From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934978AbbI2Rf2 (ORCPT ); Tue, 29 Sep 2015 13:35:28 -0400 Received: from mail-db3on0065.outbound.protection.outlook.com ([157.55.234.65]:28576 "EHLO emea01-db3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932398AbbI2RfT (ORCPT ); Tue, 29 Sep 2015 13:35:19 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=cmetcalf@ezchip.com; Subject: Re: [PATCH v7 05/11] task_isolation: add debug boot flag To: Andy Lutomirski References: <1443453446-7827-1-git-send-email-cmetcalf@ezchip.com> <1443453446-7827-6-git-send-email-cmetcalf@ezchip.com> <5609B75B.9040204@ezchip.com> CC: Gilad Ben Yossef , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Andrew Morton , Rik van Riel , Tejun Heo , Frederic Weisbecker , Thomas Gleixner , "Paul E. McKenney" , Christoph Lameter , Viresh Kumar , Catalin Marinas , Will Deacon , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" From: Chris Metcalf Message-ID: <560ACBC5.3090301@ezchip.com> Date: Tue, 29 Sep 2015 13:35:01 -0400 User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [12.216.194.146] X-ClientProxiedBy: BLUPR0101CA0014.prod.exchangelabs.com (25.163.116.152) To HE1PR02MB0778.eurprd02.prod.outlook.com (25.161.118.142) X-Microsoft-Exchange-Diagnostics: 1;HE1PR02MB0778;2:GvugwsSGr3ut9UlSKw4UgwO1ceNYSKIs97VxVeJ7FKybuOcDBMSjR75C6Zo5lXXmzX7DVJPUZ+S7Mp9+/Em4A7DR8Mbvedkkrar4IQRTPJRhD3vGMTFKNxoE5+d771btYz9Hn5iWor4TRK6edFPDo/4OBMHRKeC7WeVNe68QVck=;3:2JtCtoVAnIU3g66sL3mkRbcOwocLTHvznvhcIAlEnrKNdsLqmQlgBa83tHp/JKTKIT7xQ/OUn66jR3wfOlth/ldvJ6+Kp7E7H9d22VDhabPgUncITMEf/4+yryD2gi88h3QbOrqtoe0x34j+BM70LA==;25:jq0lF8p8cHqWHJbnLarZcdi/YKFePNrKatdFVemBG59uREOEmV9VH42eASGAkLFG24QtYxbQ5D/pxdc+gN37xClcXLKOnlP7MfAkaWTXhrzQKql2HwzPwiZJYsHD5Qa4bntOGMelUQKw4Z9x1XBfWY3TFHfB19kj244D6KWVY4WDUv8CPkeebR3RRkluwMx5gNzVJx+I69gqJszOQ9QNgnkf3mPdHxHxMJvq7qbIJEYukOTrOrsS+hvfiZT7vR5v3HwH2OBFkoAnwEnLG3j7GA==;20:XAxztjXvXThXCtQsEtnJ2tu0Wlok34pcMBw5ylxXTyRX26kR74+SnNQiS9T616Dhhrgq6s0ksBcQdR9PFKaVvfoZl1yoU3+DSgsa7NW1Yc4sN6k4UGUU0hp/8HBFvvs0gzuVZzFA5ISxZVJ9PPPY9VPd7G5GeU6Iwp/c8nWHoH4= X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:HE1PR02MB0778; 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Maybe just failing the prctl would be enough. If > someone turns on the prctl and then changes their affinity, maybe we > should treat it as though they're just asking for trouble and allow > it. Yes, the original Tilera implementation required the task to be affinitized to a single, nohz_full cpu before you could call the prctl() successfully. I think I will re-instate that for the patch series, and if the user then re-affinitizes to a non-nohz_full core later, well, "don't do that then". -- Chris Metcalf, EZChip Semiconductor http://www.ezchip.com