Re: [PATCH v6] perf tools: add support for libpfm4

[Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>]

Em Wed, Apr 01, 2020 at 11:49:13AM -0700, Ian Rogers escreveu:
> From: Stephane Eranian <eranian@google.com>
> 
> This patch links perf with the libpfm4 library if it is available and
> NO_LIBPFM4 isn't passed to the build. The libpfm4 library contains hardware

Can we make this a explicit decision instead, i.e. for it to be linked
we would need to have its development files installed and -DLIBPFM4,
like we have for CORESIGHT?

  $ grep CORESIGHT tools/perf/Makefile.perf
  # Define CORESIGHT if you DO WANT support for CoreSight trace decoding.
  $

- Arnaldo

> event tables for all processors supported by perf_events. It is a helper
> library that helps convert from a symbolic event name to the event
> encoding required by the underlying kernel interface. This
> library is open-source and available from: http://perfmon2.sf.net.
> 
> With this patch, it is possible to specify full hardware events
> by name. Hardware filters are also supported. Events must be
> specified via the --pfm-events and not -e option. Both options
> are active at the same time and it is possible to mix and match:
> 
> $ perf stat --pfm-events inst_retired:any_p:c=1:i -e cycles ....
> 
> v6 is a rebase.
> v5 is a rebase.
> v4 is a rebase on git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git
>    branch perf/core and re-adds the tools/build/feature/test-libpfm4.c
>    missed in v3.
> v3 is against acme/perf/core and removes a diagnostic warning.
> v2 of this patch makes the --pfm-events man page documentation
> conditional on libpfm4 behing configured. It tidies some of the
> documentation and adds the feature test missed in the v1 patch.
> 
> Reviewed-By:Ian Rogers <irogers@google.com>
> ---
>  tools/build/Makefile.feature             |   6 +-
>  tools/build/feature/Makefile             |   7 +-
>  tools/build/feature/test-libpfm4.c       |   8 +
>  tools/perf/Documentation/Makefile        |   4 +-
>  tools/perf/Documentation/perf-record.txt |  11 +
>  tools/perf/Documentation/perf-stat.txt   |  10 +
>  tools/perf/Documentation/perf-top.txt    |  11 +
>  tools/perf/Makefile.config               |  12 ++
>  tools/perf/Makefile.perf                 |   6 +-
>  tools/perf/builtin-list.c                |  16 ++
>  tools/perf/builtin-record.c              |  20 ++
>  tools/perf/builtin-stat.c                |  21 ++
>  tools/perf/builtin-top.c                 |  20 ++
>  tools/perf/util/evsel.c                  |   2 +-
>  tools/perf/util/evsel.h                  |   1 +
>  tools/perf/util/parse-events.c           | 246 +++++++++++++++++++++++
>  tools/perf/util/parse-events.h           |   5 +
>  tools/perf/util/pmu.c                    |  11 +
>  tools/perf/util/pmu.h                    |   1 +
>  19 files changed, 410 insertions(+), 8 deletions(-)
>  create mode 100644 tools/build/feature/test-libpfm4.c
> 
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 574c2e0b9d20..08c6fe5aee2d 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -72,7 +72,8 @@ FEATURE_TESTS_BASIC :=                  \
>          setns				\
>          libaio				\
>          libzstd				\
> -        disassembler-four-args
> +        disassembler-four-args		\
> +        libpfm4
>  
>  # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list
>  # of all feature tests
> @@ -127,7 +128,8 @@ FEATURE_DISPLAY ?=              \
>           bpf			\
>           libaio			\
>           libzstd		\
> -         disassembler-four-args
> +         disassembler-four-args	\
> +         libpfm4
>  
>  # Set FEATURE_CHECK_(C|LD)FLAGS-all for all FEATURE_TESTS features.
