From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755718AbcHDBus (ORCPT ); Wed, 3 Aug 2016 21:50:48 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:6402 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753753AbcHDBum (ORCPT ); Wed, 3 Aug 2016 21:50:42 -0400 Subject: Re: perf test BPF failing on f24: fix To: Masami Hiramatsu References: <20160802195102.GD14639@kernel.org> <57A1A913.6000307@huawei.com> <20160803234557.29f43f755b7e14c634a54a9a@kernel.org> <20160804080800.a056b02044c1e749bac02cbe@kernel.org> CC: Arnaldo Carvalho de Melo , Linux Kernel Mailing List From: "Wangnan (F)" Message-ID: <57A29F61.5050702@huawei.com> Date: Thu, 4 Aug 2016 09:50:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <20160804080800.a056b02044c1e749bac02cbe@kernel.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.66.109] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.57A29F69.004D,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: e556c4af2923651ce1ce6a9ca79992a0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/8/4 7:08, Masami Hiramatsu wrote: > 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 > Have you checked 'readelf -wi'? I guess you wouldn't find sys_epoll_wait. Thank you.