From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752825AbbHERBZ (ORCPT ); Wed, 5 Aug 2015 13:01:25 -0400 Received: from casper.infradead.org ([85.118.1.10]:38008 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259AbbHERBY (ORCPT ); Wed, 5 Aug 2015 13:01:24 -0400 Date: Wed, 5 Aug 2015 19:01:00 +0200 From: Peter Zijlstra To: Alexander Shishkin Cc: Ingo Molnar , linux-kernel@vger.kernel.org, adrian.hunter@intel.com, Arnaldo Carvalho de Melo , Vince Weaver , Stephane Eranian Subject: Re: [PATCH RFC v1 0/4] perf: Introduce extended syscall error reporting Message-ID: <20150805170100.GP19282@twins.programming.kicks-ass.net> References: <1437738359-23920-1-git-send-email-alexander.shishkin@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1437738359-23920-1-git-send-email-alexander.shishkin@linux.intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 24, 2015 at 02:45:55PM +0300, Alexander Shishkin wrote: > Hi Peter and Ingo and everybody, > > Here's my second stab at improving perf's error reporting by attaching > arbitrary strings to the integer error codes. This is largely based > off of the previous email thread [1]. > > This time around, I employed a linker trick to convert the structures > containing extended error information into integers, which are then > made to look just like normal error codes so that IS_ERR_VALUE() and > friends would still work correctly on them. So no extra pointers in > the struct perf_event or anywhere else; the extended error codes are > passed around like normal error codes. They only need to be converted > in syscalls' topmost return statements. This is done in 1/4. > > Then, 2/4 illustrates how error sites can be extended to include more > information such as file names and line numbers [1]. > > The other two patches add perf_err() annotation to a few semi-randomly > picked places in perf core (3/4) and x86 bits (4/4). Looks generally ok to me. Thanks for doing this.