>  # If in the future we need per-feature checks/flags for features not
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index 7ac0d8088565..573072d32545 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -67,7 +67,9 @@ FILES=                                          \
>           test-llvm.bin				\
>           test-llvm-version.bin			\
>           test-libaio.bin			\
> -         test-libzstd.bin
> +         test-libzstd.bin			\
> +         test-libpfm4.bin
> +
>  
>  FILES := $(addprefix $(OUTPUT),$(FILES))
>  
> @@ -321,6 +323,9 @@ $(OUTPUT)test-libaio.bin:
>  $(OUTPUT)test-libzstd.bin:
>  	$(BUILD) -lzstd
>  
> +$(OUTPUT)test-libpfm4.bin:
> +	$(BUILD) -lpfm
> +
>  ###############################
>  
>  clean:
> diff --git a/tools/build/feature/test-libpfm4.c b/tools/build/feature/test-libpfm4.c
> new file mode 100644
> index 000000000000..7f24df86cf09
> --- /dev/null
> +++ b/tools/build/feature/test-libpfm4.c
> @@ -0,0 +1,8 @@
> +#include <sys/types.h>
> +#include <perfmon/pfmlib.h>
> +
> +int main(void)
> +{
> +        pfm_initialize();
> +        return 0;
> +}
> diff --git a/tools/perf/Documentation/Makefile b/tools/perf/Documentation/Makefile
> index 31824d5269cc..6e54979c2124 100644
> --- a/tools/perf/Documentation/Makefile
> +++ b/tools/perf/Documentation/Makefile
> @@ -48,7 +48,7 @@ man5dir=$(mandir)/man5
>  man7dir=$(mandir)/man7
>  
>  ASCIIDOC=asciidoc
> -ASCIIDOC_EXTRA = --unsafe -f asciidoc.conf
> +ASCIIDOC_EXTRA += --unsafe -f asciidoc.conf
>  ASCIIDOC_HTML = xhtml11
>  MANPAGE_XSL = manpage-normal.xsl
>  XMLTO_EXTRA =
> @@ -59,7 +59,7 @@ HTML_REF = origin/html
>  
>  ifdef USE_ASCIIDOCTOR
>  ASCIIDOC = asciidoctor
> -ASCIIDOC_EXTRA = -a compat-mode
> +ASCIIDOC_EXTRA += -a compat-mode
>  ASCIIDOC_EXTRA += -I. -rasciidoctor-extensions
>  ASCIIDOC_EXTRA += -a mansource="perf" -a manmanual="perf Manual"
>  ASCIIDOC_HTML = xhtml5
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index b3f3b3f1c161..ad2c41f595c2 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -596,6 +596,17 @@ Make a copy of /proc/kcore and place it into a directory with the perf data file
>  Limit the sample data max size, <size> is expected to be a number with
>  appended unit character - B/K/M/G
>  
> +ifdef::HAVE_LIBPFM[]
> +--pfm-events events::
> +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net)
> +including support for event filters. For example '--pfm-events
> +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the
> +option using the comma separator. Hardware events and generic hardware
> +events cannot be mixed together. The latter must be used with the -e
> +option. The -e option and this one can be mixed and matched.  Events
> +can be grouped using the {} notation.
> +endif::HAVE_LIBPFM[]
> +
>  SEE ALSO
>  --------
>  linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-intel-pt[1]
> diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
> index 4d56586b2fb9..536952ad592c 100644
> --- a/tools/perf/Documentation/perf-stat.txt
> +++ b/tools/perf/Documentation/perf-stat.txt
> @@ -71,6 +71,16 @@ report::
>  --tid=<tid>::
>          stat events on existing thread id (comma separated list)
>  
> +ifdef::HAVE_LIBPFM[]
> +--pfm-events events::
> +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net)
> +including support for event filters. For example '--pfm-events
> +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the
> +option using the comma separator. Hardware events and generic hardware
> +events cannot be mixed together. The latter must be used with the -e
> +option. The -e option and this one can be mixed and matched.  Events
> +can be grouped using the {} notation.
> +endif::HAVE_LIBPFM[]
>  
>  -a::
>  --all-cpus::
> diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
> index 487737a725e9..9858e3640b0c 100644
> --- a/tools/perf/Documentation/perf-top.txt
> +++ b/tools/perf/Documentation/perf-top.txt
> @@ -319,6 +319,17 @@ Default is to monitor all CPUS.
>  	go straight to the histogram browser, just like 'perf top' with no events
>  	explicitely specified does.
