LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Clark Williams <williams@redhat.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Andi Kleen <ak@linux.intel.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [PATCH 12/17] perf record: Remove misleading error suggestion
Date: Fri, 20 Apr 2018 11:32:22 -0300	[thread overview]
Message-ID: <20180420143227.16030-13-acme@kernel.org> (raw)
In-Reply-To: <20180420143227.16030-1-acme@kernel.org>

From: Andi Kleen <ak@linux.intel.com>

When perf record encounters an error setting up an event it suggests
to enable CONFIG_PERF_EVENTS. This is misleading because:

- Usually it is enabled (it is really hard to disable on x86)

- The problem is usually somewhere else, e.g. the CPU is not supported
or an invalid configuration has been used.

Remove the misleading suggestion.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20180406203812.3087-4-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/evsel.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 1ac8d9236efd..66b62570c855 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2894,8 +2894,7 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 
 	return scnprintf(msg, size,
 	"The sys_perf_event_open() syscall returned with %d (%s) for event (%s).\n"
-	"/bin/dmesg may provide additional information.\n"
-	"No CONFIG_PERF_EVENTS=y kernel support configured?",
+	"/bin/dmesg | grep -i perf may provide additional information.\n",
 			 err, str_error_r(err, sbuf, sizeof(sbuf)),
 			 perf_evsel__name(evsel));
 }
-- 
2.14.3

  parent reply	other threads:[~2018-04-20 14:35 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-20 14:32 [GIT PULL 00/17] perf/urgent fixes and improvements Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 02/17] perf/core: Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE] Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 03/17] perf report: Extend raw dump (-D) out with switch out event type Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 04/17] perf script: Extend misc field decoding " Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 05/17] perf list: Add s390 support for detailed/verbose PMU event description Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 06/17] perf: Return proper values for user stack errors Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 07/17] perf: Fix sample_max_stack maximum check Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 08/17] perf: Remove superfluous allocation error check Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 09/17] perf trace: Support MAP_FIXED_NOREPLACE Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 10/17] perf mem: Allow all record/report options Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 11/17] perf hists browser: Clarify top/report browser help Arnaldo Carvalho de Melo
2018-04-20 14:32 ` Arnaldo Carvalho de Melo [this message]
2018-04-20 14:32 ` [PATCH 13/17] perf record: Remove suggestion to enable APIC Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 14/17] perf tools: Add '\n' at the end of parse-options error messages Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 15/17] perf tests mmap: Show which tracepoint is failing Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 16/17] perf test BPF: Fixup BPF test using epoll_pwait syscall function probe Arnaldo Carvalho de Melo
2018-04-20 14:32 ` [PATCH 17/17] coresight: Move to SPDX identifier Arnaldo Carvalho de Melo
2018-04-21  7:39 ` [GIT PULL 00/17] perf/urgent fixes and improvements Ingo Molnar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180420143227.16030-13-acme@kernel.org \
    --to=acme@kernel.org \
    --cc=acme@redhat.com \
    --cc=ak@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-perf-users@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=williams@redhat.com \
    --subject='Re: [PATCH 12/17] perf record: Remove misleading error suggestion' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).