbits/sec 0 325 KBytes > [ 4] 15.00-16.00 sec 107 MBytes 899 Mbits/sec 0 342 KBytes > [ 4] 16.00-17.00 sec 107 MBytes 898 Mbits/sec 0 351 KBytes > [ 4] 17.00-18.00 sec 108 MBytes 902 Mbits/sec 0 355 KBytes > [ 4] 18.00-19.00 sec 107 MBytes 901 Mbits/sec 0 359 KBytes > [ 4] 19.00-20.00 sec 108 MBytes 903 Mbits/sec 32 255 KBytes > - - - - - - - - - - - - - - - - - - - - - - - - - > [ ID] Interval Transfer Bandwidth Retr > [ 4] 0.00-20.00 sec 2.09 GBytes 900 Mbits/sec 164 sender > > > Ergo, it seems that the performance improvement of the combined > implementation is approximately 1.5% for a load generating ~80k > interrupts per second. Hello irqchip maintainers, As mentioned upthread, there is a bug in drivers/irqchip/irq-tango.c caused by the unexpected implementation of irq_gc_mask_disable_reg_and_ack() That bug can be fixed either by using an appropriate irq_mask_ack callback, or by not defining an irq_mask_ack callback at all. The first option provides ~1.5% more throughput than the second, for a typical use-case. Whichever option you favor, can we fix this bug in current and stable branches? (The fix was submitted two months ago.) Regards.