>  
> +ifdef::HAVE_LIBPFM[]
> +--pfm-events events::
> +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net)
> +including support for event filters. For example '--pfm-events
> +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the
> +option using the comma separator. Hardware events and generic hardware
> +events cannot be mixed together. The latter must be used with the -e
> +option. The -e option and this one can be mixed and matched.  Events
> +can be grouped using the {} notation.
> +endif::HAVE_LIBPFM[]
> +
>  
>  INTERACTIVE PROMPTING KEYS
>  --------------------------
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 80e55e796be9..571aa6b1af40 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -999,6 +999,18 @@ ifdef LIBCLANGLLVM
>    endif
>  endif
>  
> +ifndef NO_LIBPFM4
> +  ifeq ($(feature-libpfm4), 1)
> +    CFLAGS += -DHAVE_LIBPFM
> +    EXTLIBS += -lpfm
> +    ASCIIDOC_EXTRA = -aHAVE_LIBPFM=1
> +    $(call detected,CONFIG_LIBPFM4)
> +  else
> +    msg := $(warning libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev);
> +    NO_LIBPFM4 := 1
> +  endif
> +endif
> +
>  # Among the variables below, these:
>  #   perfexecdir
>  #   perf_include_dir
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index d15a311408f1..9787eb3ca0a9 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -118,6 +118,8 @@ include ../scripts/utilities.mak
>  #
>  # Define LIBBPF_DYNAMIC to enable libbpf dynamic linking.
>  #
> +# Define NO_LIBPFM4 to disable libpfm4 extension.
> +#
>  
>  # As per kernel Makefile, avoid funny character set dependencies
>  unexport LC_ALL
> @@ -188,7 +190,7 @@ AWK     = awk
>  # non-config cases
>  config := 1
>  
> -NON_CONFIG_TARGETS := clean python-clean TAGS tags cscope help install-doc install-man install-html install-info install-pdf doc man html info pdf
> +NON_CONFIG_TARGETS := clean python-clean TAGS tags cscope help
>  
>  ifdef MAKECMDGOALS
>  ifeq ($(filter-out $(NON_CONFIG_TARGETS),$(MAKECMDGOALS)),)
> @@ -832,7 +834,7 @@ INSTALL_DOC_TARGETS += quick-install-doc quick-install-man quick-install-html
>  
>  # 'make doc' should call 'make -C Documentation all'
>  $(DOC_TARGETS):
> -	$(Q)$(MAKE) -C $(DOC_DIR) O=$(OUTPUT) $(@:doc=all)
> +	$(Q)$(MAKE) -C $(DOC_DIR) O=$(OUTPUT) $(@:doc=all) ASCIIDOC_EXTRA=$(ASCIIDOC_EXTRA)
>  
>  TAG_FOLDERS= . ../lib ../include
>  TAG_FILES= ../../include/uapi/linux/perf_event.h
> diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
> index 965ef017496f..5edeb428168a 100644
> --- a/tools/perf/builtin-list.c
> +++ b/tools/perf/builtin-list.c
> @@ -18,6 +18,10 @@
>  #include <subcmd/parse-options.h>
>  #include <stdio.h>
>  
> +#ifdef HAVE_LIBPFM
> +#include <perfmon/pfmlib.h>
> +#endif
> +
>  static bool desc_flag = true;
>  static bool details_flag;
>  
> @@ -56,6 +60,18 @@ int cmd_list(int argc, const char **argv)
>  	if (!raw_dump && pager_in_use())
>  		printf("\nList of pre-defined events (to be used in -e):\n\n");
>  
> +#ifdef HAVE_LIBPFM
> +	{
> +		int ret;
> +		ret = pfm_initialize();
> +		if (ret != PFM_SUCCESS) {
> +			fprintf(stderr,
> +				"warning libpfm failed to initialize: %s\n",
> +				pfm_strerror(ret));
> +		}
> +	}
> +#endif
> +
>  	if (argc == 0) {
