Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752848AbbLKCnP (ORCPT ); Thu, 10 Dec 2015 21:43:15 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:44626 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbbLKCnO (ORCPT ); Thu, 10 Dec 2015 21:43:14 -0500 Message-ID: <566A3823.9080503@huawei.com> Date: Fri, 11 Dec 2015 10:42:43 +0800 From: "Wangnan (F)" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: =?UTF-8?B?5bmz5p2+6ZuF5bezIC8gSElSQU1BVFXvvIxNQVNBTUk=?= , "'Arnaldo Carvalho de Melo'" CC: Peter Zijlstra , Adrian Hunter , "linux-kernel@vger.kernel.org" , "linux-perf-users@vger.kernel.org" , Ingo Molnar , "Namhyung Kim" , Jiri Olsa , Alexei Starovoitov Subject: Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes References: <20151209021047.10245.8918.stgit@localhost.localdomain> <20151209134138.GB15864@kernel.org> <50399556C9727B4D88A595C8584AAB375264FB48@GSjpTKYDCembx32.service.hitachi.net> <56697572.90701@huawei.com> <20151210151239.GB17996@kernel.org> <50399556C9727B4D88A595C8584AAB37526515F5@GSjpTKYDCembx32.service.hitachi.net> In-Reply-To: <50399556C9727B4D88A595C8584AAB37526515F5@GSjpTKYDCembx32.service.hitachi.net> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.111.66.109] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.566A382E.0037,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: c4738d863c39b95709daee0a9a893f70 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4275 Lines: 126 On 2015/12/11 10:15, 平松雅巳 / HIRAMATU，MASAMI wrote: > From: 'Arnaldo Carvalho de Melo' [mailto:acme@kernel.org] >> But this requires having these special refcnt__ routines, that will make >> tools/perf/ code patterns for reference counts look different that the >> refcount patterns in the kernel :-\ > BTW, I think even without the refcnt debugger, we'd better introduce this > kind API to unify the refcnt operation in perf code. As I said, we have many > miscodings on current implementation. Unifying the API can enforce developers > to avoid such miscodings. > > Thank you, > I tried this problem in another way, I'd like to share it here. First: create two uprobes: # ./perf probe --exec /home/wangnan/perf dso__new%return %ax Added new event: probe_perf:dso__new (on dso__new%return in /home/wangnan/perf with %ax) You can now use it in all perf tools, such as: perf record -e probe_perf:dso__new -aR sleep 1 # ./perf probe --exec /home/wangnan/perf dso__delete dso Added new event: probe_perf:dso__delete (on dso__delete in /home/wangnan/perf with dso) You can now use it in all perf tools, such as: perf record -e probe_perf:dso__delete -aR sleep 1 Then start test: # ./perf record -g -e probe_perf:dso__new -e probe_perf:dso__delete ./perf probe vfs_read Added new event: probe:vfs_read (on vfs_read) You can now use it in all perf tools, such as: perf record -e probe:vfs_read -aR sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.048 MB perf.data (178 samples) ] From the perf report result I know two dso objects are leak: 90 probe_perf:dso__new ` 88 probe_perf:dso__delete Then convert output to CTF: $ ./perf data convert --to-ctf ./out.ctf With a python script, try to find the exact leak objects (I'm not good at python, I believe we can do this with much shorter script): $ cat refcnt.py from babeltrace import TraceCollection tc = TraceCollection(); tc.add_trace('./out.ctf', 'ctf') objs = {} for event in tc.events: if event.name.startswith('probe_perf:dso__new'): if event['arg1'] not in objs: objs[event['arg1']] = 1 if event.name.startswith('probe_perf:dso__delete'): if event['dso'] in objs: objs[event['dso']] = 0 for x in objs: if objs[x] is 0: continue print("0x%x" % x) $ python3 ./refcnt.py 0x34cb350 0x34d4640 Then from perf script's result, search for the two address: perf 23203 [004] 665244.170387: probe_perf:dso__new: (4aaee0 <- 50a5eb) arg1=0x34cb350 10a5eb dso__load_sym (/home/w00229757/perf) af42d dso__load_vmlinux (/home/w00229757/perf) af58c dso__load_vmlinux_path (/home/w00229757/perf) 10c40a open_debuginfo (/home/w00229757/perf) 111d39 convert_perf_probe_events (/home/w00229757/perf) 603a7 __cmd_probe.isra.3 (/home/w00229757/perf) 60a44 cmd_probe (/home/w00229757/perf) 7f6d1 run_builtin (/home/w00229757/perf) 33056 main (/home/w00229757/perf) 21bd5 __libc_start_main (/tmp/oxygen_root-w00229757/lib64/libc-2.18.so) perf 23203 [004] 665244.170679: probe_perf:dso__new: (4aaee0 <- 50a5eb) arg1=0x34d4640 10a5eb dso__load_sym (/home/w00229757/perf) af42d dso__load_vmlinux (/home/w00229757/perf) af58c dso__load_vmlinux_path (/home/w00229757/perf) 10c40a open_debuginfo (/home/w00229757/perf) 111d39 convert_perf_probe_events (/home/w00229757/perf) 603a7 __cmd_probe.isra.3 (/home/w00229757/perf) 60a44 cmd_probe (/home/w00229757/perf) 7f6d1 run_builtin (/home/w00229757/perf) 33056 main (/home/w00229757/perf) 21bd5 __libc_start_main (/tmp/oxygen_root-w00229757/lib64/libc-2.18.so) Thank you. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/