linux/tools/perf/util/parse-events.h
Arnaldo Carvalho de Melo 2fda5ada07 perf evsel: Introduce per event max_events property
This simply adds the field to 'struct perf_evsel' and allows setting
it via the event parser, to test it lets trace trace:

First look at where in a function that receives an evsel we can put a probe
to read how evsel->max_events was setup:

  # perf probe -x ~/bin/perf -L trace__event_handler
  <trace__event_handler@/home/acme/git/perf/tools/perf/builtin-trace.c:0>
        0  static int trace__event_handler(struct trace *trace, struct perf_evsel *evsel,
                                          union perf_event *event __maybe_unused,
                                          struct perf_sample *sample)
        3  {
        4         struct thread *thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
        5         int callchain_ret = 0;

        7         if (sample->callchain) {
        8                 callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
        9                 if (callchain_ret == 0) {
       10                         if (callchain_cursor.nr < trace->min_stack)
       11                                 goto out;
       12                         callchain_ret = 1;
                          }
                  }

See what variables we can probe at line 7:

  # perf probe -x ~/bin/perf -V trace__event_handler:7
  Available variables at trace__event_handler:7
          @<trace__event_handler+89>
                  int     callchain_ret
                  struct perf_evsel*      evsel
                  struct perf_sample*     sample
                  struct thread*  thread
                  struct trace*   trace
                  union perf_event*       event

Add a probe at that line asking for evsel->max_events to be collected and named
as "max_events":

  # perf probe -x ~/bin/perf trace__event_handler:7 'max_events=evsel->max_events'
  Added new event:
    probe_perf:trace__event_handler (on trace__event_handler:7 in /home/acme/bin/perf with max_events=evsel->max_events)

  You can now use it in all perf tools, such as:

  	perf record -e probe_perf:trace__event_handler -aR sleep 1

Now use 'perf trace', here aliased to just 'trace' and trace trace, i.e.
the first 'trace' is tracing just that 'probe_perf:trace__event_handler' event,
while the traced trace is tracing all scheduler tracepoints, will stop at two
events (--max-events 2) and will just set evsel->max_events for all the sched
tracepoints to 9, we will see the output of both traces intermixed:

  # trace -e *perf:*event_handler trace --max-events 2 -e sched:*/nr=9/
       0.000 :0/0 sched:sched_waking:comm=rcu_sched pid=10 prio=120 target_cpu=000
       0.009 :0/0 sched:sched_wakeup:comm=rcu_sched pid=10 prio=120 target_cpu=000
       0.000 trace/23949 probe_perf:trace__event_handler:(48c34a) max_events=0x9
       0.046 trace/23949 probe_perf:trace__event_handler:(48c34a) max_events=0x9
  #

Now, if the traced trace sends its output to /dev/null, we'll see just
what the first level trace outputs: that evsel->max_events is indeed
being set to 9:

  # trace -e *perf:*event_handler trace -o /dev/null --max-events 2 -e sched:*/nr=9/
       0.000 trace/23961 probe_perf:trace__event_handler:(48c34a) max_events=0x9
       0.030 trace/23961 probe_perf:trace__event_handler:(48c34a) max_events=0x9
  #

Now that we can set evsel->max_events, we can go to the next step, honour that
per-event property in 'perf trace'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-og00yasj276joem6e14l1eas@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-10-19 16:31:09 -03:00

