Commit 49836f78 authored Jul 04, 2018 by Jack Henschel Committed by Arnaldo Carvalho de Melo Aug 20, 2018

perf parser: Improve error message for PMU address filters



This is the second version of a patch that improves the error message of
the perf events parser when the PMU hardware does not support address
filters.

Previously, the perf returned the following error:

  $ perf record -e intel_pt// --filter 'filter sys_write'
  --filter option should follow a -e tracepoint or HW tracer option

This implies there is some syntax error present in the command line,
which is not true. Rather, notify the user that the CPU does not have
support for this feature.

For example, Intel chips based on the Broadwell micro-archticture have
the Intel PT PMU, but do not support address filtering.

Now, perf prints the following error message:

  $ perf record -e intel_pt// --filter 'filter sys_write'
  This CPU does not support address filtering

Signed-off-by: Jack Henschel <jackdev@mailbox.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180704121345.19025-1-jackdev@mailbox.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent da15fc2f

tools/perf/util/parse-events.c

+10 −10

Original line number	Diff line number	Diff line
		@@ -1991,8 +1991,11 @@ static int set_filter(struct perf_evsel evsel, const void arg)
		int nr_addr_filters = 0;
		struct perf_pmu *pmu = NULL;

		if (evsel == NULL)
		goto err;
		if (evsel == NULL) {
		fprintf(stderr,
		"--filter option should follow a -e tracepoint or HW tracer option\n");
		return -1;
		}

		if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
		if (perf_evsel__append_tp_filter(evsel, str) < 0) {
		@@ -2014,8 +2017,11 @@ static int set_filter(struct perf_evsel evsel, const void arg)
		perf_pmu__scan_file(pmu, "nr_addr_filters",
		"%d", &nr_addr_filters);

		if (!nr_addr_filters)
		goto err;
		if (!nr_addr_filters) {
		fprintf(stderr,
		"This CPU does not support address filtering\n");
		return -1;
		}

		if (perf_evsel__append_addr_filter(evsel, str) < 0) {
		fprintf(stderr,
		@@ -2024,12 +2030,6 @@ static int set_filter(struct perf_evsel evsel, const void arg)
		}

		return 0;

		err:
		fprintf(stderr,
		"--filter option should follow a -e tracepoint or HW tracer option\n");

		return -1;
		}

		int parse_filter(const struct option opt, const char str,

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