From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937640Ab0CPJzj (ORCPT ); Tue, 16 Mar 2010 05:55:39 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:54296 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937631Ab0CPJzh (ORCPT ); Tue, 16 Mar 2010 05:55:37 -0400 Date: Tue, 16 Mar 2010 10:55:23 +0100 From: Ingo Molnar To: David Miller Cc: acme@infradead.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, efault@gmx.de, a.p.zijlstra@chello.nl, paulus@samba.org Subject: Re: [PATCH 2/2] perf top: Properly notify the user that vmlinux is missing Message-ID: <20100316095523.GJ7961@elte.hu> References: <20100315192125.GL6965@ghostprotocols.net> <20100315.122605.124976085.davem@davemloft.net> <20100316094611.GG7961@elte.hu> <20100316.025134.196872789.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100316.025134.196872789.davem@davemloft.net> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * David Miller wrote: > From: Ingo Molnar > Date: Tue, 16 Mar 2010 10:46:11 +0100 > > > i'd really like that to happen - i.e. if we had the kernel (and modules) image > > exposed as a (almost-)standard ELF object via /sys or so. > > > > We already have some aspects of that, via /sys/kernel/notes, but it should be > > done for real. That would also make build-id support less of a hack. > > > > ( I'd not include CFI debuginfo in there though - that would be way too large. > > More compressed debuginfo could be included perhaps. ) > > That's interesting and useful, but wouldn't help my case as the images I'm > usually booting are completely stripped. /me too > That's why I end up with "[kernel.kallsyms]" for kernel profiling :-) The kernel image itself is still present in RAM, obviously. So are the symbols (packed for kallsyms). So exposing a virtual ELF image via /sys (or /proc/kernel.so) wouldnt take up much more RAM and would be rather useful, right? Ingo