From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable Date: Tue, 20 Mar 2007 11:49:39 -0700 (PDT) Message-ID: References: <20070319.120854.30182994.davem@davemloft.net> <20070319.204712.118947830.davem@davemloft.net> <200703201428.50564.ak@suse.de> <20070320174159.GA4286@bingen.suse.de> <20070320180359.GB4286@bingen.suse.de> <20070320192118.GD4286@bingen.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20070320192118.GD4286@bingen.suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Andi Kleen Cc: xen-devel@lists.xensource.com, netdev@vger.kernel.org, mingo@elte.hu, linux-kernel@vger.kernel.org, jbeulich@novell.com, virtualization@lists.linux-foundation.org, chrisw@sous-sol.org, virtualization@lists.osdl.org, "Eric W. Biederman" , anthony@codemonkey.ws, akpm@linux-foundation.org, David Miller List-Id: virtualization@lists.linuxfoundation.org On Tue, 20 Mar 2007, Andi Kleen wrote: > = > So what is your proposed alternative to handle long backtraces? = > You didn't answer that question. Please do, I'm curious about your though= ts > in this area. the thing is, I'd rather see a long backtrace that is hard to decipher but = that *never* *ever* causes any additional problems, over a pretty one. Because that's really the issue: do you want a "pretty" backtrace, or do = you want one that is rock solid but has some crud in it. I'll take the rock solid one any day. Especially as even the pretty one = won't fix the most common problem, which is "I don't see the caller" (due = to inlining or tail-calls). In contrast, the ugly backtrace will have some "garbage entries" from = previous frames that didn't get overwritten, but there have actually been = (admittedly rare) cases where those garbage entries have given hints about = what happened just before. Linus