From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754746AbcCWLBJ (ORCPT ); Wed, 23 Mar 2016 07:01:09 -0400 Received: from casper.infradead.org ([85.118.1.10]:48211 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751925AbcCWLA5 (ORCPT ); Wed, 23 Mar 2016 07:00:57 -0400 Date: Wed, 23 Mar 2016 11:41:29 +0100 From: Peter Zijlstra To: Jiri Olsa Cc: Steven Rostedt , lkml , Ingo Molnar , Namhyung Kim , Arnaldo Carvalho de Melo Subject: Re: [PATCH 2/5] ftrace perf: Move exclude_kernel tracepoint check to init event Message-ID: <20160323104129.GZ6344@twins.programming.kicks-ass.net> References: <1458138873-1553-1-git-send-email-jolsa@kernel.org> <1458138873-1553-3-git-send-email-jolsa@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1458138873-1553-3-git-send-email-jolsa@kernel.org> 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 Wed, Mar 16, 2016 at 03:34:30PM +0100, Jiri Olsa wrote: > We suppress events with attr::exclude_kernel set when > the event is generated, so following capture will > give no warning but won't produce any data: > > $ sudo perf record -e sched:sched_switch:u ls > $ sudo /perf script | wc -l > 0 > > Checking the attr::exclude_(kernel|user) at the event > init time and failing right away for tracepoints from > uprobes/kprobes and native ones: > > $ sudo perf record -e sched:sched_switch:u ls > Error: > The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (sched:sched_switch). > /bin/dmesg may provide additional information. > No CONFIG_PERF_EVENTS=y kernel support configured? > > $ sudo perf record -e probe:sys_read:u ls > Error: > The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (probe:sys_read). > /bin/dmesg may provide additional information. > No CONFIG_PERF_EVENTS=y kernel support configured? > > $ ./perf record -e probe_ex:main:k ./ex > Error: > The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (probe_ex:main). > /bin/dmesg may provide additional information. > No CONFIG_PERF_EVENTS=y kernel support configured? Not sure about this one. The previous behaviour suggests exclude_{user,kernel} is implemented, while the new behaviour says these flags are not implemented, which is a functional regression. That is, if all events are from kernel space, and we exclude all kernel events, 0 is the right answer not an error. Sure, with uprobes the situation is currently broken, but this isn't a fix.