From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933141AbcHCXIN (ORCPT ); Wed, 3 Aug 2016 19:08:13 -0400 Received: from mail.kernel.org ([198.145.29.136]:37550 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932913AbcHCXIK (ORCPT ); Wed, 3 Aug 2016 19:08:10 -0400 Date: Thu, 4 Aug 2016 08:08:00 +0900 From: Masami Hiramatsu To: Masami Hiramatsu Cc: "Wangnan (F)" , Arnaldo Carvalho de Melo , Linux Kernel Mailing List Subject: Re: perf test BPF failing on f24: fix Message-Id: <20160804080800.a056b02044c1e749bac02cbe@kernel.org> In-Reply-To: <20160803234557.29f43f755b7e14c634a54a9a@kernel.org> References: <20160802195102.GD14639@kernel.org> <57A1A913.6000307@huawei.com> <20160803234557.29f43f755b7e14c634a54a9a@kernel.org> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Aug 2016 23:45:57 +0900 Masami Hiramatsu wrote: > > > [root@jouet ~]# perf probe sys_epoll_wait > > > Failed to find debug information for address ffffffffbd295b50 > > > Probe point 'sys_epoll_wait' not found. > > > Error: Failed to add events. > > So, at least I should investigate it. FYI, on ubuntu16.04, I can put probes on sys_epoll_wait as below mhiramat@devnote:~/ksrc/linux/tools/perf$ sudo ./perf probe -vnf sys_epoll_wait probe-definition(0): sys_epoll_wait symbol:sys_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux-4.4.0-31-generic for symbols Open Debuginfo file: /usr/lib/debug/boot/vmlinux-4.4.0-31-generic Try to find probe point from debuginfo. Symbol sys_epoll_wait address found : ffffffff81257410 Matched function: SyS_epoll_wait found inline addr: 0xffffffff81257410 Probe point found: SyS_epoll_wait+0 found inline addr: 0xffffffff8125756d Probe point found: SyS_epoll_pwait+141 found inline addr: 0xffffffff81257793 Probe point found: compat_SyS_epoll_pwait+147 Found 3 probe_trace_events. Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: p:probe/sys_epoll_wait _text+2454544 Writing event: p:probe/sys_epoll_wait_1 _text+2454893 Writing event: p:probe/sys_epoll_wait_2 _text+2455443 Added new events: probe:sys_epoll_wait (on sys_epoll_wait) probe:sys_epoll_wait_1 (on sys_epoll_wait) probe:sys_epoll_wait_2 (on sys_epoll_wait) You can now use it in all perf tools, such as: perf record -e probe:sys_epoll_wait_2 -aR sleep 1 -- Masami Hiramatsu