From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 013BA6B0038 for ; Fri, 2 Sep 2016 10:04:18 -0400 (EDT) Received: by mail-it0-f70.google.com with SMTP id 192so41360200itm.1 for ; Fri, 02 Sep 2016 07:04:17 -0700 (PDT) Received: from EUR01-HE1-obe.outbound.protection.outlook.com (mail-he1eur01on0086.outbound.protection.outlook.com. [104.47.0.86]) by mx.google.com with ESMTPS id k126si2389404oif.49.2016.09.02.07.04.09 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 02 Sep 2016 07:04:09 -0700 (PDT) Subject: Re: [PATCH v15 04/13] task_isolation: add initial support References: <1471382376-5443-1-git-send-email-cmetcalf@mellanox.com> <1471382376-5443-5-git-send-email-cmetcalf@mellanox.com> <20160829163352.GV10153@twins.programming.kicks-ass.net> <20160830075854.GZ10153@twins.programming.kicks-ass.net> <20160901100631.GQ10153@twins.programming.kicks-ass.net> From: Chris Metcalf Message-ID: Date: Fri, 2 Sep 2016 10:03:52 -0400 MIME-Version: 1.0 In-Reply-To: <20160901100631.GQ10153@twins.programming.kicks-ass.net> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Gilad Ben Yossef , Steven Rostedt , Ingo Molnar , Andrew Morton , Rik van Riel , Tejun Heo , Frederic Weisbecker , Thomas Gleixner , "Paul E. McKenney" , Christoph Lameter , Viresh Kumar , Catalin Marinas , Will Deacon , Andy Lutomirski , Michal Hocko , linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org On 9/1/2016 6:06 AM, Peter Zijlstra wrote: > On Tue, Aug 30, 2016 at 11:32:16AM -0400, Chris Metcalf wrote: >> On 8/30/2016 3:58 AM, Peter Zijlstra wrote: >>> What !? I really don't get this, what are you waiting for? Why is >>> rescheduling making things better. >> We need to wait for the last dyntick to fire before we can return to >> userspace. There are plenty of options as to what we can do in the >> meanwhile. > Why not keep your _TIF_TASK_ISOLATION_FOO flag set and re-enter the > loop? > > I really don't see how setting TIF_NEED_RESCHED is helping anything. Yes, I think I addressed that in an earlier reply to Frederic; and you're right, I don't think TIF_NEED_RESCHED or schedule() are the way to go. https://lkml.kernel.org/g/107bd666-dbcf-7fa5-ff9c-f79358899712@mellanox.com Any thoughts on the question of "just re-enter the loop" vs. schedule_timeout()? -- Chris Metcalf, Mellanox Technologies http://www.mellanox.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org