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linux/tools/perf/util/evsel.h
Song Liu 7fac83aaf2 perf stat: Introduce 'bperf' to share hardware PMCs with BPF 
The perf tool uses performance monitoring counters (PMCs) to monitor
system performance. The PMCs are limited hardware resources. For
example, Intel CPUs have 3x fixed PMCs and 4x programmable PMCs per cpu.

Modern data center systems use these PMCs in many different ways: system
level monitoring, (maybe nested) container level monitoring, per process
monitoring, profiling (in sample mode), etc. In some cases, there are
more active perf_events than available hardware PMCs. To allow all
perf_events to have a chance to run, it is necessary to do expensive
time multiplexing of events.

On the other hand, many monitoring tools count the common metrics
(cycles, instructions). It is a waste to have multiple tools create
multiple perf_events of "cycles" and occupy multiple PMCs.

bperf tries to reduce such wastes by allowing multiple perf_events of
"cycles" or "instructions" (at different scopes) to share PMUs. Instead
of having each perf-stat session to read its own perf_events, bperf uses
BPF programs to read the perf_events and aggregate readings to BPF maps.
Then, the perf-stat session(s) reads the values from these BPF maps.

Please refer to the comment before the definition of bperf_ops for the
description of bperf architecture.

bperf is off by default. To enable it, pass --bpf-counters option to
perf-stat. bperf uses a BPF hashmap to share information about BPF
programs and maps used by bperf. This map is pinned to bpffs. The
default path is /sys/fs/bpf/perf_attr_map. The user could change the
path with option --bpf-attr-map.

Committer testing:

  # dmesg|grep "Performance Events" -A5
  [    0.225277] Performance Events: Fam17h+ core perfctr, AMD PMU driver.
  [    0.225280] ... version:                0
  [    0.225280] ... bit width:              48
  [    0.225281] ... generic registers:      6
  [    0.225281] ... value mask:             0000ffffffffffff
  [    0.225281] ... max period:             00007fffffffffff
  #
  #  for a in $(seq 6) ; do perf stat -a -e cycles,instructions sleep 100000 & done
  [1] 2436231
  [2] 2436232
  [3] 2436233
  [4] 2436234
  [5] 2436235
  [6] 2436236
  # perf stat -a -e cycles,instructions sleep 0.1

   Performance counter stats for 'system wide':

         310,326,987      cycles                                                        (41.87%)
         236,143,290      instructions              #    0.76  insn per cycle           (41.87%)

         0.100800885 seconds time elapsed

  #

We can see that the counters were enabled for this workload 41.87% of
the time.

Now with --bpf-counters:

  #  for a in $(seq 32) ; do perf stat --bpf-counters -a -e cycles,instructions sleep 100000 & done
  [1] 2436514
  [2] 2436515
  [3] 2436516
  [4] 2436517
  [5] 2436518
  [6] 2436519
  [7] 2436520
  [8] 2436521
  [9] 2436522
  [10] 2436523
  [11] 2436524
  [12] 2436525
  [13] 2436526
  [14] 2436527
  [15] 2436528
  [16] 2436529
  [17] 2436530
  [18] 2436531
  [19] 2436532
  [20] 2436533
  [21] 2436534
  [22] 2436535
  [23] 2436536
  [24] 2436537
  [25] 2436538
  [26] 2436539
  [27] 2436540
  [28] 2436541
  [29] 2436542
  [30] 2436543
  [31] 2436544
  [32] 2436545
  #
  # ls -la /sys/fs/bpf/perf_attr_map
  -rw-------. 1 root root 0 Mar 23 14:53 /sys/fs/bpf/perf_attr_map
  # bpftool map | grep bperf | wc -l
  64
  #

