Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752641AbbDTRbX (ORCPT ); Mon, 20 Apr 2015 13:31:23 -0400 Received: from cantor2.suse.de ([195.135.220.15]:48953 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255AbbDTRbW (ORCPT ); Mon, 20 Apr 2015 13:31:22 -0400 Message-ID: <1429551065.2042.14.camel@stgolabs.net> Subject: Re: [PATCH 2/2] futex: lockless wakeups From: Davidlohr Bueso To: Peter Zijlstra Cc: Ingo Molnar , Thomas Gleixner , Ingo Molnar , Sebastian Andrzej Siewior , Linus Torvalds , Chris Mason , Steven Rostedt , fredrik.markstrom@windriver.com, linux-kernel@vger.kernel.org, Andrew Morton Date: Mon, 20 Apr 2015 10:31:05 -0700 In-Reply-To: <20150420145730.GY27490@worktop.programming.kicks-ass.net> References: <1429471060-21271-1-git-send-email-dave@stgolabs.net> <1429471060-21271-3-git-send-email-dave@stgolabs.net> <20150420061836.GA11191@gmail.com> <1429538139.2042.10.camel@stgolabs.net> <20150420145730.GY27490@worktop.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1105 Lines: 28 On Mon, 2015-04-20 at 16:57 +0200, Peter Zijlstra wrote: > Haha, you dug that out did you ;-) > > Does this patch on its own actually help anything? Back when I wrote > that there was the vague hope it would actually help some of the > client-server ping-pong workloads, where the client does sync requests > to the server. > > In that case, if the server can handle the req. while the client yields > we've saved on an expensive wakeup. > > Reality never really worked out for that -- even after we fixed a few > boot and runtime issues with it. I had boot problems about 2 years ago (even with qemu) with it. Nowadays, I cannot trigger any issues with it. And on a large machine I've been using it just fine, throwing a lot of workloads at it. All in all my schedule auditing has only been by searching the code, not from this patch. Thanks, Davidlohr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/