>  		print_events(NULL, raw_dump, !desc_flag, long_desc_flag,
>  				details_flag, deprecated);
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 7d7912e121d6..7d2737f33c2e 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -64,6 +64,10 @@
>  #include <linux/zalloc.h>
>  #include <linux/bitmap.h>
>  
> +#ifdef HAVE_LIBPFM
> +#include <perfmon/pfmlib.h>
> +#endif
> +
>  struct switch_output {
>  	bool		 enabled;
>  	bool		 signal;
> @@ -2415,6 +2419,11 @@ static struct option __record_options[] = {
>  #endif
>  	OPT_CALLBACK(0, "max-size", &record.output_max_size,
>  		     "size", "Limit the maximum size of the output file", parse_output_max_size),
> +#ifdef HAVE_LIBPFM
> +	OPT_CALLBACK(0, "pfm-events", &record.evlist, "event",
> +		"libpfm4 event selector. use 'perf list' to list available events",
> +		parse_libpfm_events_option),
> +#endif
>  	OPT_END()
>  };
>  
> @@ -2455,6 +2464,17 @@ int cmd_record(int argc, const char **argv)
>  	if (rec->evlist == NULL)
>  		return -ENOMEM;
>  
> +#ifdef HAVE_LIBPFM
> +	{
> +		int ret;
> +		ret = pfm_initialize();
> +		if (ret != PFM_SUCCESS) {
> +			ui__warning("warning libpfm failed to initialize: %s\n",
> +				pfm_strerror(ret));
> +		}
> +	}
> +#endif
> +
>  	err = perf_config(perf_record_config, rec);
>  	if (err)
>  		return err;
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index ec053dc1e35c..c47eaf238f0c 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -89,6 +89,10 @@
>  #include <linux/ctype.h>
>  #include <perf/evlist.h>
>  
> +#ifdef HAVE_LIBPFM
> +#include <perfmon/pfmlib.h>
> +#endif
> +
>  #define DEFAULT_SEPARATOR	" "
>  #define FREEZE_ON_SMI_PATH	"devices/cpu/freeze_on_smi"
>  
> @@ -933,6 +937,11 @@ static struct option stat_options[] = {
>  		    "Use with 'percore' event qualifier to show the event "
>  		    "counts of one hardware thread by sum up total hardware "
>  		    "threads of same physical core"),
> +#ifdef HAVE_LIBPFM
> +	OPT_CALLBACK(0, "pfm-events", &evsel_list, "event",
> +		"libpfm4 event selector. use 'perf list' to list available events",
> +		parse_libpfm_events_option),
> +#endif
>  	OPT_END()
>  };
>  
> @@ -1871,6 +1880,18 @@ int cmd_stat(int argc, const char **argv)
>  	unsigned int interval, timeout;
>  	const char * const stat_subcommands[] = { "record", "report" };
>  
> +#ifdef HAVE_LIBPFM
> +	{
> +		int ret;
> +		ret = pfm_initialize();
> +		if (ret != PFM_SUCCESS) {
> +			fprintf(stderr,
> +				"warning libpfm failed to initialize: %s\n",
> +				pfm_strerror(ret));
> +		}
> +	}
> +#endif
> +
>  	setlocale(LC_ALL, "");
>  
>  	evsel_list = evlist__new();
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 6684d94b1398..afec285f9877 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -84,6 +84,10 @@
>  #include <linux/ctype.h>
>  #include <perf/mmap.h>
>  
> +#ifdef HAVE_LIBPFM
> +#include <perfmon/pfmlib.h>
> +#endif
> +
>  static volatile int done;
>  static volatile int resize;
>  
> @@ -1565,6 +1569,11 @@ int cmd_top(int argc, const char **argv)
>  		    "Sort the output by the event at the index n in group. "
>  		    "If n is invalid, sort by the first event. "
>  		    "WARNING: should be used on grouped events."),
> +#ifdef HAVE_LIBPFM
> +	OPT_CALLBACK(0, "pfm-events", &top.evlist, "event",