  # bpftool map | tail
  1265: percpu_array  name accum_readings  flags 0x0
  	key 4B  value 24B  max_entries 1  memlock 4096B
  1266: hash  name filter  flags 0x0
  	key 4B  value 4B  max_entries 1  memlock 4096B
  1267: array  name bperf_fo.bss  flags 0x400
  	key 4B  value 8B  max_entries 1  memlock 4096B
  	btf_id 996
  	pids perf(2436545)
  1268: percpu_array  name accum_readings  flags 0x0
  	key 4B  value 24B  max_entries 1  memlock 4096B
  1269: hash  name filter  flags 0x0
  	key 4B  value 4B  max_entries 1  memlock 4096B
  1270: array  name bperf_fo.bss  flags 0x400
  	key 4B  value 8B  max_entries 1  memlock 4096B
  	btf_id 997
  	pids perf(2436541)
  1285: array  name pid_iter.rodata  flags 0x480
  	key 4B  value 4B  max_entries 1  memlock 4096B
  	btf_id 1017  frozen
  	pids bpftool(2437504)
  1286: array  flags 0x0
  	key 4B  value 32B  max_entries 1  memlock 4096B
  #
  # bpftool map dump id 1268 | tail
  value (CPU 21):
  8f f3 bc ca 00 00 00 00  80 fd 2a d1 4d 00 00 00
  80 fd 2a d1 4d 00 00 00
  value (CPU 22):
  7e d5 64 4d 00 00 00 00  a4 8a 2e ee 4d 00 00 00
  a4 8a 2e ee 4d 00 00 00
  value (CPU 23):
  a7 78 3e 06 01 00 00 00  b2 34 94 f6 4d 00 00 00
  b2 34 94 f6 4d 00 00 00
  Found 1 element
  # bpftool map dump id 1268 | tail
  value (CPU 21):
  c6 8b d9 ca 00 00 00 00  20 c6 fc 83 4e 00 00 00
  20 c6 fc 83 4e 00 00 00
  value (CPU 22):
  9c b4 d2 4d 00 00 00 00  3e 0c df 89 4e 00 00 00
  3e 0c df 89 4e 00 00 00
  value (CPU 23):
  18 43 66 06 01 00 00 00  5b 69 ed 83 4e 00 00 00
  5b 69 ed 83 4e 00 00 00
  Found 1 element
  # bpftool map dump id 1268 | tail
  value (CPU 21):
  f2 6e db ca 00 00 00 00  92 67 4c ba 4e 00 00 00
  92 67 4c ba 4e 00 00 00
  value (CPU 22):
  dc 8e e1 4d 00 00 00 00  d9 32 7a c5 4e 00 00 00
  d9 32 7a c5 4e 00 00 00
  value (CPU 23):
  bd 2b 73 06 01 00 00 00  7c 73 87 bf 4e 00 00 00
  7c 73 87 bf 4e 00 00 00
  Found 1 element
  #

  # perf stat --bpf-counters -a -e cycles,instructions sleep 0.1

   Performance counter stats for 'system wide':

       119,410,122      cycles
       152,105,479      instructions              #    1.27  insn per cycle

       0.101395093 seconds time elapsed

  #

See? We had the counters enabled all the time.

Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20210316211837.910506-2-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-03-23 17:46:44 -03:00

