From patchwork Fri Sep 21 22:12:41 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 1493641 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 03CF4DF28C for ; Fri, 21 Sep 2012 22:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758282Ab2IUWMt (ORCPT ); Fri, 21 Sep 2012 18:12:49 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:43518 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757058Ab2IUWMs (ORCPT ); Fri, 21 Sep 2012 18:12:48 -0400 Received: from /spool/local by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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McKenney" To: Paul Walmsley Cc: "Bruce, Becky" , "Paul E. McKenney" , "" , "" , "" , "Hilman, Kevin" , "Shilimkar, Santosh" , "Hunter, Jon" , "" , fweisbec@gmail.com Subject: Re: rcu self-detected stall messages on OMAP3, 4 boards Message-ID: <20120921221241.GA7800@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20120920000351.GI2455@linux.vnet.ibm.com> <20120920220130.GN2449@linux.vnet.ibm.com> <20120920232114.GO2449@linux.vnet.ibm.com> <20120921185827.GC2454@linux.vnet.ibm.com> <20120921195717.GD2454@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120921195717.GD2454@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12092122-6148-0000-0000-000009E317EB Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On Fri, Sep 21, 2012 at 12:57:17PM -0700, Paul E. McKenney wrote: > On Fri, Sep 21, 2012 at 07:11:14PM +0000, Paul Walmsley wrote: > > On Fri, 21 Sep 2012, Paul E. McKenney wrote: [ . . . ] > > > I may take your advice of remote access to a Panda board, though that > > > is likely to take a bit of time due to timezones. Regardless of the > > > underlying issue here, I clearly need to make the stall-warning messages > > > do a better job of printing out needed information. > > > > If you've got a patch in mind for that, I'll boot it here. > > Hammering it out, will send it along when it is a bit less destructive. ;-) And I eventually decided to keep things simple, please see below. This applies on top of https://lkml.org/lkml/2012/8/30/290. Thanx, Paul ------------------------------------------------------------------------ rcu: Add grace-period information to RCU CPU stall warnings This commit causes the last grace period started and completed to be printed on RCU CPU stall warning messages in order to aid diagnosis. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/kernel/rcutree.c b/kernel/rcutree.c index cdaa7aa..fdb6854 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -925,8 +925,9 @@ static void print_other_cpu_stall(struct rcu_state *rsp) raw_spin_unlock_irqrestore(&rnp->lock, flags); print_cpu_stall_info_end(); - printk(KERN_CONT "(detected by %d, t=%ld jiffies)\n", - smp_processor_id(), (long)(jiffies - rsp->gp_start)); + pr_cont("(detected by %d, t=%ld jiffies, g=%lu, c=%lu)\n", + smp_processor_id(), (long)(jiffies - rsp->gp_start), + rsp->gpnum, rsp->completed); if (ndetected == 0) printk(KERN_ERR "INFO: Stall ended before state dump start\n"); else if (!trigger_all_cpu_backtrace()) @@ -953,7 +954,8 @@ static void print_cpu_stall(struct rcu_state *rsp) print_cpu_stall_info_begin(); print_cpu_stall_info(rsp, smp_processor_id()); print_cpu_stall_info_end(); - printk(KERN_CONT " (t=%lu jiffies)\n", jiffies - rsp->gp_start); + pr_cont(" (t=%lu jiffies g=%lu c=%lu)\n", + jiffies - rsp->gp_start, rsp->gpnum, rsp->completed); if (!trigger_all_cpu_backtrace()) dump_stack();