236 lines
7.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PERF_PARSE_EVENTS_H
#define __PERF_PARSE_EVENTS_H
/*
* Parse symbolic events/counts passed in as options:
*/
#include <linux/list.h>
#include <stdbool.h>
#include <linux/types.h>
#include <linux/perf_event.h>
#include <string.h>
struct list_head;
struct perf_evsel;
struct perf_evlist;
struct parse_events_error;
struct option;
struct tracepoint_path {
char *system;
char *name;
struct tracepoint_path *next;
};
struct tracepoint_path *tracepoint_id_to_path(u64 config);
struct tracepoint_path *tracepoint_name_to_path(const char *name);
bool have_tracepoints(struct list_head *evlist);
const char *event_type(int type);
int parse_events_option(const struct option *opt, const char *str, int unset);
int parse_events(struct perf_evlist *evlist, const char *str,
struct parse_events_error *error);
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);
#define EVENTS_HELP_MAX (128*1024)
enum perf_pmu_event_symbol_type {
PMU_EVENT_SYMBOL_ERR, /* not a PMU EVENT */
PMU_EVENT_SYMBOL, /* normal style PMU event */
PMU_EVENT_SYMBOL_PREFIX, /* prefix of pre-suf style event */
PMU_EVENT_SYMBOL_SUFFIX, /* suffix of pre-suf style event */
};
struct perf_pmu_event_symbol {
char *symbol;
enum perf_pmu_event_symbol_type type;
};
enum {
PARSE_EVENTS__TERM_TYPE_NUM,
PARSE_EVENTS__TERM_TYPE_STR,
};
enum {
PARSE_EVENTS__TERM_TYPE_USER,
PARSE_EVENTS__TERM_TYPE_CONFIG,
PARSE_EVENTS__TERM_TYPE_CONFIG1,
PARSE_EVENTS__TERM_TYPE_CONFIG2,
PARSE_EVENTS__TERM_TYPE_NAME,
PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD,
PARSE_EVENTS__TERM_TYPE_SAMPLE_FREQ,
PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE,
PARSE_EVENTS__TERM_TYPE_TIME,
PARSE_EVENTS__TERM_TYPE_CALLGRAPH,
PARSE_EVENTS__TERM_TYPE_STACKSIZE,
PARSE_EVENTS__TERM_TYPE_NOINHERIT,
PARSE_EVENTS__TERM_TYPE_INHERIT,
PARSE_EVENTS__TERM_TYPE_MAX_STACK,
PARSE_EVENTS__TERM_TYPE_MAX_EVENTS,
PARSE_EVENTS__TERM_TYPE_NOOVERWRITE,
PARSE_EVENTS__TERM_TYPE_OVERWRITE,
PARSE_EVENTS__TERM_TYPE_DRV_CFG,
__PARSE_EVENTS__TERM_TYPE_NR,
};
struct parse_events_array {
size_t nr_ranges;
struct {
unsigned int start;
size_t length;
} *ranges;
};
struct parse_events_term {
char *config;
struct parse_events_array array;
union {
char *str;
u64 num;
} val;
int type_val;
int type_term;
struct list_head list;
bool used;
bool no_value;
/* error string indexes for within parsed string */
int err_term;
int err_val;
/* Coming from implicit alias */
bool weak;
};
struct parse_events_error {
int idx; /* index in the parsed string */
char *str; /* string to display at the index */
char *help; /* optional help string */
};
struct parse_events_state {
struct list_head list;
int idx;
int nr_groups;
struct parse_events_error *error;
struct perf_evlist *evlist;
struct list_head *terms;
};
void parse_events__shrink_config_terms(void);
int parse_events__is_hardcoded_term(struct parse_events_term *term);
int parse_events_term__num(struct parse_events_term **term,
int type_term, char *config, u64 num,
bool novalue,
void *loc_term, void *loc_val);
int parse_events_term__str(struct parse_events_term **term,
int type_term, char *config, char *str,
void *loc_term, void *loc_val);
int parse_events_term__sym_hw(struct parse_events_term **term,
char *config, unsigned idx);
int parse_events_term__clone(struct parse_events_term **new,
struct parse_events_term *term);
void parse_events_terms__delete(struct list_head *terms);
void parse_events_terms__purge(struct list_head *terms);
void parse_events__clear_array(struct parse_events_array *a);
int parse_events__modifier_event(struct list_head *list, char *str, bool add);
int parse_events__modifier_group(struct list_head *list, char *event_mod);
int parse_events_name(struct list_head *list, char *name);
int parse_events_add_tracepoint(struct list_head *list, int *idx,
const char *sys, const char *event,
struct parse_events_error *error,
struct list_head *head_config);
int parse_events_load_bpf(struct parse_events_state *parse_state,
struct list_head *list,
char *bpf_file_name,
bool source,
struct list_head *head_config);
/* Provide this function for perf test */
struct bpf_object;
int parse_events_load_bpf_obj(struct parse_events_state *parse_state,
struct list_head *list,
struct bpf_object *obj,
struct list_head *head_config);
int parse_events_add_numeric(struct parse_events_state *parse_state,
struct list_head *list,
u32 type, u64 config,
struct list_head *head_config);
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);
int parse_events_add_breakpoint(struct list_head *list, int *idx,
void *ptr, char *type, u64 len);
int parse_events_add_pmu(struct parse_events_state *parse_state,
struct list_head *list, char *name,
struct list_head *head_config,
bool auto_merge_stats,
bool use_alias);
int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
char *str,
struct list_head **listp);
int parse_events_copy_term_list(struct list_head *old,
struct list_head **new);
enum perf_pmu_event_symbol_type
perf_pmu__parse_check(const char *name);
void parse_events__set_leader(char *name, struct list_head *list,
struct parse_events_state *parse_state);
void parse_events_update_lists(struct list_head *list_event,
struct list_head *list_all);
void parse_events_evlist_error(struct parse_events_state *parse_state,
int idx, const char *str);
void print_events(const char *event_glob, bool name_only, bool quiet,
bool long_desc, bool details_flag);
struct event_symbol {
const char *symbol;
const char *alias;
};
extern struct event_symbol event_symbols_hw[];
extern struct event_symbol event_symbols_sw[];
void print_symbol_events(const char *event_glob, unsigned type,
struct event_symbol *syms, unsigned max,
bool name_only);
void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
bool name_only);
int print_hwcache_events(const char *event_glob, bool name_only);
void print_sdt_events(const char *subsys_glob, const char *event_glob,
bool name_only);
int is_valid_tracepoint(const char *event_string);
int valid_event_mount(const char *eventfs);
char *parse_events_formats_error_string(char *additional_terms);
void parse_events_print_error(struct parse_events_error *err,
const char *event);
#ifdef HAVE_LIBELF_SUPPORT
/*
* If the probe point starts with '%',
* or starts with "sdt_" and has a ':' but no '=',
* then it should be a SDT/cached probe point.
*/
static inline bool is_sdt_event(char *str)
{
return (str[0] == '%' ||
(!strncmp(str, "sdt_", 4) &&
!!strchr(str, ':') && !strchr(str, '=')));
}
#else
static inline bool is_sdt_event(char *str __maybe_unused)
{
return false;
}
#endif /* HAVE_LIBELF_SUPPORT */
#endif /* __PERF_PARSE_EVENTS_H */