Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756128Ab2FNOr4 (ORCPT ); Thu, 14 Jun 2012 10:47:56 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:56669 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753835Ab2FNOry (ORCPT ); Thu, 14 Jun 2012 10:47:54 -0400 Date: Thu, 14 Jun 2012 07:47:34 -0700 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Thomas Gleixner , LKML , Ingo Molnar , "Srivatsa S. Bhat" , Rusty Russell , Tejun Heo Subject: Re: [RFC patch 2/5] smpboot: Provide infrastructure for percpu hotplug threads Message-ID: <20120614144734.GA2458@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20120613102823.373180763@linutronix.de> <20120613105815.206105518@linutronix.de> <20120613185748.GF2427@linux.vnet.ibm.com> <20120613191745.GG2427@linux.vnet.ibm.com> <20120613204725.GA9858@linux.vnet.ibm.com> <20120614045125.GA30257@linux.vnet.ibm.com> <20120614125939.GC2443@linux.vnet.ibm.com> <1339678887.2559.30.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1339678887.2559.30.camel@twins> User-Agent: Mutt/1.5.21 (2010-09-15) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12061414-2398-0000-0000-0000077EE3B9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 622 Lines: 17 On Thu, Jun 14, 2012 at 03:01:27PM +0200, Peter Zijlstra wrote: > On Thu, 2012-06-14 at 05:59 -0700, Paul E. McKenney wrote: > > Yep, starvation. > > What's the particular starvation case? RCU callback processing consumes the entire CPU in RCU_BOOST case where processing runs at real-time priority. This is analogous to RT throttling in the scheduler. Thanx, Paul -- 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/