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Date:   Mon, 8 Feb 2021 15:59:05 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     kan.liang@linux.intel.com
Cc:     peterz@infradead.org, mingo@kernel.org,
        linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de,
        namhyung@kernel.org, jolsa@redhat.com, ak@linux.intel.com,
        yao.jin@linux.intel.com, alexander.shishkin@linux.intel.com,
        adrian.hunter@intel.com
Subject: Re: [PATCH 35/49] perf parse-events: Create two hybrid hardware
 events
Message-ID: <20210208185905.GL920417@kernel.org>
References: <1612797946-18784-1-git-send-email-kan.liang@linux.intel.com>
 <1612797946-18784-36-git-send-email-kan.liang@linux.intel.com>
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Em Mon, Feb 08, 2021 at 07:25:32AM -0800, kan.liang@linux.intel.com escreveu:
> From: Jin Yao <yao.jin@linux.intel.com>
> 
> For hardware events, they have pre-defined configs. The kernel
> needs to know where the event comes from (e.g. from cpu_core pmu
> or from cpu_atom pmu). But the perf type 'PERF_TYPE_HARDWARE'
> can't carry pmu information.
> 
> So the kernel introduces a new type 'PERF_TYPE_HARDWARE_PMU'.
> The new attr.config layout for PERF_TYPE_HARDWARE_PMU is:
> 
> 0xDD000000AA
> AA: original hardware event ID
> DD: PMU type ID
> 
> PMU type ID is retrieved from sysfs. For example,
> 
> cat /sys/devices/cpu_atom/type
> 10
> 
> cat /sys/devices/cpu_core/type
> 4
> 
> When enabling a hybrid hardware event without specified pmu, such as,
> 'perf stat -e cycles -a', two events are created automatically. One
> is for atom, the other is for core.

please move the command output two chars to the right, otherwise lines
with --- may confuse some scripts.

> root@otcpl-adl-s-2:~# ./perf stat -e cycles -vv -a -- sleep 1
> 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
>   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                             6
>   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
> cycles: 0: 1254337 1001292571 1001292571
> cycles: 1: 2595141 1001279813 1001279813
> cycles: 2: 134853 1001276406 1001276406
> cycles: 3: 81119 1001271089 1001271089
> cycles: 4: 251353 1001264678 1001264678
> cycles: 5: 415593 1001259163 1001259163
> cycles: 6: 129643 1001265312 1001265312
> cycles: 7: 80289 1001258979 1001258979
> cycles: 8: 169983 1001251207 1001251207
> cycles: 9: 81981 1001245487 1001245487
> cycles: 10: 4116221 1001245537 1001245537
> cycles: 11: 85531 1001253097 1001253097
> cycles: 12: 3969132 1001254270 1001254270
> cycles: 13: 96006 1001254691 1001254691
> cycles: 14: 385004 1001244971 1001244971
> cycles: 15: 394446 1001251437 1001251437
> cycles: 0: 427330 1001253457 1001253457
> cycles: 1: 444043 1001255914 1001255914
> cycles: 2: 97285 1001253555 1001253555
> cycles: 3: 92071 1001260556 1001260556
> cycles: 4: 86292 1001249896 1001249896
> cycles: 5: 236851 1001238979 1001238979
> cycles: 6: 100081 1001239792 1001239792
> cycles: 7: 72836 1001243276 1001243276
> cycles: 14240632 16020168708 16020168708
> cycles: 1556789 8009995425 8009995425
> 
>  Performance counter stats for 'system wide':
> 
>         14,240,632      cycles
>          1,556,789      cycles
> 
>        1.002261231 seconds time elapsed
> 
> type 6 is PERF_TYPE_HARDWARE_PMU.
> 0x4 in 0x400000000 indicates the cpu_core pmu.
> 0xa in 0xa00000000 indicates the cpu_atom pmu.
> 
> Reviewed-by: Andi Kleen <ak@linux.intel.com>
> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> ---
>  tools/perf/util/parse-events.c | 73 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
> 
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 81a6fce..1e767dc 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -446,6 +446,24 @@ static int config_attr(struct perf_event_attr *attr,
>  		       struct parse_events_error *err,
>  		       config_term_func_t config_term);
>  
> +static void config_hybrid_attr(struct perf_event_attr *attr,
> +			       int type, int pmu_type)
> +{
> +	/*
> +	 * attr.config layout:
> +	 * PERF_TYPE_HARDWARE_PMU:     0xDD000000AA
> +	 *                             AA: hardware event ID
> +	 *                             DD: PMU type ID
> +	 * PERF_TYPE_HW_CACHE_PMU:     0xDD00CCBBAA
> +	 *                             AA: hardware cache ID
> +	 *                             BB: hardware cache op ID
> +	 *                             CC: hardware cache op result ID
> +	 *                             DD: PMU type ID
> +	 */
> +	attr->type = type;
> +	attr->config = attr->config | ((__u64)pmu_type << PERF_PMU_TYPE_SHIFT);
> +}
> +
>  int parse_events_add_cache(struct list_head *list, int *idx,
>  			   char *type, char *op_result1, char *op_result2,
>  			   struct parse_events_error *err,
> @@ -1409,6 +1427,47 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
>  					    err, head_config);
>  }
>  
> +static int create_hybrid_hw_event(struct parse_events_state *parse_state,
> +				  struct list_head *list,
> +				  struct perf_event_attr *attr,
> +				  struct perf_pmu *pmu)
> +{
> +	struct evsel *evsel;
> +	__u32 type = attr->type;
> +	__u64 config = attr->config;
> +
> +	config_hybrid_attr(attr, PERF_TYPE_HARDWARE_PMU, pmu->type);
> +	evsel = __add_event(list, &parse_state->idx, attr, true, NULL,
> +			    pmu, NULL, 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_numeric(struct parse_events_state *parse_state,
> +			      struct list_head *list,
> +			      struct perf_event_attr *attr,
> +			      bool *hybrid)
> +{
> +	struct perf_pmu *pmu;
> +	int ret;
> +
> +	*hybrid = false;
> +	perf_pmu__for_each_hybrid_pmus(pmu) {
> +		*hybrid = true;
> +		ret = create_hybrid_hw_event(parse_state, list, attr, pmu);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  int parse_events_add_numeric(struct parse_events_state *parse_state,
>  			     struct list_head *list,
>  			     u32 type, u64 config,
> @@ -1416,6 +1475,8 @@ int parse_events_add_numeric(struct parse_events_state *parse_state,
>  {
>  	struct perf_event_attr attr;
>  	LIST_HEAD(config_terms);
> +	bool hybrid;
> +	int ret;
>  
>  	memset(&attr, 0, sizeof(attr));
>  	attr.type = type;
> @@ -1430,6 +1491,18 @@ int parse_events_add_numeric(struct parse_events_state *parse_state,
>  			return -ENOMEM;
>  	}
>  
> +	/*
> +	 * Skip the software dummy event.
> +	 */
> +	if (type != PERF_TYPE_SOFTWARE) {
> +		if (!perf_pmu__hybrid_exist())
> +			perf_pmu__scan(NULL);
> +
> +		ret = add_hybrid_numeric(parse_state, list, &attr, &hybrid);
> +		if (hybrid)
> +			return ret;
> +	}
> +
>  	return add_event(list, &parse_state->idx, &attr,
>  			 get_config_name(head_config), &config_terms);
>  }
> -- 
> 2.7.4
> 

-- 

- Arnaldo