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Date: Wed, 31 May 2023 10:03:28 -0400
From: "Liang, Kan" <kan.liang@...ux.intel.com>
To: Ian Rogers <irogers@...gle.com>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Rob Herring <robh@...nel.org>,
Ravi Bangoria <ravi.bangoria@....com>,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
Thomas Richter <tmricht@...ux.ibm.com>
Subject: Re: [PATCH v1] perf parse-events: Wildcard most "numeric" events
On 2023-05-30 7:27 p.m., Ian Rogers wrote:
> Numeric events are either raw events or those with ABI defined numbers
> matched by the lexer. All raw events that don't specify a PMU type
> should wildcard match on hybrid systems. So "cycles" should match each
> PMU type with an extended type, not just PERF_TYPE_HARDWARE.
>
> Change wildcard matching to add the event if wildcard PMU scanning
> fails, there will be no extended type but this best matches previous
> behavior.
>
> Only set the extended type when the event type supports it and when
> perf_pmus__supports_extended_type is true. This new function returns
> true if >1 core PMU and avoids potential errors on older kernels.
>
> Try to always pass a PMU for parse_events_add_numeric, update
> evsel__compute_group_pmu_name as software events will have a PMU and
> pmu_name rather than NULL. This makes homogeneous and heterogeneous
> PMU events more similar.
>
> Set a parse events error if a hardware term's PMU lookup fails to
> provide extra diagnostics.
I think the patch tries to fix two issues on hybrid.
- Perf fails to create hardware events for each core PMU when the PMU
type is not specified.
- When splitting a group with multiple PMUs, SW events should be created
for each new sub-groups.
It works well for the first issue:
Before
# perf_old stat -e cycles ./hybrid.sh
Performance counter stats for './hybrid.sh':
420,833,619 cycles
1.219129587 seconds time elapsed
With the patch
# perf stat -e cycles ./hybrid.sh
Performance counter stats for './hybrid.sh':
420,691,729 cpu_core/cycles/
613,038,584 cpu_atom/cycles/
(98.47%)
1.219057759 seconds time elapsed
For the second issue, the new behavior doesn't seem correct for me.
Before
./perf_old stat -e '{data_read,faults}' --no-merge -a sleep 1
WARNING: events were regrouped to match PMUs
WARNING: grouped events cpus do not match.
Events with CPUs not matching the leader will be removed from the group.
anon group { data_read, faults }
Performance counter stats for 'system wide':
70.05 MiB data_read [uncore_imc_free_running_0]
55.82 MiB data_read [uncore_imc_free_running_1]
77 faults
1.004216885 seconds time elapsed
With the patch
# ./perf stat -e '{data_read,faults}' --no-merge -a sleep 1
WARNING: events were regrouped to match PMUs
WARNING: grouped events cpus do not match.
Events with CPUs not matching the leader will be removed from the group.
anon group { data_read, faults, faults }
Performance counter stats for 'system wide':
53.51 MiB data_read [uncore_imc_free_running_0]
39.04 MiB data_read [uncore_imc_free_running_1]
76 cpu_core/faults/
2 cpu_atom/faults/
The faults is a SW event, but with a core PMU prefix. I think it's wrong.
According to the -vvv information, the faults doesn't seem be regrouped
with any uncore events.
perf_event_attr:
type 1
size 136
config 0x2
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
exclude_guest 1
------------------------------------------------------------
sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0 = 5
------------------------------------------------------------
For the second issue, can we make the behavior unchanged for now?
BTW: It seems the current perf-tools-next branch has another regression
for the JSON event. The inst_retired.any should be available for both
atom and core. I believe I tried the below commands several days ago.
But it does't work now. I will check when the regression was introduced.
# ./perf stat -e inst_retired.any ./hybrid.sh
Performance counter stats for './hybrid.sh':
3,261,510,386 cpu_core/inst_retired.any/
(99.07%)
1.218858763 seconds time elapsed
Thanks,
Kan
>
> Reported-by: Kan Liang <kan.liang@...ux.intel.com>
> Fixes: 8bc75f699c14 ("perf parse-events: Support wildcards on raw events")
> Signed-off-by: Ian Rogers <irogers@...gle.com>> ---
> tools/perf/util/parse-events.c | 71 +++++++++++++++++++++-------------
> tools/perf/util/parse-events.y | 4 +-
> tools/perf/util/pmus.c | 5 +++
> tools/perf/util/pmus.h | 1 +
> 4 files changed, 53 insertions(+), 28 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 7f047ac11168..58c9f34bcd95 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -372,7 +372,7 @@ static int config_attr(struct perf_event_attr *attr,
> * contain hyphens and the longest name
> * should always be selected.
