Re: [PATCH v2 11/27] perf parse-events: Support hardware events inside PMU

[Jiri Olsa]

On Thu, Mar 11, 2021 at 03:07:26PM +0800, Jin Yao wrote:
> On hybrid platform, some hardware events are only available
> on a specific pmu. For example, 'L1-dcache-load-misses' is only
> available on 'cpu_core' pmu. And even for the event which can be
> available on both pmus, the user also may want to just enable
> one event. So now following syntax is supported:
> 
> cpu_core/<hardware event>/
> cpu_core/<hardware cache event>/
> cpu_core/<pmu event>/
> 
> cpu_atom/<hardware event>/
> cpu_atom/<hardware cache event>/
> cpu_atom/<pmu event>/
> 
> It limits the event to be enabled only on a specified pmu.
> 
> The patch uses this idea, for example, if we use "cpu_core/LLC-loads/",
> in parse_events_add_pmu(), term->config is "LLC-loads".

hum, I don't understand how this doest not work even now,
I assume both cpu_core and cpu_atom have sysfs device directory
with events/ directory right?

and whatever is defined in events we allow in parsing syntax..

why can't we treat them like 2 separated pmus?

thanks,
jirka

> 
> We create a new "parse_events_state" with the pmu_name and use
> parse_events__scanner to scan the term->config (the string "LLC-loads"
> in this example). The parse_events_add_cache() will be called during
> parsing. The parse_state->pmu_name is used to identify the pmu
> where the event is enabled.
> 
> Let's see examples:
> 
>   root@ssp-pwrt-002:~# ./perf stat -e cpu_core/cycles/,cpu_core/LLC-loads/ -vv -- ./triad_loop
>   Control descriptor is not initialized
>   ------------------------------------------------------------
>   perf_event_attr:
>     type                             6
>     size                             120
>     config                           0x400000000
>     sample_type                      IDENTIFIER
>     read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
>     disabled                         1
>     inherit                          1
>     enable_on_exec                   1
>     exclude_guest                    1
>   ------------------------------------------------------------
>   sys_perf_event_open: pid 7267  cpu -1  group_fd -1  flags 0x8 = 3
>   ------------------------------------------------------------
>   perf_event_attr:
>     type                             7
>     size                             120
>     config                           0x400000002
>     sample_type                      IDENTIFIER
>     read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
>     disabled                         1
>     inherit                          1
>     enable_on_exec                   1
>     exclude_guest                    1
>   ------------------------------------------------------------
>   sys_perf_event_open: pid 7267  cpu -1  group_fd -1  flags 0x8 = 4
>   cycles: 0: 449252097 297999924 297999924
>   LLC-loads: 0: 1857 297999924 297999924
>   cycles: 449252097 297999924 297999924
>   LLC-loads: 1857 297999924 297999924
> 
>    Performance counter stats for './triad_loop':
> 
>          449,252,097      cpu_core/cycles/
>                1,857      cpu_core/LLC-loads/
> 
>          0.298898415 seconds time elapsed
> 
>   root@ssp-pwrt-002:~# ./perf stat -e cpu_atom/cycles/,cpu_atom/LLC-loads/ -vv -- taskset -c 16 ./triad_loop
>   Control descriptor is not initialized
>   ------------------------------------------------------------
>   perf_event_attr:
>     type                             6
>     size                             120
>     config                           0xa00000000
>     sample_type                      IDENTIFIER
>     read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
>     disabled                         1
>     inherit                          1
>     enable_on_exec                   1
>     exclude_guest                    1
>   ------------------------------------------------------------
>   sys_perf_event_open: pid 7339  cpu -1  group_fd -1  flags 0x8 = 3
>   ------------------------------------------------------------
>   perf_event_attr:
>     type                             7
>     size                             120
>     config                           0xa00000002
>     sample_type                      IDENTIFIER
>     read_format                      TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
>     disabled                         1
>     inherit                          1
>     enable_on_exec                   1
>     exclude_guest                    1
>   ------------------------------------------------------------
