From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753713AbcDGIT2 (ORCPT ); Thu, 7 Apr 2016 04:19:28 -0400 Received: from mail-pa0-f66.google.com ([209.85.220.66]:35581 "EHLO mail-pa0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750784AbcDGITZ (ORCPT ); Thu, 7 Apr 2016 04:19:25 -0400 Subject: Re: [PATCH 0/2] perf probe fixes for ppc64le To: "Naveen N. Rao" , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: Cc: Mark Wielaard , Arnaldo Carvalho de Melo , Masami Hiramatsu , Thiago Jung Bauermann From: Balbir Singh Message-ID: <57061802.7020508@gmail.com> Date: Thu, 7 Apr 2016 18:19:14 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/04/16 22:32, Naveen N. Rao wrote: > This patchset fixes three issues found with perf probe on ppc64le: > 1. 'perf test kallsyms' failure on ppc64le (reported by Michael > Ellerman). This was due to the symbols being fixed up during symbol > table load. This is fixed in patch 2 by delaying symbol fixup until > later. > 2. perf probe function offset was being calculated from the local entry > point (LEP), which does not match user expectation when trying to look > at function disassembly output (reported by Ananth N). This is fixed for > kallsyms in patch 1 and for symbol table in patch 2. I think the bit where the offset is w.r.t LEP when using a name, but w.r.t GEP when using function+offset can be confusing. Do we really need probe points between GEP and LEP? All the GEP does is setup r2. The use case could be more generic, but please clarify. > 3. perf probe failure with kretprobe when using kallsyms. This was > failing as we were specifying an offset. This is fixed in patch 1. > Balbir Singh.