Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753199Ab0KKJRo (ORCPT ); Thu, 11 Nov 2010 04:17:44 -0500 Received: from mail-ey0-f174.google.com ([209.85.215.174]:46347 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751160Ab0KKJRi (ORCPT ); Thu, 11 Nov 2010 04:17:38 -0500 Date: Thu, 11 Nov 2010 09:17:34 +0000 From: Jamie Iles To: Ming Lei Cc: Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Russell King , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [Questions] How to run 'perf top' on ARM to profile kernel functions with modules loaded Message-ID: <20101111091733.GA2929@pulham.picochip.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 997 Lines: 23 On Thu, Nov 11, 2010 at 03:52:07PM +0800, Ming Lei wrote: > 2010/11/11 Ming Lei : > > Hi, > > > > 'perf top' can't display any functions when modules are loaded on ARM. > > Sorry, should be can't display any kernel functions when modules are loaded > on ARM. I've noticed this myself and I spent a bit of time looking into it last week but didn't get too far. I did wonder if it was something to do with the map fixups after loading the modules. If you look at the raw events after a perf record with 'perf report -D' then the last module has a size that takes it to 0xFFFFFFFF which overlaps with the rest of the kernel symbols. On x86 it looks like the modules are loaded after the kernel image in VM unlike ARM. Jamie -- 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/