From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751985AbeEPSDl (ORCPT ); Wed, 16 May 2018 14:03:41 -0400 Received: from terminus.zytor.com ([198.137.202.136]:45553 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750799AbeEPSDj (ORCPT ); Wed, 16 May 2018 14:03:39 -0400 Date: Wed, 16 May 2018 11:03:29 -0700 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: tglx@linutronix.de, dsahern@gmail.com, wangnan0@huawei.com, acme@redhat.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, jolsa@kernel.org, mingo@kernel.org, hpa@zytor.com, adrian.hunter@intel.com Reply-To: wangnan0@huawei.com, dsahern@gmail.com, tglx@linutronix.de, namhyung@kernel.org, acme@redhat.com, jolsa@kernel.org, linux-kernel@vger.kernel.org, adrian.hunter@intel.com, hpa@zytor.com, mingo@kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf bpf: Add kprobe example to catch 5s naps Git-Commit-ID: 7542b767b0469f4a76afa3feae6246d8a3d44e7f X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7542b767b0469f4a76afa3feae6246d8a3d44e7f Gitweb: https://git.kernel.org/tip/7542b767b0469f4a76afa3feae6246d8a3d44e7f Author: Arnaldo Carvalho de Melo AuthorDate: Fri, 4 May 2018 15:08:01 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 15 May 2018 14:31:24 -0300 perf bpf: Add kprobe example to catch 5s naps Description: . Disable strace like syscall tracing (--no-syscalls), or try tracing just some (-e *sleep). . Attach a filter function to a kernel function, returning when it should be considered, i.e. appear on the output: $ cat tools/perf/examples/bpf/5sec.c #include SEC("func=hrtimer_nanosleep rqtp->tv_sec") int func(void *ctx, int err, long sec) { return sec == 5; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; $ . Run it system wide, so that any sleep of >= 5 seconds and < than 6 seconds gets caught. . Ask for callgraphs using DWARF info, so that userspace can be unwound . While this is running, run something like "sleep 5s". # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/ 0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5 hrtimer_nanosleep ([kernel.kallsyms]) __x64_sys_nanosleep ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64 ([kernel.kallsyms]) __GI___nanosleep (/usr/lib64/libc-2.26.so) rpl_nanosleep (/usr/bin/sleep) xnanosleep (/usr/bin/sleep) main (/usr/bin/sleep) __libc_start_main (/usr/lib64/libc-2.26.so) _start (/usr/bin/sleep) ^C# Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-2nmxth2l2h09f9gy85lyexcq@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/examples/bpf/5sec.c | 44 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/tools/perf/examples/bpf/5sec.c b/tools/perf/examples/bpf/5sec.c new file mode 100644 index 000000000000..3d1ed34aec8b --- /dev/null +++ b/tools/perf/examples/bpf/5sec.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + Description: + + . Disable strace like syscall tracing (--no-syscalls), or try tracing + just some (-e *sleep). + + . Attach a filter function to a kernel function, returning when it should + be considered, i.e. appear on the output. + + . Run it system wide, so that any sleep of >= 5 seconds and < than 6 + seconds gets caught. + + . Ask for callgraphs using DWARF info, so that userspace can be unwound + + . While this is running, run something like "sleep 5s". + + # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/ + 0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5 + hrtimer_nanosleep ([kernel.kallsyms]) + __x64_sys_nanosleep ([kernel.kallsyms]) + do_syscall_64 ([kernel.kallsyms]) + entry_SYSCALL_64 ([kernel.kallsyms]) + __GI___nanosleep (/usr/lib64/libc-2.26.so) + rpl_nanosleep (/usr/bin/sleep) + xnanosleep (/usr/bin/sleep) + main (/usr/bin/sleep) + __libc_start_main (/usr/lib64/libc-2.26.so) + _start (/usr/bin/sleep) + ^C# + + Copyright (C) 2018 Red Hat, Inc., Arnaldo Carvalho de Melo +*/ + +#include + +SEC("func=hrtimer_nanosleep rqtp->tv_sec") +int func(void *ctx, int err, long sec) +{ + return sec == 5; +} + +char _license[] SEC("license") = "GPL"; +int _version SEC("version") = LINUX_VERSION_CODE;