Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757663AbbKFXuZ (ORCPT ); Fri, 6 Nov 2015 18:50:25 -0500 Received: from mga11.intel.com ([192.55.52.93]:29560 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753334AbbKFXuY (ORCPT ); Fri, 6 Nov 2015 18:50:24 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,254,1444719600"; d="scan'208";a="680091452" Date: Fri, 6 Nov 2015 15:49:29 -0800 From: Jacob Pan To: Peter Zijlstra Cc: Thomas Gleixner , LKML , Arjan van de Ven , Paul Turner , Len Brown , Srinivas Pandruvada , Tim Chen , Andi Kleen , Rafael Wysocki , jacob.jun.pan@linux.intel.com Subject: Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection Message-ID: <20151106154929.39aa6701@icelake> In-Reply-To: <20151106074510.GM3604@twins.programming.kicks-ass.net> References: <1446509428-5616-1-git-send-email-jacob.jun.pan@linux.intel.com> <1446509428-5616-4-git-send-email-jacob.jun.pan@linux.intel.com> <20151103133120.GD17308@twins.programming.kicks-ass.net> <20151105135952.GE11639@twins.programming.kicks-ass.net> <20151105153625.25fbfe69@icelake> <20151106074510.GM3604@twins.programming.kicks-ass.net> Organization: OTC X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1152 Lines: 25 On Fri, 6 Nov 2015 08:45:10 +0100 Peter Zijlstra wrote: > On Thu, Nov 05, 2015 at 03:36:25PM -0800, Jacob Pan wrote: > > > I did some testing with the code below, it shows random > > [ 150.442597] NOHZ: local_softirq_pending 02 > > [ 153.032673] NOHZ: local_softirq_pending 202 > > [ 153.203785] NOHZ: local_softirq_pending 202 > > [ 153.206486] NOHZ: local_softirq_pending 282 > > I recalled that was why i checked for local_softirq_pending in the > > initial patch, still trying to find out how we can avoid that. These > > also causes non stop sched ticks in the inner idle loop. > > Check the softirq stuff before calling throttle ? yes, played with it but it seems there are other cases causing pending softirq in idle in addition to throttle. I still haven't figure it out, this problem only shows up in heavy irq, network load. e.g. compile kernel over NFS. Debugging. -- 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/