From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wzl7V3Z5ZzDr8P for ; Sat, 1 Jul 2017 04:15:17 +1000 (AEST) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v5UIE6Bc016962 for ; Fri, 30 Jun 2017 14:15:14 -0400 Received: from e18.ny.us.ibm.com (e18.ny.us.ibm.com [129.33.205.208]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bdqvshcwy-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 30 Jun 2017 14:15:14 -0400 Received: from localhost by e18.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 30 Jun 2017 14:15:13 -0400 Date: Fri, 30 Jun 2017 11:15:11 -0700 From: "Paul E. McKenney" To: Nicholas Piggin Cc: Abdul Haleem , sachinp , Stephen Rothwell , Paul McKenney , linux-kernel , linux-next , paulus@samba.org, linuxppc-dev Subject: Re: [linux-next] cpus stalls detected few hours after booting next kernel Reply-To: paulmck@linux.vnet.ibm.com References: <1498728106.19484.21.camel@abdul> <20170629193614.376e27e6@roar.ozlabs.ibm.com> <20170629202305.6187367f@roar.ozlabs.ibm.com> <20170630004534.228f7c08@roar.ozlabs.ibm.com> <1498800138.19484.25.camel@abdul> <20170630172802.6d4ddca2@roar.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170630172802.6d4ddca2@roar.ozlabs.ibm.com> Message-Id: <20170630181511.GC2393@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Jun 30, 2017 at 05:28:02PM +1000, Nicholas Piggin wrote: > On Fri, 30 Jun 2017 10:52:18 +0530 > Abdul Haleem wrote: > > > On Fri, 2017-06-30 at 00:45 +1000, Nicholas Piggin wrote: > > > On Thu, 29 Jun 2017 20:23:05 +1000 > > > Nicholas Piggin wrote: > > > > > > > On Thu, 29 Jun 2017 19:36:14 +1000 > > > > Nicholas Piggin wrote: > > > > > > > > I don't *think* the replay-wakeup-interrupt patch is directly involved, but > > > > > it's likely to be one of the idle patches. > > > > > > Okay this turned out to be misconfigured sleep states I added for the > > > simulator, sorry for the false alarm. > > > > > > > Although you have this in the backtrace. I wonder if that's a stuck > > > > lock in rcu_process_callbacks? > > > > > > So this spinlock becomes top of the list of suspects. Can you try > > > enabling lockdep and try to reproduce it? > > > > Yes, recreated again with CONFIG_LOCKDEP=y & CONFIG_DEBUG_LOCKDEP=y set. > > I do not see any difference in trace messages with and without LOCKDEP > > enabled. > > > > Please find the attached log file. > > Can you get an rcu_invoke_callback event trace that Paul suggested? > > Does this bug show up with just the powerpc next branch? And I must say that those RCU CPU stall warnings are spectacular! Did you by chance boot with a small subset of the CPUs online, and bring the rest online later on? Thanx, Paul