> +		"libpfm4 event selector. use 'perf list' to list available events",
> +		parse_libpfm_events_option),
> +#endif
>  	OPTS_EVSWITCH(&top.evswitch),
>  	OPT_END()
>  	};
> @@ -1578,6 +1587,17 @@ int cmd_top(int argc, const char **argv)
>  	if (status < 0)
>  		return status;
>  
> +#ifdef HAVE_LIBPFM
> +	{
> +		int ret;
> +		ret = pfm_initialize();
> +		if (ret != PFM_SUCCESS) {
> +			ui__warning("warning libpfm failed to initialize: %s\n",
> +				pfm_strerror(ret));
> +		}
> +	}
> +#endif
> +
>  	top.annotation_opts.min_pcnt = 5;
>  	top.annotation_opts.context  = 4;
>  
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index eb880efbce16..ca1b9cbf3355 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2448,7 +2448,7 @@ bool perf_evsel__fallback(struct evsel *evsel, int err,
>  
>  		/* Is there already the separator in the name. */
>  		if (strchr(name, '/') ||
> -		    strchr(name, ':'))
> +		    (strchr(name, ':') && !evsel->is_libpfm_event))
>  			sep = "";
>  
>  		if (asprintf(&new_name, "%s%su", name, sep) < 0)
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 53187c501ee8..0b6eec714e6f 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -76,6 +76,7 @@ struct evsel {
>  	bool			ignore_missing_thread;
>  	bool			forced_leader;
>  	bool			use_uncore_alias;
> +	bool			is_libpfm_event;
>  	/* parse modifier helper */
>  	int			exclude_GH;
>  	int			sample_read;
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 10107747b361..31ed184566c8 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -37,6 +37,11 @@
>  #include "util/evsel_config.h"
>  #include "util/event.h"
>  
> +#ifdef HAVE_LIBPFM
> +#include <perfmon/pfmlib_perf_event.h>
> +static void print_libpfm_events(bool name_only);
> +#endif
> +
>  #define MAX_NAME_LEN 100
>  
>  #ifdef PARSER_DEBUG
> @@ -2794,6 +2799,10 @@ void print_events(const char *event_glob, bool name_only, bool quiet_flag,
>  	print_sdt_events(NULL, NULL, name_only);
>  
>  	metricgroup__print(true, true, NULL, name_only, details_flag);
> +
> +#ifdef HAVE_LIBPFM
> +	print_libpfm_events(name_only);
> +#endif
>  }
>  
>  int parse_events__is_hardcoded_term(struct parse_events_term *term)
> @@ -3042,3 +3051,240 @@ char *parse_events_formats_error_string(char *additional_terms)
>  fail:
>  	return NULL;
>  }
> +
> +#ifdef HAVE_LIBPFM
> +static int
> +parse_libpfm_event(char *strp, struct perf_event_attr *attr)
> +{
> +	int ret;
> +
> +	ret = pfm_get_perf_event_encoding(strp, PFM_PLM0|PFM_PLM3,
> +					attr, NULL, NULL);
> +	return ret;
> +}
> +
> +int parse_libpfm_events_option(const struct option *opt, const char *str,
> +			int unset __maybe_unused)
> +{
> +	struct evlist *evlist = *(struct evlist **)opt->value;
> +	struct perf_event_attr attr;
> +	struct perf_pmu *pmu;
> +	struct evsel *evsel, *grp_leader = NULL;
> +	char *p, *q, *p_orig;
> +	const char *sep;
> +	int grp_evt = -1;
> +	int ret;
> +
> +	p_orig = p = strdup(str);
> +	if (!p)
> +		return -1;
> +	/*
> +	 * force loading of the PMU list
> +	 */
> +	perf_pmu__scan(NULL);
> +
> +	for (q = p; strsep(&p, ",{}"); q = p) {
> +		sep = p ? str + (p - p_orig - 1) : "";
> +		if (*sep == '{') {
> +			if (grp_evt > -1) {
> +				fprintf(stderr, "nested event groups not supported\n");
