[PATCH 36/49] perf parse-events: Create two hybrid cache events

From: kan . liang
Date: Mon Feb 08 2021 - 13:03:41 EST


From: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>

For cache events, they have pre-defined configs. The kernel needs
to know where the cache event comes from (e.g. from cpu_core pmu
or from cpu_atom pmu). But the perf type 'PERF_TYPE_HW_CACHE'
can't carry pmu information.

So the kernel introduces a new type 'PERF_TYPE_HW_CACHE_PMU'.

The new attr.config layout for PERF_TYPE_HW_CACHE_PMU is

0xDD00CCBBAA
0xAA: hardware cache ID
0xBB: hardware cache op ID
0xCC: hardware cache op result ID
0xDD: PMU type ID

Similar as hardware event, PMU type ID is retrieved from sysfs.

When enabling a hybrid cache event without specified pmu, such as,
'perf stat -e L1-dcache-loads -a', two events are created
automatically. One is for atom, the other is for core.

root@otcpl-adl-s-2:~# ./perf stat -e L1-dcache-loads -vv -a -- sleep 1
Control descriptor is not initialized
------------------------------------------------------------
perf_event_attr:
type 7
size 120
config 0x400000000
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 0x8 = 3
sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 4
sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 = 5
sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 = 7
sys_perf_event_open: pid -1 cpu 4 group_fd -1 flags 0x8 = 8
sys_perf_event_open: pid -1 cpu 5 group_fd -1 flags 0x8 = 9
sys_perf_event_open: pid -1 cpu 6 group_fd -1 flags 0x8 = 10
sys_perf_event_open: pid -1 cpu 7 group_fd -1 flags 0x8 = 11
sys_perf_event_open: pid -1 cpu 8 group_fd -1 flags 0x8 = 12
sys_perf_event_open: pid -1 cpu 9 group_fd -1 flags 0x8 = 13
sys_perf_event_open: pid -1 cpu 10 group_fd -1 flags 0x8 = 14
sys_perf_event_open: pid -1 cpu 11 group_fd -1 flags 0x8 = 15
sys_perf_event_open: pid -1 cpu 12 group_fd -1 flags 0x8 = 16
sys_perf_event_open: pid -1 cpu 13 group_fd -1 flags 0x8 = 17
sys_perf_event_open: pid -1 cpu 14 group_fd -1 flags 0x8 = 18
sys_perf_event_open: pid -1 cpu 15 group_fd -1 flags 0x8 = 19
------------------------------------------------------------
perf_event_attr:
type 7
size 120
config 0xa00000000
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 16 group_fd -1 flags 0x8 = 20
sys_perf_event_open: pid -1 cpu 17 group_fd -1 flags 0x8 = 21
sys_perf_event_open: pid -1 cpu 18 group_fd -1 flags 0x8 = 22
sys_perf_event_open: pid -1 cpu 19 group_fd -1 flags 0x8 = 23
sys_perf_event_open: pid -1 cpu 20 group_fd -1 flags 0x8 = 24
sys_perf_event_open: pid -1 cpu 21 group_fd -1 flags 0x8 = 25
sys_perf_event_open: pid -1 cpu 22 group_fd -1 flags 0x8 = 26
sys_perf_event_open: pid -1 cpu 23 group_fd -1 flags 0x8 = 27
L1-dcache-loads: 0: 77398 1001256700 1001256700
L1-dcache-loads: 1: 5286 1001255101 1001255101
L1-dcache-loads: 2: 26432 1001280449 1001280449
L1-dcache-loads: 3: 2853 1001274145 1001274145
L1-dcache-loads: 4: 521391 1001304618 1001304618
L1-dcache-loads: 5: 1231 1001287686 1001287686
L1-dcache-loads: 6: 1237 1001284439 1001284439
L1-dcache-loads: 7: 1384 1001278646 1001278646
L1-dcache-loads: 8: 1238 1001274988 1001274988
L1-dcache-loads: 9: 1225 1001267988 1001267988
L1-dcache-loads: 10: 88066 1001301843 1001301843
L1-dcache-loads: 11: 1243 1001308922 1001308922
L1-dcache-loads: 12: 1231 1001313498 1001313498
L1-dcache-loads: 13: 12880 1001306597 1001306597
L1-dcache-loads: 14: 21244 1001293603 1001293603
L1-dcache-loads: 15: 1225 1001287958 1001287958
L1-dcache-loads: 0: 1244 1001289333 1001289333
L1-dcache-loads: 1: 1361 1001288189 1001288189
L1-dcache-loads: 2: 1226 1001285926 1001285926
L1-dcache-loads: 3: 1226 1001289431 1001289431
L1-dcache-loads: 4: 1239 1001283299 1001283299
L1-dcache-loads: 5: 10500 1001318113 1001318113
L1-dcache-loads: 6: 1226 1001315332 1001315332
L1-dcache-loads: 7: 1226 1001325366 1001325366
L1-dcache-loads: 765564 16020577181 16020577181
L1-dcache-loads: 19248 8010394989 8010394989

