From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758380Ab3JOFcv (ORCPT ); Tue, 15 Oct 2013 01:32:51 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33687 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932813Ab3JOFcr (ORCPT ); Tue, 15 Oct 2013 01:32:47 -0400 Date: Mon, 14 Oct 2013 22:32:35 -0700 From: tip-bot for Ramkumar Ramachandra Message-ID: Cc: acme@redhat.com, linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, dsahern@gmail.com, artagnon@gmail.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, acme@redhat.com, dsahern@gmail.com, tglx@linutronix.de, artagnon@gmail.com In-Reply-To: <1380863851-14460-1-git-send-email-artagnon@gmail.com> References: <1380863851-14460-1-git-send-email-artagnon@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf trace: Improve the error messages Git-Commit-ID: 87f918685a452be514d060a09eeb4e0c91422e86 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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.1 (terminus.zytor.com [127.0.0.1]); Mon, 14 Oct 2013 22:32:41 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 87f918685a452be514d060a09eeb4e0c91422e86 Gitweb: http://git.kernel.org/tip/87f918685a452be514d060a09eeb4e0c91422e86 Author: Ramkumar Ramachandra AuthorDate: Fri, 4 Oct 2013 10:47:31 +0530 Committer: Arnaldo Carvalho de Melo CommitDate: Mon, 14 Oct 2013 10:24:04 -0300 perf trace: Improve the error messages Currently, execution of 'perf trace' reports the following cryptic message to the user: $ perf trace Couldn't read the raw_syscalls tracepoints information! Typically this happens because the user does not have permissions to read the debugfs filesystem. Also handle the case when the kernel was not compiled with debugfs support or when it isn't mounted. Now, the tool prints detailed error messages: $ perf trace Error: Unable to find debugfs Hint: Was your kernel was compiled with debugfs support? Hint: Is the debugfs filesystem mounted? Hint: Try 'sudo mount -t debugfs nodev /sys/kernel/debug' $ perf trace Error: No permissions to read /sys/kernel/debug//tracing/events/raw_syscalls Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/' Signed-off-by: Ramkumar Ramachandra Cc: David Ahern Cc: Ingo Molnar Link: http://lkml.kernel.org/r/1380863851-14460-1-git-send-email-artagnon@gmail.com [ Added ready to use commands to fix the issues as extra hints, use the current debugfs mount point when reporting permission error, use strerror_r instead of the deprecated sys_errlist, as reported by David Ahern ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 19ddcab..5496546 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1590,17 +1590,13 @@ static int trace__run(struct trace *trace, int argc, const char **argv) } if (perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_enter", trace__sys_enter) || - perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit", trace__sys_exit)) { - fprintf(trace->output, "Couldn't read the raw_syscalls tracepoints information!\n"); - goto out_delete_evlist; - } + perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit", trace__sys_exit)) + goto out_error_tp; if (trace->sched && - perf_evlist__add_newtp(evlist, "sched", "sched_stat_runtime", - trace__sched_stat_runtime)) { - fprintf(trace->output, "Couldn't read the sched_stat_runtime tracepoint information!\n"); - goto out_delete_evlist; - } + perf_evlist__add_newtp(evlist, "sched", "sched_stat_runtime", + trace__sched_stat_runtime)) + goto out_error_tp; err = perf_evlist__create_maps(evlist, &trace->opts.target); if (err < 0) { @@ -1717,6 +1713,29 @@ out_delete_evlist: out: trace->live = false; return err; +out_error_tp: + switch(errno) { + case ENOENT: + fputs("Error:\tUnable to find debugfs\n" + "Hint:\tWas your kernel was compiled with debugfs support?\n" + "Hint:\tIs the debugfs filesystem mounted?\n" + "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'\n", + trace->output); + break; + case EACCES: + fprintf(trace->output, + "Error:\tNo permissions to read %s/tracing/events/raw_syscalls\n" + "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n", + debugfs_mountpoint, debugfs_mountpoint); + break; + default: { + char bf[256]; + fprintf(trace->output, "Can't trace: %s\n", + strerror_r(errno, bf, sizeof(bf))); + } + break; + } + goto out_delete_evlist; } static int trace__replay(struct trace *trace)