457 lines
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PERF_EVSEL_H
#define __PERF_EVSEL_H 1
#include <linux/list.h>
#include <stdbool.h>
#include <sys/types.h>
#include <linux/perf_event.h>
#include <linux/types.h>
#include <internal/evsel.h>
#include <perf/evsel.h>
#include "symbol_conf.h"
#include <internal/cpumap.h>
struct bpf_object;
struct cgroup;
struct perf_counts;
struct perf_stat_evsel;
union perf_event;
struct bpf_counter_ops;
struct target;
struct hashmap;
struct bperf_leader_bpf;
struct bperf_follower_bpf;
typedef int (evsel__sb_cb_t)(union perf_event *event, void *data);
enum perf_tool_event {
PERF_TOOL_NONE = 0,
PERF_TOOL_DURATION_TIME = 1,
};
/** struct evsel - event selector
*
* @evlist - evlist this evsel is in, if it is in one.
* @core - libperf evsel object
* @name - Can be set to retain the original event name passed by the user,
* so that when showing results in tools such as 'perf stat', we
* show the name used, not some alias.
* @id_pos: the position of the event id (PERF_SAMPLE_ID or
* PERF_SAMPLE_IDENTIFIER) in a sample event i.e. in the array of
* struct perf_record_sample
* @is_pos: the position (counting backwards) of the event id (PERF_SAMPLE_ID or
* PERF_SAMPLE_IDENTIFIER) in a non-sample event i.e. if sample_id_all
* is used there is an id sample appended to non-sample events
* @priv: And what is in its containing unnamed union are tool specific
*/
struct evsel {
struct perf_evsel core;
struct evlist *evlist;
off_t id_offset;
int idx;
int id_pos;
int is_pos;
unsigned int sample_size;
/*
* These fields can be set in the parse-events code or similar.
* Please check evsel__clone() to copy them properly so that
* they can be released properly.
*/
struct {
char *name;
char *group_name;
const char *pmu_name;
struct tep_event *tp_format;
char *filter;
unsigned long max_events;
double scale;
const char *unit;
struct cgroup *cgrp;
enum perf_tool_event tool_event;
/* parse modifier helper */
int exclude_GH;
int sample_read;
bool snapshot;
bool per_pkg;
bool percore;
bool precise_max;
bool use_uncore_alias;
bool is_libpfm_event;
bool auto_merge_stats;
bool collect_stat;
bool weak_group;
int bpf_fd;
struct bpf_object *bpf_obj;
};
/*
* metric fields are similar, but needs more care as they can have
* references to other metric (evsel).
*/
const char * metric_expr;
const char * metric_name;
struct evsel **metric_events;
struct evsel *metric_leader;
void *handler;
struct perf_counts *counts;
struct perf_counts *prev_raw_counts;
unsigned long nr_events_printed;
struct perf_stat_evsel *stats;
void *priv;
u64 db_id;
bool uniquified_name;
bool supported;
bool needs_swap;
bool disabled;
bool no_aux_samples;
bool immediate;
bool tracking;
bool ignore_missing_thread;
bool forced_leader;
bool cmdline_group_boundary;
bool merged_stat;
bool reset_group;
bool errored;
struct hashmap *per_pkg_mask;
struct evsel *leader;
struct list_head config_terms;
int err;
int cpu_iter;
struct {
evsel__sb_cb_t *cb;
void *data;
} side_band;
/*
* For reporting purposes, an evsel sample can have a callchain
* synthesized from AUX area data. Keep track of synthesized sample
* types here. Note, the recorded sample_type cannot be changed because
* it is needed to continue to parse events.
* See also evsel__has_callchain().
*/
__u64 synth_sample_type;
/*
* bpf_counter_ops serves two use cases:
* 1. perf-stat -b counting events used byBPF programs
* 2. perf-stat --use-bpf use BPF programs to aggregate counts
*/
struct bpf_counter_ops *bpf_counter_ops;
/* for perf-stat -b */
struct list_head bpf_counter_list;
/* for perf-stat --use-bpf */
int bperf_leader_prog_fd;
int bperf_leader_link_fd;
union {
struct bperf_leader_bpf *leader_skel;
struct bperf_follower_bpf *follower_skel;
};
};
struct perf_missing_features {
bool sample_id_all;
bool exclude_guest;
bool mmap2;
bool cloexec;
bool clockid;
bool clockid_wrong;
bool lbr_flags;
bool write_backward;
bool group_read;
bool ksymbol;
bool bpf;
bool aux_output;
bool branch_hw_idx;
bool cgroup;
bool data_page_size;
bool code_page_size;
bool weight_struct;
};
extern struct perf_missing_features perf_missing_features;
struct perf_cpu_map;
struct target;
struct thread_map;
struct record_opts;
static inline struct perf_cpu_map *evsel__cpus(struct evsel *evsel)
{
return perf_evsel__cpus(&evsel->core);
}
static inline int evsel__nr_cpus(struct evsel *evsel)
{