Performance counter stats for 'system wide':

765,564 L1-dcache-loads
19,248 L1-dcache-loads

1.002255760 seconds time elapsed

type 7 is PERF_TYPE_HW_CACHE_PMU.
0x4 in 0x400000000 indicates the cpu_core pmu.
0xa in 0xa00000000 indicates the cpu_atom pmu.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
tools/perf/util/parse-events.c | 54 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 1e767dc..28d356e 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -464,6 +464,48 @@ static void config_hybrid_attr(struct perf_event_attr *attr,
attr->config = attr->config | ((__u64)pmu_type << PERF_PMU_TYPE_SHIFT);
}

+static int create_hybrid_cache_event(struct list_head *list, int *idx,
+ struct perf_event_attr *attr, char *name,
+ struct list_head *config_terms,
+ struct perf_pmu *pmu)
+{
+ struct evsel *evsel;
+ __u32 type = attr->type;
+ __u64 config = attr->config;
+
+ config_hybrid_attr(attr, PERF_TYPE_HW_CACHE_PMU, pmu->type);
+ evsel = __add_event(list, idx, attr, true, name,
+ pmu, config_terms, false, NULL);
+ if (evsel)
+ evsel->pmu_name = strdup(pmu->name);
+ else
+ return -ENOMEM;
+
+ attr->type = type;
+ attr->config = config;
+ return 0;
+}
+
+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)
+{
+ struct perf_pmu *pmu;
+ int ret;
+
+ *hybrid = false;
+ perf_pmu__for_each_hybrid_pmus(pmu) {
+ *hybrid = true;
+ ret = create_hybrid_cache_event(list, idx, attr, name,
+ config_terms, pmu);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
int parse_events_add_cache(struct list_head *list, int *idx,
char *type, char *op_result1, char *op_result2,
struct parse_events_error *err,
@@ -474,7 +516,8 @@ int parse_events_add_cache(struct list_head *list, int *idx,
char name[MAX_NAME_LEN], *config_name;
int cache_type = -1, cache_op = -1, cache_result = -1;
char *op_result[2] = { op_result1, op_result2 };
- int i, n;
+ int i, n, ret;
+ bool hybrid;

/*
* No fallback - if we cannot get a clear cache type
@@ -534,6 +577,15 @@ int parse_events_add_cache(struct list_head *list, int *idx,
if (get_config_terms(head_config, &config_terms))
return -ENOMEM;
}
+
+ if (!perf_pmu__hybrid_exist())
+ perf_pmu__scan(NULL);
+
+ ret = add_hybrid_cache(list, idx, &attr, config_name ? : name,
+ &config_terms, &hybrid);
+ if (hybrid)
+ return ret;
+
return add_event(list, idx, &attr, config_name ? : name, &config_terms);
}

--
2.7.4