Re: [PATCH v3 12/27] perf parse-events: Support no alias assigned event inside hybrid PMU

[Jin, Yao]

Hi Jiri,

On 4/9/2021 9:47 PM, Jiri Olsa wrote:

On Mon, Mar 29, 2021 at 03:00:31PM +0800, Jin Yao wrote:

SNIP

+                          struct parse_events_state *parse_state)
  {
        struct perf_event_attr attr;
        LIST_HEAD(config_terms);
@@ -521,7 +526,7 @@ int parse_events_add_cache(struct list_head *list, int *idx,

i = parse_events__add_cache_hybrid(list, idx, &attr,

                                           config_name ? : name, &config_terms,
-                                          &hybrid);
+                                          &hybrid, parse_state);
        if (hybrid)
                return i;

@@ -1481,7 +1486,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,

        struct perf_pmu *pmu;
        struct evsel *evsel;
        struct parse_events_error *err = parse_state->error;
-       bool use_uncore_alias;
+       bool use_uncore_alias, found = false;
        LIST_HEAD(config_terms);

if (verbose > 1) {

@@ -1530,8 +1535,28 @@ int parse_events_add_pmu(struct parse_events_state 
*parse_state,
                }
        }

- if (!parse_state->fake_pmu && perf_pmu__check_alias(pmu, head_config, &info))

+       if (!parse_state->fake_pmu &&
+           perf_pmu__check_alias(pmu, head_config, &info, &found)) {
                return -EINVAL;
+       }
+

ok, let's not polute surronding functions and make strict check
on what we want in here.. we are after following events:

        cpu_xxx/L1-dcache/
        cpu_xxx/l1-d|/
         ...
right?

Yes, we only focus on the cache events now.

so we are after events with single term in head_config that has name in:

        L1-dcache|l1-d|l1d|L1-data              |
        L1-icache|l1-i|l1i|L1-instruction       |
        LLC|L2                                  |
        dTLB|d-tlb|Data-TLB                     |
        iTLB|i-tlb|Instruction-TLB              |
        branch|branches|bpu|btb|bpc             |
        node

I think that with such direct check the code will be more straight
forward, also let's move it to parse-events-hybrid

Do you suggest we just use string comparison for doing the direct check?

e.g.

if (strstr(term->config, "L1-dcache"))
        ...

Of course, we can define a string array first and use a loop for string 
comparison.

+       if (!parse_state->fake_pmu && head_config && !found &&
+           perf_pmu__is_hybrid(name)) {
+               struct parse_events_term *term;
+               int ret;
+
+               list_for_each_entry(term, head_config, list) {
+                       if (!term->config)
+                               continue;
+
+                       ret = parse_events__with_hybrid_pmu(parse_state,
+                                                           term->config,
+                                                           name, &found,
+                                                           list);

do we need to call the parsing again? could we just call
parse_events__add_cache_hybrid?

jirka

If we do the direct check for cache events, I think we don't need the parsing 
again.

As I mentioned above, we need to define a string array and compare with 
term->config one by one.

I'm OK for this solution. :)

Thanks
Jin Yao

+                       if (found)
+                               return ret;
+               }
+       }

if (verbose > 1) {

                fprintf(stderr, "After aliases, add event pmu '%s' with '",
@@ -1605,6 +1630,15 @@ int parse_events_multi_pmu_add(struct parse_events_state 
*parse_state,
        struct perf_pmu *pmu = NULL;
        int ok = 0;

SNIP