>   sys_perf_event_open: pid 7339  cpu -1  group_fd -1  flags 0x8 = 4
>   cycles: 0: 602020010 343657939 342553275
>   LLC-loads: 0: 3537 343657939 342553275
>   cycles: 603961400 343657939 342553275
>   LLC-loads: 3548 343657939 342553275
> 
>    Performance counter stats for 'taskset -c 16 ./triad_loop':
> 
>          603,961,400      cpu_atom/cycles/                                              (99.68%)
>                3,548      cpu_atom/LLC-loads/                                           (99.68%)
> 
>          0.344904585 seconds time elapsed
> 
> Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> ---
>  tools/perf/util/parse-events.c | 100 +++++++++++++++++++++++++++++++--
>  tools/perf/util/parse-events.h |   6 +-
>  tools/perf/util/parse-events.y |  21 ++-----
>  3 files changed, 105 insertions(+), 22 deletions(-)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 09e42245f71a..30435adc7a7b 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -489,7 +489,8 @@ static int create_hybrid_cache_event(struct list_head *list, int *idx,
>  static int add_hybrid_cache(struct list_head *list, int *idx,
>  			    struct perf_event_attr *attr, char *name,
>  			    struct list_head *config_terms,
> -			    bool *hybrid)
> +			    bool *hybrid,
> +			    struct parse_events_state *parse_state)
>  {
>  	struct perf_pmu *pmu;
>  	int ret;
> @@ -497,6 +498,11 @@ static int add_hybrid_cache(struct list_head *list, int *idx,
>  	*hybrid = false;
>  	perf_pmu__for_each_hybrid_pmu(pmu) {
>  		*hybrid = true;
> +		 if (parse_state->pmu_name &&
> +		     strcmp(parse_state->pmu_name, pmu->name)) {
> +			continue;
> +		}
> +
>  		ret = create_hybrid_cache_event(list, idx, attr, name,
>  						config_terms, pmu);
>  		if (ret)
> @@ -509,7 +515,8 @@ static int add_hybrid_cache(struct list_head *list, int *idx,
>  int parse_events_add_cache(struct list_head *list, int *idx,
>  			   char *type, char *op_result1, char *op_result2,
>  			   struct parse_events_error *err,
> -			   struct list_head *head_config)
> +			   struct list_head *head_config,
> +			   struct parse_events_state *parse_state)
>  {
>  	struct perf_event_attr attr;
>  	LIST_HEAD(config_terms);
> @@ -582,7 +589,7 @@ int parse_events_add_cache(struct list_head *list, int *idx,
>  		perf_pmu__scan(NULL);
>  
>  	ret = add_hybrid_cache(list, idx, &attr, config_name ? : name,
> -			       &config_terms, &hybrid);
> +			       &config_terms, &hybrid, parse_state);
>  	if (hybrid)
>  		return ret;
>  
> @@ -1512,6 +1519,11 @@ static int add_hybrid_numeric(struct parse_events_state *parse_state,
>  	*hybrid = false;
>  	perf_pmu__for_each_hybrid_pmu(pmu) {
>  		*hybrid = true;
> +		if (parse_state->pmu_name &&
> +		    strcmp(parse_state->pmu_name, pmu->name)) {
> +			continue;
> +		}
> +
>  		ret = create_hybrid_hw_event(parse_state, list, attr, pmu);
>  		if (ret)
>  			return ret;
> @@ -1578,6 +1590,10 @@ static bool config_term_percore(struct list_head *config_terms)
>  	return false;
>  }
>  
> +static int parse_events_with_hybrid_pmu(struct parse_events_state *parse_state,
> +			      const char *str, char *name, bool *found,
> +			      struct list_head *list);
> +
>  int parse_events_add_pmu(struct parse_events_state *parse_state,
>  			 struct list_head *list, char *name,
>  			 struct list_head *head_config,
> @@ -1589,7 +1605,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>  	struct perf_pmu *pmu;
>  	struct evsel *evsel;
>  	struct parse_events_error *err = parse_state->error;
> -	bool use_uncore_alias;
> +	bool use_uncore_alias, found;
>  	LIST_HEAD(config_terms);
>  
>  	if (verbose > 1) {
> @@ -1605,6 +1621,22 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>  		fprintf(stderr, "' that may result in non-fatal errors\n");
>  	}
>  
> +	if (head_config && perf_pmu__is_hybrid(name)) {
> +		struct parse_events_term *term;
> +		int ret;
> +
> +		list_for_each_entry(term, head_config, list) {
> +			if (!term->config)
> +				continue;
> +			ret = parse_events_with_hybrid_pmu(parse_state,
> +							   term->config,
> +							   name, &found,
> +							   list);
> +			if (found)
> +				return ret;
> +		}
> +	}
> +
>  	pmu = parse_state->fake_pmu ?: perf_pmu__find(name);
>  	if (!pmu) {
>  		char *err_str;
> @@ -1713,12 +1745,19 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
>  	struct perf_pmu *pmu = NULL;
>  	int ok = 0;
>  
> +        if (parse_state->pmu_name) {
> +                list = alloc_list();
> +                if (!list)
> +                        return -1;
> +                *listp = list;
> +                return 0;
