linux-kernel - Re: [PATCH v5 12/26] perf parse-events: Support event inside hybrid pmu

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Date:   Mon, 26 Apr 2021 08:56:28 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Jiri Olsa <jolsa@...hat.com>
Cc:     acme@...nel.org, jolsa@...nel.org, peterz@...radead.org,
        mingo@...hat.com, alexander.shishkin@...ux.intel.com,
        Linux-kernel@...r.kernel.org, ak@...ux.intel.com,
        kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v5 12/26] perf parse-events: Support event inside hybrid
 pmu

Hi Jiri,

On 4/26/2021 12:17 AM, Jiri Olsa wrote:
> On Fri, Apr 23, 2021 at 01:35:27PM +0800, Jin Yao wrote:
> 
> SNIP
> 
>> +static int parse_events__inside_hybrid_pmu(struct parse_events_state *parse_state,
>> +					   struct list_head *list, char *name,
>> +					   struct list_head *head_config)
>> +{
>> +	struct parse_events_term *term;
>> +	int ret = -1;
>> +
>> +	if (parse_state->fake_pmu || !head_config || list_empty(head_config) ||
>> +	    !perf_pmu__is_hybrid(name)) {
>> +		return -1;
>> +	}
>> +
>> +	/*
>> +	 * More than one term in list.
>> +	 */
>> +	if (head_config->next && head_config->next->next != head_config)
>> +		return -1;
>> +
>> +	term = list_first_entry(head_config, struct parse_events_term, list);
>> +	if (term && term->config && strcmp(term->config, "event")) {
> 
> so 'event' is set only for HW events, I don't see it being for other
> types.. also should the check be !strcmp ?
> 

For some HW events, such as branch-instructions, branch-misses and other HW events which are defined 
under /sys/devices/cpu_core/events, the term->config is "event". For these events, we don't need to 
do the second parsing. So I just use 'strcmp(term->config, "event")' to avoid the second parsing.

If we check with !strcmp, the second parsing will be executed but the result after parsing should be 
empty.

> also please add some tests for cache events with pmu syntax
> 

OK, I will add new test case for that.

Thanks
Jin Yao

> jirka
> 
>> +		ret = parse_events__with_hybrid_pmu(parse_state, term->config,
>> +						    name, list);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   int parse_events_add_pmu(struct parse_events_state *parse_state,
>>   			 struct list_head *list, char *name,
>>   			 struct list_head *head_config,
>> @@ -1567,6 +1598,11 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>>   	if (pmu->default_config && get_config_chgs(pmu, head_config, &config_terms))
>>   		return -ENOMEM;
>>   
>> +	if (!parse_events__inside_hybrid_pmu(parse_state, list, name,
>> +					     head_config)) {
>> +		return 0;
>> +	}
>> +
>>   	if (!parse_state->fake_pmu && perf_pmu__config(pmu, &attr, head_config, parse_state->error)) {
>>   		struct evsel_config_term *pos, *tmp;
>>   
>> @@ -2183,6 +2219,33 @@ int parse_events_terms(struct list_head *terms, const char *str)
>>   	return ret;
>>   }
>>   
>> +static int parse_events__with_hybrid_pmu(struct parse_events_state *parse_state,
>> +					 const char *str, char *pmu_name,
>> +					 struct list_head *list)
>> +{
>> +	struct parse_events_state ps = {
>> +		.list            = LIST_HEAD_INIT(ps.list),
>> +		.stoken          = PE_START_EVENTS,
>> +		.hybrid_pmu_name = pmu_name,
>> +		.idx             = parse_state->idx,
>> +	};
>> +	int ret;
>> +
>> +	ret = parse_events__scanner(str, &ps);
>> +	perf_pmu__parse_cleanup();
>> +
>> +	if (!ret) {
>> +		if (!list_empty(&ps.list)) {
>> +			list_splice(&ps.list, list);
>> +			parse_state->idx = ps.idx;
>> +			return 0;
>> +		} else
>> +			return -1;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   int __parse_events(struct evlist *evlist, const char *str,
>>   		   struct parse_events_error *err, struct perf_pmu *fake_pmu)
>>   {
>> -- 
>> 2.17.1
>>
>