From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755608Ab0LHPPb (ORCPT ); Wed, 8 Dec 2010 10:15:31 -0500 Received: from canuck.infradead.org ([134.117.69.58]:51239 "EHLO canuck.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753526Ab0LHPP3 convert rfc822-to-8bit (ORCPT ); Wed, 8 Dec 2010 10:15:29 -0500 Subject: Re: perf hw in kexeced kernel broken in tip From: Peter Zijlstra To: Vivek Goyal Cc: Don Zickus , "Eric W. Biederman" , Yinghai Lu , Ingo Molnar , Jason Wessel , "linux-kernel@vger.kernel.org" , Haren Myneni In-Reply-To: <20101208150243.GC31703@redhat.com> References: <1291234036.32004.2008.camel@laptop> <20101202052321.GH18100@redhat.com> <1291275270.4023.20.camel@twins> <20101202161502.GL18100@redhat.com> <1291764620.2032.1293.camel@laptop> <20101208140103.GM21786@redhat.com> <1291818005.28378.38.camel@laptop> <20101208144245.GB31703@redhat.com> <1291819684.28378.70.camel@laptop> <20101208150243.GC31703@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Wed, 08 Dec 2010 16:15:07 +0100 Message-ID: <1291821307.28378.93.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-12-08 at 10:02 -0500, Vivek Goyal wrote: > >but its kdump so its mostly broken by design anyway ;-) > > Kdump has its share of problems especially with the fact that > kernel/drivers find devices in bad state and are not hardened enough > to deal with that. But on bare metal what's the better way of capturing > kernel crash dump? Trying to do anything post crash in the kernel is > also not very reliable either. /me <3 RS-232 I haven't found anything better than that... And poking at the RS-232 requires less of the kernel to be functional than booting into a new kernel (whose image might have been corrupted by the dying kernel, etc..)