From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941443AbcIVWAE (ORCPT ); Thu, 22 Sep 2016 18:00:04 -0400 Received: from mail-bl2nam02on0122.outbound.protection.outlook.com ([104.47.38.122]:48736 "EHLO NAM02-BL2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S941432AbcIVV7z (ORCPT ); Thu, 22 Sep 2016 17:59:55 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=waiman.long@hpe.com; Message-ID: <57E45438.2010307@hpe.com> Date: Thu, 22 Sep 2016 17:59:20 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Thomas Gleixner CC: Davidlohr Bueso , Peter Zijlstra , Mike Galbraith , Ingo Molnar , Jonathan Corbet , , , Jason Low , Scott J Norton , Douglas Hatch Subject: Re: [RFC PATCH v2 3/5] futex: Throughput-optimized (TO) futexes References: <1474378963-15496-4-git-send-email-Waiman.Long@hpe.com> <1474441172.27308.19.camel@gmail.com> <57E319BE.2050208@hpe.com> <20160922074932.GV5008@twins.programming.kicks-ass.net> <20160922144123.GB13358@linux-80c1.suse> <20160922151144.GC13358@linux-80c1.suse> <57E43A46.9080601@hpe.com> <57E43EF9.8000400@hpe.com> <20160922213921.GA30291@linux-80c1.suse> In-Reply-To: Content-Type: text/plain; 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If so I can resend the patches from a while ago. > Certainly yes. My faint memory tells me that there was some potential issue > due to boosting the owner only if it gets scheduled out, but I might be > wrong. It is tricky to add optimistic spinning to rtmutexes because of the need to observe process priorities. It is certainly possible to make the top waiter spin, but then I am not sure how much performance gain with just that. Cheers, Longman