From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Metcalf Subject: Re: [PATCH v15 04/13] task_isolation: add initial support Date: Fri, 2 Sep 2016 10:03:52 -0400 Message-ID: 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> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160901100631.GQ10153@twins.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org 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 List-Id: linux-api@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