From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933316AbcBYQtG (ORCPT ); Thu, 25 Feb 2016 11:49:06 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:45561 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933246AbcBYQtD (ORCPT ); Thu, 25 Feb 2016 11:49:03 -0500 Date: Thu, 25 Feb 2016 17:48:47 +0100 From: Peter Zijlstra To: Alexei Starovoitov Cc: "David S. Miller" , Ingo Molnar , Steven Rostedt , Wang Nan , Daniel Borkmann , Brendan Gregg , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next 1/3] perf: generalize perf_callchain Message-ID: <20160225164847.GT6356@twins.programming.kicks-ass.net> References: <1455767939-2700534-1-git-send-email-ast@fb.com> <1455767939-2700534-2-git-send-email-ast@fb.com> <20160225141859.GM6357@twins.programming.kicks-ass.net> <56CF2DCE.5010501@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56CF2DCE.5010501@fb.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 Thu, Feb 25, 2016 at 08:37:34AM -0800, Alexei Starovoitov wrote: > On 2/25/16 6:18 AM, Peter Zijlstra wrote: > >> arch/x86/include/asm/stacktrace.h | 2 +- > >> arch/x86/kernel/cpu/perf_event.c | 4 ++-- > >> arch/x86/kernel/dumpstack.c | 6 ++++-- > >> arch/x86/kernel/stacktrace.c | 18 +++++++++++------- > >> arch/x86/oprofile/backtrace.c | 3 ++- > >> include/linux/perf_event.h | 13 +++++++++++-- > >> kernel/events/callchain.c | 32 ++++++++++++++++++++------------ > >> kernel/events/internal.h | 2 -- > >> 8 files changed, 51 insertions(+), 29 deletions(-) > > > >And at the very least this should have had a note that it doesn't break > >all the other archs that implement perf-callchain stuff. > > the cross-arch interface is two weak functions > perf_callchain_kernel() and perf_callchain_user() > and back into generic via perf_callchain_store(). > Nothing changes there. The code speaks for itself. > "non-x86 archs are not broken" would be a silly comment. No, a diffstat like that immediately makes me wonder if you've even bothered looking at !x86. A statement to this effect would've shown you did indeed consider it.