return evsel__cpus(evsel)->nr;
}
void perf_counts_values__scale(struct perf_counts_values *count,
bool scale, s8 *pscaled);
void evsel__compute_deltas(struct evsel *evsel, int cpu, int thread,
struct perf_counts_values *count);
int evsel__object_config(size_t object_size,
int (*init)(struct evsel *evsel),
void (*fini)(struct evsel *evsel));
struct perf_pmu *evsel__find_pmu(struct evsel *evsel);
bool evsel__is_aux_event(struct evsel *evsel);
struct evsel *evsel__new_idx(struct perf_event_attr *attr, int idx);
static inline struct evsel *evsel__new(struct perf_event_attr *attr)
{
return evsel__new_idx(attr, 0);
}
struct evsel *evsel__clone(struct evsel *orig);
struct evsel *evsel__newtp_idx(const char *sys, const char *name, int idx);
/*
* Returns pointer with encoded error via <linux/err.h> interface.
*/
static inline struct evsel *evsel__newtp(const char *sys, const char *name)
{
return evsel__newtp_idx(sys, name, 0);
}
struct evsel *evsel__new_cycles(bool precise);
struct tep_event *event_format__new(const char *sys, const char *name);
void evsel__init(struct evsel *evsel, struct perf_event_attr *attr, int idx);
void evsel__exit(struct evsel *evsel);
void evsel__delete(struct evsel *evsel);
struct callchain_param;
void evsel__config(struct evsel *evsel, struct record_opts *opts,
struct callchain_param *callchain);
void evsel__config_callchain(struct evsel *evsel, struct record_opts *opts,
struct callchain_param *callchain);
int __evsel__sample_size(u64 sample_type);
void evsel__calc_id_pos(struct evsel *evsel);
bool evsel__is_cache_op_valid(u8 type, u8 op);
#define EVSEL__MAX_ALIASES 8
extern const char *evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX][EVSEL__MAX_ALIASES];
extern const char *evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX][EVSEL__MAX_ALIASES];
extern const char *evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX][EVSEL__MAX_ALIASES];
extern const char *evsel__hw_names[PERF_COUNT_HW_MAX];
extern const char *evsel__sw_names[PERF_COUNT_SW_MAX];
int __evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result, char *bf, size_t size);
const char *evsel__name(struct evsel *evsel);
const char *evsel__group_name(struct evsel *evsel);
int evsel__group_desc(struct evsel *evsel, char *buf, size_t size);
void __evsel__set_sample_bit(struct evsel *evsel, enum perf_event_sample_format bit);
void __evsel__reset_sample_bit(struct evsel *evsel, enum perf_event_sample_format bit);
#define evsel__set_sample_bit(evsel, bit) \
__evsel__set_sample_bit(evsel, PERF_SAMPLE_##bit)
#define evsel__reset_sample_bit(evsel, bit) \
__evsel__reset_sample_bit(evsel, PERF_SAMPLE_##bit)
void evsel__set_sample_id(struct evsel *evsel, bool use_sample_identifier);
void arch_evsel__set_sample_weight(struct evsel *evsel);
int evsel__set_filter(struct evsel *evsel, const char *filter);
int evsel__append_tp_filter(struct evsel *evsel, const char *filter);
int evsel__append_addr_filter(struct evsel *evsel, const char *filter);
int evsel__enable_cpu(struct evsel *evsel, int cpu);
int evsel__enable(struct evsel *evsel);
int evsel__disable(struct evsel *evsel);
int evsel__disable_cpu(struct evsel *evsel, int cpu);
int evsel__open_per_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, int cpu);
int evsel__open_per_thread(struct evsel *evsel, struct perf_thread_map *threads);
int evsel__open(struct evsel *evsel, struct perf_cpu_map *cpus,
struct perf_thread_map *threads);
void evsel__close(struct evsel *evsel);
struct perf_sample;
void *evsel__rawptr(struct evsel *evsel, struct perf_sample *sample, const char *name);
u64 evsel__intval(struct evsel *evsel, struct perf_sample *sample, const char *name);
static inline char *evsel__strval(struct evsel *evsel, struct perf_sample *sample, const char *name)
{
return evsel__rawptr(evsel, sample, name);
}
struct tep_format_field;
u64 format_field__intval(struct tep_format_field *field, struct perf_sample *sample, bool needs_swap);
struct tep_format_field *evsel__field(struct evsel *evsel, const char *name);
#define evsel__match(evsel, t, c) \
(evsel->core.attr.type == PERF_TYPE_##t && \
evsel->core.attr.config == PERF_COUNT_##c)
static inline bool evsel__match2(struct evsel *e1, struct evsel *e2)
{
return (e1->core.attr.type == e2->core.attr.type) &&
(e1->core.attr.config == e2->core.attr.config);
}
int evsel__read_counter(struct evsel *evsel, int cpu, int thread);