> +				goto error;
> +			}
> +			grp_evt++;
> +		}
> +
> +		/* no event */
> +		if (*q == '\0')
> +			continue;
> +
> +		memset(&attr, 0, sizeof(attr));
> +		event_attr_init(&attr);
> +
> +		ret = parse_libpfm_event(q, &attr);
> +		if (ret != PFM_SUCCESS) {
> +			fprintf(stderr, "failed to parse event %s : %s\n", str, pfm_strerror(ret));
> +			goto error;
> +		}
> +
> +		evsel = perf_evsel__new_idx(&attr, evlist->core.nr_entries);
> +		if (evsel == NULL)
> +			goto error;
> +
> +		evsel->name = strdup(q);
> +		if (!evsel->name) {
> +			evsel__delete(evsel);
> +			goto error;
> +		}
> +		evsel->is_libpfm_event = true;
> +
> +		pmu = perf_pmu__find_by_type((unsigned)attr.type);
> +		if (pmu)
> +			evsel->core.own_cpus = perf_cpu_map__get(pmu->cpus);
> +
> +		evlist__add(evlist, evsel);
> +
> +		if (grp_evt == 0)
> +			grp_leader = evsel;
> +
> +		if (grp_evt > -1) {
> +			evsel->leader = grp_leader;
> +			grp_leader->core.nr_members++;
> +			grp_evt++;
> +		}
> +
> +		if (*sep == '}') {
> +			if (grp_evt < 0) {
> +				fprintf(stderr, "cannot close a non-existing event group\n");
> +				goto error;
> +			}
> +			evlist->nr_groups++;
> +			grp_leader = NULL;
> +			grp_evt = -1;
> +		}
> +	}
> +	return 0;
> +error:
> +	free(p_orig);
> +	return -1;
> +}
> +
> +static const char *srcs[PFM_ATTR_CTRL_MAX]={
> +	[PFM_ATTR_CTRL_UNKNOWN] = "???",
> +	[PFM_ATTR_CTRL_PMU] = "PMU",
> +	[PFM_ATTR_CTRL_PERF_EVENT] = "perf_event",
> +};
> +
> +static void
> +print_attr_flags(pfm_event_attr_info_t *info)
> +{
> +	int n = 0;
> +
> +	if (info->is_dfl) {
> +		printf("[default] ");
> +		n++;
> +	}
> +
> +	if (info->is_precise) {
> +		printf("[precise] ");
> +		n++;
> +	}
> +
> +	if (!n)
> +		printf("- ");
> +}
> +
> +static void
> +print_libpfm_detailed_events(pfm_pmu_info_t *pinfo, pfm_event_info_t *info)
> +{
> +	pfm_event_attr_info_t ainfo;
> +	const char *src;
> +	int j, ret;
> +
> +	ainfo.size = sizeof(ainfo);
> +
> +	printf("\nName  : %s\n", info->name);
> +	printf("PMU   : %s\n", pinfo->name);
> +	printf("Desc  : %s\n", info->desc);
> +	printf("Equiv : %s\n", info->equiv ? info->equiv : "None");
> +	printf("Code  : 0x%"PRIx64"\n", info->code);
> +
> +	pfm_for_each_event_attr(j, info) {
> +		ret = pfm_get_event_attr_info(info->idx, j, PFM_OS_PERF_EVENT_EXT, &ainfo);
> +		if (ret != PFM_SUCCESS)
> +			continue;
> +
> +		if (ainfo.ctrl >= PFM_ATTR_CTRL_MAX)
> +			ainfo.ctrl = PFM_ATTR_CTRL_UNKNOWN;
> +
> +		src = srcs[ainfo.ctrl];
> +		switch(ainfo.type) {
> +		case PFM_ATTR_UMASK:
> +			printf("Umask : 0x%02"PRIx64" : %s: [%s] : ", ainfo.code, src, ainfo.name);
> +			print_attr_flags(&ainfo);
> +			printf(": %s\n", ainfo.desc);
> +			break;
> +		case PFM_ATTR_MOD_BOOL:
> +			printf("Modif : %s: [%s] : %s (boolean)\n", src, ainfo.name, ainfo.desc);
> +			break;
> +		case PFM_ATTR_MOD_INTEGER:
> +			printf("Modif : %s: [%s] : %s (integer)\n", src, ainfo.name, ainfo.desc);
> +			break;
> +		case PFM_ATTR_NONE:
> +		case PFM_ATTR_RAW_UMASK:
> +		case PFM_ATTR_MAX:
> +		default:
> +			printf("Attr  : %s: [%s] : %s\n", src, ainfo.name, ainfo.desc);
> +		}
> +	}
> +}
> +
> +/*
> + * list all pmu::event:umask, pmu::event
> + * printed events may not be all valid combinations of umask for an event
