[PATCH] perf tools: Emit clearer message for sys_perf_event_open ENOENT return

[PATCH] perf tools: Emit clearer message for sys_perf_event_open ENOENT return

[David Ahern]

Resend of patch sent back in January 2011 in light of recent confusion around
unsupported events for a given platform.

Improve sys_perf_event_open ENOENT return handling in top and record, just
like 5a3446b does for stat.

Retry of Arnaldo's patch using ui_warning instead of die which allows the
fallback from hardware cycles to software clock.

Signed-off-by: David Ahern <daahern@cisco.com>
---
 tools/perf/builtin-record.c |    7 +++++++
 tools/perf/builtin-top.c    |    8 ++++++++
 2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6febcc1..cac275e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -282,6 +282,9 @@ try_again:
 			else if (err ==  ENODEV && cpu_list) {
 				die("No such device - did you specify"
 					" an out-of-range profile CPU?\n");
+			} else if (err ==  ENOENT) {
+				ui__warning("%s event is not supported.\n",
+					    event_name(pos));
 			} else if (err == EINVAL && sample_id_all_avail) {
 				/*
 				 * Old kernel, no attr->sample_id_type_all field
@@ -307,6 +310,10 @@ try_again:
 				attr->config = PERF_COUNT_SW_CPU_CLOCK;
 				goto try_again;
 			}
+
+			if (err == ENOENT)
+				exit(1);
+
 			printf("\n");
 			error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
 			      err, strerror(err));
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 80c9e06..109e1a0 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -852,6 +852,10 @@ try_again:
 				die("Permission error - are you root?\n"
 					"\t Consider tweaking"
 					" /proc/sys/kernel/perf_event_paranoid.\n");
+			else if (err == ENOENT)
+				ui__warning("%s event is not supported.\n",
+					    event_name(counter));
+
 			/*
 			 * If it's cycles then fall back to hrtimer
 			 * based cpu-clock-tick sw counter, which
@@ -867,6 +871,10 @@ try_again:
 				attr->config = PERF_COUNT_SW_CPU_CLOCK;
 				goto try_again;
 			}
+
+			if (err == ENOENT)
+				exit(1);
+
 			printf("\n");
 			error("sys_perf_event_open() syscall returned with %d "
 			      "(%s).  /bin/dmesg may provide additional information.\n",
-- 
1.7.4

[tip:perf/core] perf tools: Emit clearer message for sys_perf_event_open ENOENT return

[tip-bot for David Ahern]

Commit-ID:  ca6a42586fae639ff9e5285d9bdc550fcb1b8d41
Gitweb:     http://git.kernel.org/tip/ca6a42586fae639ff9e5285d9bdc550fcb1b8d41
Author:     David Ahern <daahern@cisco.com>
AuthorDate: Fri, 25 Mar 2011 13:11:11 -0600
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 29 Mar 2011 13:40:27 -0300

perf tools: Emit clearer message for sys_perf_event_open ENOENT return

Resend of patch sent back in January 2011 in light of recent confusion around
unsupported events for a given platform.

Improve sys_perf_event_open ENOENT return handling in top and record, just
like 5a3446b does for stat.

Retry of Arnaldo's patch using ui_warning instead of die which allows the
fallback from hardware cycles to software clock.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
LKML-Reference: <1301080271-20945-1-git-send-email-daahern@cisco.com>
Signed-off-by: David Ahern <daahern@cisco.com>
[ committer note: Some adjustments to make it apply to newer codebase ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-record.c |   10 +++++++++-
 tools/perf/builtin-top.c    |    6 ++++++
 2 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 623695e..db6adec 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -301,11 +301,19 @@ try_again:
 					&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {
 
 				if (verbose)
-					warning(" ... trying to fall back to cpu-clock-ticks\n");
+					ui__warning("The cycles event is not supported, "
+						    "trying to fall back to cpu-clock-ticks\n");
 				attr->type = PERF_TYPE_SOFTWARE;
 				attr->config = PERF_COUNT_SW_CPU_CLOCK;
 				goto try_again;
 			}
+
+			if (err == ENOENT) {
+				ui__warning("The %s event is not supported.\n",
+					    event_name(pos));
+				exit(EXIT_FAILURE);
+			}
+
 			printf("\n");
 			error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
 			      err, strerror(err));
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 935fc4f..fc1273e 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -870,6 +870,12 @@ try_again:
 				goto try_again;
 			}
 
+			if (err == ENOENT) {
+				ui__warning("The %s event is not supported.\n",
+					    event_name(counter));
+				goto out_err;
+			}
+
 			ui__warning("The sys_perf_event_open() syscall "
 				    "returned with %d (%s).  /bin/dmesg "
 				    "may provide additional information.\n"