From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751992Ab3LJWRd (ORCPT <rfc822;w@1wt.eu>);
	Tue, 10 Dec 2013 17:17:33 -0500
Received: from mx1.redhat.com ([209.132.183.28]:62347 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751779Ab3LJWRa (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Tue, 10 Dec 2013 17:17:30 -0500
Date: Tue, 10 Dec 2013 17:16:21 -0500
From: Dave Jones <davej@redhat.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Darren Hart <dvhart@linux.intel.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Mel Gorman <mgorman@suse.de>
Subject: Re: process 'stuck' at exit.
Message-ID: <20131210221621.GD5050@redhat.com>
Mail-Followup-To: Dave Jones <davej@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Oleg Nesterov <oleg@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Darren Hart <dvhart@linux.intel.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>, Mel Gorman <mgorman@suse.de>
References: <20131210154724.GA30020@redhat.com>
 <CA+55aFxgFAfcQKDoDhmJcCRb5pfxumxJ9OmpUhhNzs+CY_Yqqw@mail.gmail.com>
 <alpine.DEB.2.02.1312102001090.28330@ionos.tec.linutronix.de>
 <CA+55aFzLnheC6W+Db=-MVr6aR5UzP-c1Q1yk_aN-9gxSjUpANw@mail.gmail.com>
 <20131210203559.GA1209@redhat.com>
 <20131210204925.GB27373@redhat.com>
 <20131210213431.GA6342@redhat.com>
 <20131210214143.GG27373@redhat.com>
 <20131210220946.GA6962@home.goodmis.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20131210220946.GA6962@home.goodmis.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Dec 10, 2013 at 05:09:46PM -0500, Steven Rostedt wrote:
 
 > So you can do either:
 > 
 > trace-cmd record -p function -l get_user_pages_fast --func-stack sleep 5
 > 
 > Which will trace the get_user_pages_fast and spit out a full call trace.
This gives me a 100M trace.dat, but trace show shows..

# tracer: nop
#
# entries-in-buffer/entries-written: 0/0   #P:4
#
#                              _-----=> irqs-off
#                             / _----=> need-resched
#                            | / _---=> hardirq/softirq
#                            || / _--=> preempt-depth
#                            ||| /     delay
#           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
#              | |       |   ||||       |         |

and that's it.
 
 > Or if you don't want to use trace-cmd, you can do it by hand.

Given the state the system is in, I don't want to perturb it too much.

	Dave