From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752173AbeEPSEh (ORCPT ); Wed, 16 May 2018 14:04:37 -0400 Received: from terminus.zytor.com ([198.137.202.136]:54509 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751457AbeEPSEg (ORCPT ); Wed, 16 May 2018 14:04:36 -0400 Date: Wed, 16 May 2018 11:04:26 -0700 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: adrian.hunter@intel.com, wangnan0@huawei.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, dsahern@gmail.com, tglx@linutronix.de, acme@redhat.com, jolsa@kernel.org, mingo@kernel.org Reply-To: mingo@kernel.org, acme@redhat.com, jolsa@kernel.org, hpa@zytor.com, tglx@linutronix.de, dsahern@gmail.com, adrian.hunter@intel.com, linux-kernel@vger.kernel.org, namhyung@kernel.org, wangnan0@huawei.com To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf bpf: Add probe() helper to reduce kprobes boilerplate Git-Commit-ID: d8fc764d0b39c912de510b50102b60a64882223e 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: d8fc764d0b39c912de510b50102b60a64882223e Gitweb: https://git.kernel.org/tip/d8fc764d0b39c912de510b50102b60a64882223e Author: Arnaldo Carvalho de Melo AuthorDate: Fri, 4 May 2018 15:59:16 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 15 May 2018 14:31:24 -0300 perf bpf: Add probe() helper to reduce kprobes boilerplate So that kprobe definitions become: int probe(function, variables)(void *ctx, int err, var1, var2, ...) The existing 5sec.c, got converted and goes from: SEC("func=hrtimer_nanosleep rqtp->tv_sec") int func(void *ctx, int err, long sec) { } To: int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec) { } If we decide to add tv_nsec as well, then it becomes: $ cat tools/perf/examples/bpf/5sec.c #include int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec) { return sec == 5; } license(GPL); $ And if we run it, system wide as before and run some 'sleep' with values for the tv_nsec field, we get: # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c 0.000 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=100000000 9641.650 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=123450001 ^C# Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-1v9r8f6ds5av0w9pcwpeknyl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/examples/bpf/5sec.c | 10 ++++++++-- tools/perf/include/bpf/bpf.h | 3 +++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/tools/perf/examples/bpf/5sec.c b/tools/perf/examples/bpf/5sec.c index 6fc3697ac749..b9c203219691 100644 --- a/tools/perf/examples/bpf/5sec.c +++ b/tools/perf/examples/bpf/5sec.c @@ -15,6 +15,13 @@ . While this is running, run something like "sleep 5s". + . If we decide to add tv_nsec as well, then it becomes: + + int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec) + + I.e. add where it comes from (rqtp->tv_nsec) and where it will be + accessible in the function body (nsec) + # 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]) @@ -34,8 +41,7 @@ #include -SEC("func=hrtimer_nanosleep rqtp->tv_sec") -int func(void *ctx, int err, long sec) +int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec) { return sec == 5; } diff --git a/tools/perf/include/bpf/bpf.h b/tools/perf/include/bpf/bpf.h index cdfd18b9c318..dd764ad5efdf 100644 --- a/tools/perf/include/bpf/bpf.h +++ b/tools/perf/include/bpf/bpf.h @@ -3,6 +3,9 @@ #define _PERF_BPF_H #define SEC(NAME) __attribute__((section(NAME), used)) +#define probe(function, vars) \ + SEC(#function "=" #function " " #vars) function + #define license(name) \ char _license[] SEC("license") = #name; \ int _version SEC("version") = LINUX_VERSION_CODE;