> */
> -int parse_events__decode_legacy_cache(const char *name, int pmu_type, __u64 *config)
> +int parse_events__decode_legacy_cache(const char *name, int extended_pmu_type, __u64 *config)
> {
> int len, cache_type = -1, cache_op = -1, cache_result = -1;
> const char *name_end = &name[strlen(name) + 1];
> @@ -423,8 +423,9 @@ int parse_events__decode_legacy_cache(const char *name, int pmu_type, __u64 *con
> if (cache_result == -1)
> cache_result = PERF_COUNT_HW_CACHE_RESULT_ACCESS;
>
> - *config = ((__u64)pmu_type << PERF_PMU_TYPE_SHIFT) |
> - cache_type | (cache_op << 8) | (cache_result << 16);
> + *config = cache_type | (cache_op << 8) | (cache_result << 16);
> + if (perf_pmus__supports_extended_type())
> + *config |= (__u64)extended_pmu_type << PERF_PMU_TYPE_SHIFT;
> return 0;
> }
>
> @@ -1204,11 +1205,17 @@ static int config_term_pmu(struct perf_event_attr *attr,
> const struct perf_pmu *pmu = perf_pmus__find_by_type(attr->type);
>
> if (!pmu) {
> - pr_debug("Failed to find PMU for type %d", attr->type);
> + char *err_str;
> +
> + if (asprintf(&err_str, "Failed to find PMU for type %d", attr->type) >= 0)
> + parse_events_error__handle(err, term->err_term,
> + err_str, /*help=*/NULL);
> return -EINVAL;
> }
> attr->type = PERF_TYPE_HARDWARE;
> - attr->config = ((__u64)pmu->type << PERF_PMU_TYPE_SHIFT) | term->val.num;
> + attr->config = term->val.num;
> + if (perf_pmus__supports_extended_type())
> + attr->config |= (__u64)pmu->type << PERF_PMU_TYPE_SHIFT;
> return 0;
> }
> if (term->type_term == PARSE_EVENTS__TERM_TYPE_USER ||
> @@ -1435,8 +1442,8 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
>
> static int __parse_events_add_numeric(struct parse_events_state *parse_state,
> struct list_head *list,
> - struct perf_pmu *pmu, u32 type, u64 config,
> - struct list_head *head_config)
> + struct perf_pmu *pmu, u32 type, u32 extended_type,
> + u64 config, struct list_head *head_config)
> {
> struct perf_event_attr attr;
> LIST_HEAD(config_terms);
> @@ -1446,6 +1453,10 @@ static int __parse_events_add_numeric(struct parse_events_state *parse_state,
> memset(&attr, 0, sizeof(attr));
> attr.type = type;
> attr.config = config;
> + if (extended_type && (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE)) {
> + assert(perf_pmus__supports_extended_type());
> + attr.config |= (u64)extended_type << PERF_PMU_TYPE_SHIFT;
> + };
>
> if (head_config) {
> if (config_attr(&attr, head_config, parse_state->error,
> @@ -1474,24 +1485,26 @@ int parse_events_add_numeric(struct parse_events_state *parse_state,
> struct perf_pmu *pmu = NULL;
> bool found_supported = false;
>
> - if (!wildcard)
> - return __parse_events_add_numeric(parse_state, list, /*pmu=*/NULL,
> - type, config, head_config);
> -
> /* Wildcards on numeric values are only supported by core PMUs. */
> - while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
> - int ret;
> + if (wildcard && perf_pmus__supports_extended_type()) {
> + while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
> + int ret;
>
> - if (parse_events__filter_pmu(parse_state, pmu))
> - continue;
> + found_supported = true;
> + if (parse_events__filter_pmu(parse_state, pmu))
> + continue;
>
> - found_supported = true;
> - ret = __parse_events_add_numeric(parse_state, list, pmu, pmu->type,
> - config, head_config);
> - if (ret)
> - return ret;
> + ret = __parse_events_add_numeric(parse_state, list, pmu,
> + type, pmu->type,
