Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965726AbaDJTRq (ORCPT ); Thu, 10 Apr 2014 15:17:46 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.228]:16390 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965197AbaDJTRo (ORCPT ); Thu, 10 Apr 2014 15:17:44 -0400 Date: Thu, 10 Apr 2014 15:17:41 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: Sebastian Andrzej Siewior , Clark Williams , LKML , linux-rt-users , Mike Galbraith , "Paul E. McKenney" , Paul Gortmaker , Thomas Gleixner , Frederic Weisbecker , Ingo Molnar Subject: Re: [RFC PATCH RT] rwsem: The return of multi-reader PI rwsems Message-ID: <20140410151741.617f86d9@gandalf.local.home> In-Reply-To: <20140410153617.GN10526@twins.programming.kicks-ass.net> References: <20140409151922.5fa5d999@gandalf.local.home> <20140410094430.56ca9ee1@sluggy.gateway.2wire.net> <5346B2C8.6000207@linutronix.de> <20140410153617.GN10526@twins.programming.kicks-ass.net> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 10 Apr 2014 17:36:17 +0200 Peter Zijlstra wrote: > It defaults to the total number of CPUs in the system, given the default > setup (all CPUs in a single balance domain), this should result in all > CPUs working concurrently on the boosted read sides. Unfortunately, it currently defaults to the number of possible CPUs in the system. I should probably move the default assignment to after SMP is setup. Currently it happens in early boot before all the CPUs are running. On boot up, the limit is set to NR_CPUS which should be much higher than what the system has, but shouldn't matter during boot. But after all the CPUs are up and running, it can lower it to online CPUs. I think I'll go and make v3 of this patch. -- Steve -- 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/