Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757015Ab3GEGvS (ORCPT ); Fri, 5 Jul 2013 02:51:18 -0400 Received: from mail-ea0-f173.google.com ([209.85.215.173]:38210 "EHLO mail-ea0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716Ab3GEGvR (ORCPT ); Fri, 5 Jul 2013 02:51:17 -0400 Date: Fri, 5 Jul 2013 08:51:13 +0200 From: Ingo Molnar To: "H. Peter Anvin" , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker Cc: Linus Torvalds , Dave Jones , Linux Kernel , Thomas Gleixner Subject: Re: scheduling while atomic & hang. Message-ID: <20130705065113.GA6588@gmail.com> References: <20130704015525.GA8486@redhat.com> <51D5BA25.9060207@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51D5BA25.9060207@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1112 Lines: 30 * H. Peter Anvin wrote: > On 07/03/2013 07:49 PM, Linus Torvalds wrote: > >> [] __schedule+0x94f/0x9c0 > >> [] schedule_user+0x2e/0x70 > >> [] retint_careful+0x12/0x2e > > This call trace does indeed indicate that we took a hardware > interrupt which caused a reschedule. It doesn't necessarily have to > be a quantum expiration interrupt, it could just as easily be an I/O > completion interrupt. Too bad the kernel stack frame at this point is so small [we are just before return to userspace], so we don't really get our usual trace of recent activities via the '?' entries ... It would be nice to have a full-kernel-stack backtrace printout as an option, which prints entries 'above' the current RSP. I've Cc:-ed Frederic, maybe he has interest in implementing that? Thanks, Ingo -- 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/