int __evsel__read_on_cpu(struct evsel *evsel, int cpu, int thread, bool scale);
/**
* evsel__read_on_cpu - Read out the results on a CPU and thread
*
* @evsel - event selector to read value
* @cpu - CPU of interest
* @thread - thread of interest
*/
static inline int evsel__read_on_cpu(struct evsel *evsel, int cpu, int thread)
{
return __evsel__read_on_cpu(evsel, cpu, thread, false);
}
/**
* evsel__read_on_cpu_scaled - Read out the results on a CPU and thread, scaled
*
* @evsel - event selector to read value
* @cpu - CPU of interest
* @thread - thread of interest
*/
static inline int evsel__read_on_cpu_scaled(struct evsel *evsel, int cpu, int thread)
{
return __evsel__read_on_cpu(evsel, cpu, thread, true);
}
int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
struct perf_sample *sample);
int evsel__parse_sample_timestamp(struct evsel *evsel, union perf_event *event,
u64 *timestamp);
static inline struct evsel *evsel__next(struct evsel *evsel)
{
return list_entry(evsel->core.node.next, struct evsel, core.node);
}
static inline struct evsel *evsel__prev(struct evsel *evsel)
{
return list_entry(evsel->core.node.prev, struct evsel, core.node);
}
/**
* evsel__is_group_leader - Return whether given evsel is a leader event
*
* @evsel - evsel selector to be tested
*
* Return %true if @evsel is a group leader or a stand-alone event
*/
static inline bool evsel__is_group_leader(const struct evsel *evsel)
{
return evsel->leader == evsel;
}
/**
* evsel__is_group_event - Return whether given evsel is a group event
*
* @evsel - evsel selector to be tested
*
* Return %true iff event group view is enabled and @evsel is a actual group
* leader which has other members in the group
*/
static inline bool evsel__is_group_event(struct evsel *evsel)
{
if (!symbol_conf.event_group)
return false;
return evsel__is_group_leader(evsel) && evsel->core.nr_members > 1;
}
bool evsel__is_function_event(struct evsel *evsel);
static inline bool evsel__is_bpf_output(struct evsel *evsel)
{
return evsel__match(evsel, SOFTWARE, SW_BPF_OUTPUT);
}
static inline bool evsel__is_clock(struct evsel *evsel)
{
return evsel__match(evsel, SOFTWARE, SW_CPU_CLOCK) ||
evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK);
}
bool evsel__fallback(struct evsel *evsel, int err, char *msg, size_t msgsize);
int evsel__open_strerror(struct evsel *evsel, struct target *target,
int err, char *msg, size_t size);
static inline int evsel__group_idx(struct evsel *evsel)
{
return evsel->idx - evsel->leader->idx;
}
/* Iterates group WITHOUT the leader. */
#define for_each_group_member(_evsel, _leader) \
for ((_evsel) = list_entry((_leader)->core.node.next, struct evsel, core.node); \
(_evsel) && (_evsel)->leader == (_leader); \
(_evsel) = list_entry((_evsel)->core.node.next, struct evsel, core.node))
/* Iterates group WITH the leader. */
#define for_each_group_evsel(_evsel, _leader) \
for ((_evsel) = _leader; \
(_evsel) && (_evsel)->leader == (_leader); \
(_evsel) = list_entry((_evsel)->core.node.next, struct evsel, core.node))
static inline bool evsel__has_branch_callstack(const struct evsel *evsel)
{
return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK;
}
static inline bool evsel__has_branch_hw_idx(const struct evsel *evsel)
{
return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX;
}
static inline bool evsel__has_callchain(const struct evsel *evsel)
{
/*
* For reporting purposes, an evsel sample can have a recorded callchain
* or a callchain synthesized from AUX area data.
*/
return evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN ||
evsel->synth_sample_type & PERF_SAMPLE_CALLCHAIN;
}
static inline bool evsel__has_br_stack(const struct evsel *evsel)
{
/*
* For reporting purposes, an evsel sample can have a recorded branch
* stack or a branch stack synthesized from AUX area data.
*/
return evsel->core.attr.sample_type & PERF_SAMPLE_BRANCH_STACK ||
evsel->synth_sample_type & PERF_SAMPLE_BRANCH_STACK;
}
static inline bool evsel__is_dummy_event(struct evsel *evsel)
{
return (evsel->core.attr.type == PERF_TYPE_SOFTWARE) &&
(evsel->core.attr.config == PERF_COUNT_SW_DUMMY);
}
struct perf_env *evsel__env(struct evsel *evsel);
int evsel__store_ids(struct evsel *evsel, struct evlist *evlist);
void evsel__zero_per_pkg(struct evsel *evsel);
#endif /* __PERF_EVSEL_H */
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