Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762231AbYAKTmU (ORCPT ); Fri, 11 Jan 2008 14:42:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758232AbYAKTmN (ORCPT ); Fri, 11 Jan 2008 14:42:13 -0500 Received: from smtp2.linux-foundation.org ([207.189.120.14]:46953 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759541AbYAKTmM (ORCPT ); Fri, 11 Jan 2008 14:42:12 -0500 Date: Fri, 11 Jan 2008 11:41:40 -0800 (PST) From: Linus Torvalds To: Arjan van de Ven cc: linux-kernel@vger.kernel.org, mingo@elte.hu, akpm@linux-foundation.org Subject: Re: Make the 32 bit Frame Pointer backtracer fall back to traditional In-Reply-To: <20080110203519.573567b7@laptopd505.fenrus.org> Message-ID: References: <20080109220508.686bbda4@laptopd505.fenrus.org> <20080110203519.573567b7@laptopd505.fenrus.org> User-Agent: Alpine 1.00 (LFD 882 2007-12-20) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1404 Lines: 34 On Thu, 10 Jan 2008, Arjan van de Ven wrote: > > What do you think of this approach instead of your proposal? Looks ok to me. I get the feeling that we *should* be able to make the #ifdef CONFIG_FRAME_POINTER .. thing be a bit cleaner with this (since you have the non-frame-pointer thing inside the loop as well), and use one common routine for it all, with just certain helper functions always retuning a NULL or something for the non-frame-pointer thing. In other words, I *think* the non-frame-pointer case should always be doable as a "series of single-word unverified frames", but if that kind of cleanup doesn't work, I certainly don't hate your patch either.. (I also wonder if we should limit the number of entries we print out. Sometimes the stack frame ends up being so deep that we lose the *important* stuff. I think it might be good idea to have some rule like "the first 5 entries go to the screen, the rest will be KERN_DEBUG and only go to the logs by default" - so a "dmesg" would show it all, but if the machine is hung, the screen won't have been scrolled away from all the other things by a long backtrace!) Linus -- 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/