Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965974AbaFSVQj (ORCPT ); Thu, 19 Jun 2014 17:16:39 -0400 Received: from qmta07.emeryville.ca.mail.comcast.net ([76.96.30.64]:55152 "EHLO qmta07.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965515AbaFSVQh (ORCPT ); Thu, 19 Jun 2014 17:16:37 -0400 Date: Thu, 19 Jun 2014 16:16:34 -0500 (CDT) From: Christoph Lameter To: "Paul E. McKenney" cc: Andi Kleen , Dave Hansen , LKML , Josh Triplett , "Chen, Tim C" Subject: Re: [bisected] pre-3.16 regression on open() scalability In-Reply-To: Message-ID: References: <20140618001836.GV4669@linux.vnet.ibm.com> <53A132D4.60408@intel.com> <20140618125831.GB4669@linux.vnet.ibm.com> <53A1CE19.7040103@intel.com> <20140618203052.GT4669@linux.vnet.ibm.com> <20140618235131.GA25946@linux.vnet.ibm.com> <20140619014200.GO8178@tassilo.jf.intel.com> <20140619180916.GE4904@linux.vnet.ibm.com> <20140619204220.GJ4904@linux.vnet.ibm.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This looks very much like the CONFIG_PREEMPT problem in not so extreme form. Maybe we need to add another config option: CONFIG_REALLY_REALLY_NO_PREEMPT to get the fastest code possible and those cond_rescheds removed from the critical paths? Or better CONFIG_PREEMPT_HALF_WAY to enable those cond_rescheds. -- 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/