> +        }
> +
>  	*listp = NULL;
>  	/* Add it for all PMUs that support the alias */
> -	list = malloc(sizeof(struct list_head));
> +	list = alloc_list();
>  	if (!list)
>  		return -1;
> -	INIT_LIST_HEAD(list);
>  	while ((pmu = perf_pmu__scan(pmu)) != NULL) {
>  		struct perf_pmu_alias *alias;
>  
> @@ -2284,6 +2323,44 @@ int parse_events_terms(struct list_head *terms, const char *str)
>  	return ret;
>  }
>  
> +static int list_num(struct list_head *list)
> +{
> +	struct list_head *pos;
> +	int n = 0;
> +
> +	list_for_each(pos, list)
> +		n++;
> +
> +	return n;
> +}
> +
> +static int parse_events_with_hybrid_pmu(struct parse_events_state *parse_state,
> +					const char *str, char *pmu_name,
> +					bool *found, struct list_head *list)
> +{
> +	struct parse_events_state ps = {
> +		.list		= LIST_HEAD_INIT(ps.list),
> +		.stoken		= PE_START_EVENTS,
> +		.pmu_name	= pmu_name,
> +		.idx		= parse_state->idx,
> +	};
> +	int ret;
> +
> +	*found = false;
> +	ret = parse_events__scanner(str, &ps);
> +	perf_pmu__parse_cleanup();
> +
> +	if (!ret) {
> +		if (!list_empty(&ps.list)) {
> +			*found = true;
> +			list_splice(&ps.list, list);
> +			parse_state->idx = list_num(list);
> +		}
> +	}
> +
> +	return ret;
> +}
> +
>  int __parse_events(struct evlist *evlist, const char *str,
>  		   struct parse_events_error *err, struct perf_pmu *fake_pmu)
>  {
> @@ -3307,3 +3384,14 @@ char *parse_events_formats_error_string(char *additional_terms)
>  fail:
>  	return NULL;
>  }
> +
> +struct list_head *alloc_list(void)
> +{
> +	struct list_head *list = malloc(sizeof(*list));
> +
> +	if (!list)
> +		return NULL;
> +
> +	INIT_LIST_HEAD(list);
> +	return list;
> +}
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index e80c9b74f2f2..39c7121a4659 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -138,6 +138,7 @@ struct parse_events_state {
>  	struct list_head	  *terms;
>  	int			   stoken;
>  	struct perf_pmu		  *fake_pmu;
> +	char			  *pmu_name;
>  };
>  
>  void parse_events__handle_error(struct parse_events_error *err, int idx,
> @@ -188,7 +189,8 @@ int parse_events_add_tool(struct parse_events_state *parse_state,
>  int parse_events_add_cache(struct list_head *list, int *idx,
>  			   char *type, char *op_result1, char *op_result2,
>  			   struct parse_events_error *error,
> -			   struct list_head *head_config);
> +			   struct list_head *head_config,
> +			   struct parse_events_state *parse_state);
>  int parse_events_add_breakpoint(struct list_head *list, int *idx,
>  				u64 addr, char *type, u64 len);
>  int parse_events_add_pmu(struct parse_events_state *parse_state,
> @@ -242,6 +244,8 @@ char *parse_events_formats_error_string(char *additional_terms);
>  void parse_events_print_error(struct parse_events_error *err,
>  			      const char *event);
>  
> +struct list_head *alloc_list(void);
> +
>  #ifdef HAVE_LIBELF_SUPPORT
>  /*
>   * If the probe point starts with '%',
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index d57ac86ce7ca..e0e68c3da9e4 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -26,18 +26,6 @@ do { \
>  		YYABORT; \
>  } while (0)
>  
> -static struct list_head* alloc_list(void)
> -{
> -	struct list_head *list;
> -
> -	list = malloc(sizeof(*list));
> -	if (!list)
> -		return NULL;
> -
> -	INIT_LIST_HEAD(list);
> -	return list;
> -}
> -
>  static void free_list_evsel(struct list_head* list_evsel)
>  {
>  	struct evsel *evsel, *tmp;
> @@ -454,7 +442,8 @@ PE_NAME_CACHE_TYPE '-' PE_NAME_CACHE_OP_RESULT '-' PE_NAME_CACHE_OP_RESULT opt_e
>  
>  	list = alloc_list();
>  	ABORT_ON(!list);
> -	err = parse_events_add_cache(list, &parse_state->idx, $1, $3, $5, error, $6);
> +	err = parse_events_add_cache(list, &parse_state->idx, $1, $3, $5, error, $6,
> +				parse_state);
>  	parse_events_terms__delete($6);
>  	free($1);
>  	free($3);
> @@ -475,7 +464,8 @@ PE_NAME_CACHE_TYPE '-' PE_NAME_CACHE_OP_RESULT opt_event_config
>  
>  	list = alloc_list();
>  	ABORT_ON(!list);
> -	err = parse_events_add_cache(list, &parse_state->idx, $1, $3, NULL, error, $4);
> +	err = parse_events_add_cache(list, &parse_state->idx, $1, $3, NULL, error, $4,
> +				parse_state);
>  	parse_events_terms__delete($4);
>  	free($1);
>  	free($3);
> @@ -495,7 +485,8 @@ PE_NAME_CACHE_TYPE opt_event_config
>  
>  	list = alloc_list();
>  	ABORT_ON(!list);
> -	err = parse_events_add_cache(list, &parse_state->idx, $1, NULL, NULL, error, $2);
> +	err = parse_events_add_cache(list, &parse_state->idx, $1, NULL, NULL, error, $2,
> +				parse_state);
>  	parse_events_terms__delete($2);
>  	free($1);
>  	if (err) {
> -- 
> 2.17.1
>