Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933426AbaFRC1e (ORCPT ); Tue, 17 Jun 2014 22:27:34 -0400 Received: from mga03.intel.com ([143.182.124.21]:20016 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932442AbaFRC1d (ORCPT ); Tue, 17 Jun 2014 22:27:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,498,1400050800"; d="scan'208";a="446810162" Date: Tue, 17 Jun 2014 19:27:31 -0700 From: Andi Kleen To: "Paul E. McKenney" Cc: Dave Hansen , LKML , Josh Triplett , "Chen, Tim C" , Christoph Lameter , peterz@infradead.org Subject: Re: [bisected] pre-3.16 regression on open() scalability Message-ID: <20140618022731.GM8178@tassilo.jf.intel.com> References: <539B594C.8070004@intel.com> <20140613224519.GV4581@linux.vnet.ibm.com> <53A0CAE5.9000702@intel.com> <20140618001517.GL8178@tassilo.jf.intel.com> <20140618010423.GW4669@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140618010423.GW4669@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > OK. What would you suggest instead? If all we do is to revert the Hang checker should have two timer phases: Timer fires first time: - Save context switch counter on that. Force a reschedule to some work queue. Rearm timer Timer fires again: - Check reschedule count. If the reschedule count changed it was a real hang, otherwise ignore. -Andi -- 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/