> + */
> +static void
> +print_libpfm_simplified_events(pfm_pmu_info_t *pinfo, pfm_event_info_t *info)
> +{
> +	pfm_event_attr_info_t ainfo;
> +	int j, ret;
> +	int um = 0;
> +
> +	ainfo.size = sizeof(ainfo);
> +
> +	pfm_for_each_event_attr(j, info) {
> +		ret = pfm_get_event_attr_info(info->idx, j, PFM_OS_PERF_EVENT_EXT, &ainfo);
> +		if (ret != PFM_SUCCESS)
> +			continue;
> +
> +		if (ainfo.type != PFM_ATTR_UMASK)
> +			continue;
> +
> +		printf("%s::%s:%s\n", pinfo->name, info->name, ainfo.name);
> +		um++;
> +	}
> +	if (um == 0)
> +		printf("%s::%s\n", pinfo->name, info->name);
> +}
> +
> +static void
> +print_libpfm_events(bool name_only)
> +{
> +	pfm_event_info_t info;
> +	pfm_pmu_info_t pinfo;
> +	pfm_event_attr_info_t ainfo;
> +	int i, p, ret;
> +
> +	/* initialize to zero to indicate ABI version */
> +	info.size  = sizeof(info);
> +	pinfo.size = sizeof(pinfo);
> +	ainfo.size = sizeof(ainfo);
> +
> +	putchar('\n');
> +
> +	pfm_for_all_pmus(p) {
> +		ret = pfm_get_pmu_info(p, &pinfo);
> +		if (ret != PFM_SUCCESS)
> +			continue;
> +
> +		/* ony print events that are supported by host HW */
> +		if (!pinfo.is_present)
> +			continue;
> +
> +		/* handled by perf directly */
> +		if (pinfo.pmu == PFM_PMU_PERF_EVENT)
> +			continue;
> +
> +		for (i = pinfo.first_event; i != -1; i = pfm_get_event_next(i)) {
> +
> +			ret = pfm_get_event_info(i, PFM_OS_PERF_EVENT_EXT, &info);
> +			if (ret != PFM_SUCCESS)
> +				continue;
> +
> +			if (!name_only)
> +				print_libpfm_detailed_events(&pinfo, &info);
> +			else
> +				print_libpfm_simplified_events(&pinfo, &info);
> +		}
> +	}
> +}
> +#endif
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index 27596cbd0ba0..84d4799c9a31 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -37,6 +37,11 @@ int parse_events_terms(struct list_head *terms, const char *str);
>  int parse_filter(const struct option *opt, const char *str, int unset);
>  int exclude_perf(const struct option *opt, const char *arg, int unset);
>  
> +#ifdef HAVE_LIBPFM
> +extern int parse_libpfm_events_option(const struct option *opt, const char *str,
> +				int unset);
> +#endif
> +
>  #define EVENTS_HELP_MAX (128*1024)
>  
>  enum perf_pmu_event_symbol_type {
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index ef6a63f3d386..5e918ca740c6 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -869,6 +869,17 @@ static struct perf_pmu *pmu_find(const char *name)
>  	return NULL;
>  }
>  
> +struct perf_pmu *perf_pmu__find_by_type(unsigned int type)
> +{
> +	struct perf_pmu *pmu;
> +
> +	list_for_each_entry(pmu, &pmus, list)
> +		if (pmu->type == type)
> +			return pmu;
> +
> +	return NULL;
> +}
> +
>  struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
>  {
>  	/*
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 5fb3f16828df..de3b868d912c 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -65,6 +65,7 @@ struct perf_pmu_alias {
>  };
>  
>  struct perf_pmu *perf_pmu__find(const char *name);
> +struct perf_pmu *perf_pmu__find_by_type(unsigned int type);
>  int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
>  		     struct list_head *head_terms,
>  		     struct parse_events_error *error);
> -- 
> 2.26.0.rc2.310.g2932bb562d-goog
> 

-- 

- Arnaldo