> + config, head_config);
> + if (ret)
> + return ret;
> + }
> + if (found_supported)
> + return 0;
> }
> - return found_supported ? 0 : -EINVAL;
> + return __parse_events_add_numeric(parse_state, list, perf_pmus__find_by_type(type),
> + type, /*extended_type=*/0, config, head_config);
> }
>
> int parse_events_add_tool(struct parse_events_state *parse_state,
> @@ -1989,7 +2002,10 @@ static int evsel__compute_group_pmu_name(struct evsel *evsel,
> {
> struct evsel *leader = evsel__leader(evsel);
> struct evsel *pos;
> - const char *group_pmu_name = evsel->pmu_name ?: "cpu";
> + const char *group_pmu_name = "cpu";
> +
> + if (evsel->core.attr.type != PERF_TYPE_SOFTWARE && evsel->pmu_name)
> + group_pmu_name = evsel->pmu_name;
>
> /*
> * Software events may be in a group with other uncore PMU events. Use
> @@ -2002,14 +2018,17 @@ static int evsel__compute_group_pmu_name(struct evsel *evsel,
> if (evsel->core.attr.type == PERF_TYPE_SOFTWARE || evsel__is_aux_event(leader)) {
> /*
> * Starting with the leader, find the first event with a named
> - * PMU. for_each_group_(member|evsel) isn't used as the list
> - * isn't yet sorted putting evsel's in the same group together.
> + * non-software PMU. for_each_group_(member|evsel) isn't used as
> + * the list isn't yet sorted putting evsel's in the same group
> + * together.
> */
> - if (leader->pmu_name) {
> + if (leader->pmu_name && leader->core.attr.type != PERF_TYPE_SOFTWARE) {
> group_pmu_name = leader->pmu_name;
> } else if (leader->core.nr_members > 1) {
> list_for_each_entry(pos, head, core.node) {
> - if (evsel__leader(pos) == leader && pos->pmu_name) {
> + if (evsel__leader(pos) == leader &&
> + pos->core.attr.type != PERF_TYPE_SOFTWARE &&
> + pos->pmu_name) {
> group_pmu_name = pos->pmu_name;
> break;
> }
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index abd6ab460e12..48c21314cf6b 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -449,7 +449,7 @@ value_sym '/' event_config '/'
> list = alloc_list();
> ABORT_ON(!list);
> err = parse_events_add_numeric(_parse_state, list, type, config, $3,
> - /*wildcard=*/false);
> + /*wildcard=*/true);
> parse_events_terms__delete($3);
> if (err) {
> free_list_evsel(list);
> @@ -468,7 +468,7 @@ value_sym sep_slash_slash_dc
> ABORT_ON(!list);
> ABORT_ON(parse_events_add_numeric(_parse_state, list, type, config,
> /*head_config=*/NULL,
> - /*wildcard=*/false));
> + /*wildcard=*/true));
> $$ = list;
> }
> |
> diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> index 53f11f6ce878..e1d0a93147e5 100644
> --- a/tools/perf/util/pmus.c
> +++ b/tools/perf/util/pmus.c
> @@ -477,6 +477,11 @@ int perf_pmus__num_core_pmus(void)
> return count;
> }
>
> +bool perf_pmus__supports_extended_type(void)
> +{
> + return perf_pmus__num_core_pmus() > 1;
> +}
> +
> struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)
> {
> struct perf_pmu *pmu = evsel->pmu;
> diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
> index 1e710720aec7..d02ffea5d3a4 100644
> --- a/tools/perf/util/pmus.h
> +++ b/tools/perf/util/pmus.h
> @@ -19,5 +19,6 @@ int perf_pmus__num_mem_pmus(void);
> void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *print_state);
> bool perf_pmus__have_event(const char *pname, const char *name);
> int perf_pmus__num_core_pmus(void);
> +bool perf_pmus__supports_extended_type(void);
>
> #endif /* __PMUS_H */
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