Re: [PATCH v1 05/14] perf util: Calculate the sum of all streams hits

["Jin, Yao" <yao.jin@linux.intel.com>]

On 3/10/2020 11:14 PM, Arnaldo Carvalho de Melo wrote:
> Em Tue, Mar 10, 2020 at 03:02:36PM +0800, Jin Yao escreveu:
>> We have used callchain_node->hit to measure the hot level of one
>> stream. This patch calculates the sum of hits of all streams.
>>
>> Then in next patch, we can use following formula to report hot
>> percent for one stream.
>>
>> hot percent = callchain_node->hit / sum of all hits
>>
>> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
>> ---
>>   tools/perf/util/callchain.c | 35 +++++++++++++++++++++++++++++++++++
>>   tools/perf/util/callchain.h |  1 +
>>   2 files changed, 36 insertions(+)
>>
>> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
>> index a9dd91268b00..040995405664 100644
>> --- a/tools/perf/util/callchain.c
>> +++ b/tools/perf/util/callchain.c
>> @@ -1685,6 +1685,39 @@ static void update_hot_streams(struct hist_entry *he,
>>   	}
>>   }
>>   
>> +static u64 count_callchain_hits(struct hist_entry *he)
>> +{
>> +	struct rb_root *root = &he->sorted_chain;
>> +	struct rb_node *rb_node = rb_first(root);
>> +	struct callchain_node *node;
>> +	u64 chain_hits = 0;
>> +
>> +	while (rb_node) {
>> +		node = rb_entry(rb_node, struct callchain_node, rb_node);
>> +		chain_hits += node->hit;
>> +		rb_node = rb_next(rb_node);
>> +	}
>> +
>> +	return chain_hits;
>> +}
>> +
>> +static u64 total_callchain_hits(struct hists *hists)
>> +{
>> +	struct rb_node *next;
>> +	u64 chain_hits = 0;
>> +
>> +	next = rb_first_cached(&hists->entries);
> 
> Try to combine the variable decl line with its initial assignment,
> saving one line, i.e.:
> 
> +static u64 total_callchain_hits(struct hists *hists)
> +{
> +	struct rb_node *next = rb_first_cached(&hists->entries);
> +	u64 chain_hits = 0;
> +

Yes, combining to one line is easy for reading. I will update the code.

>> +	while (next) {
>> +		struct hist_entry *he;
>> +
>> +		he = rb_entry(next, struct hist_entry, rb_node);
> 
> Ditto:
> 
> +		struct hist_entry *he = rb_entry(next, struct hist_entry, rb_node);
> 

Got it.

Thanks
Jin Yao

>> +		chain_hits += count_callchain_hits(he);
>> +		next = rb_next(&he->rb_node);
>> +	}
>> +
>> +	return chain_hits;
>> +}
>> +
>>   static void get_hot_streams(struct hists *hists,
>>   			    struct callchain_streams *s)
>>   {
>> @@ -1698,6 +1731,8 @@ static void get_hot_streams(struct hists *hists,
>>   		update_hot_streams(he, s);
>>   		next = rb_next(&he->rb_node);
>>   	}
>> +
>> +	s->chain_hits = total_callchain_hits(hists);
>>   }
>>   
>>   struct callchain_streams *callchain_evsel_streams_create(struct evlist *evlist,
>> diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
>> index c996ab4fb108..3c0e0b45656b 100644
>> --- a/tools/perf/util/callchain.h
>> +++ b/tools/perf/util/callchain.h
>> @@ -173,6 +173,7 @@ struct callchain_streams {
>>   	int			nr_streams_max;
>>   	int			nr_streams;
>>   	int			evsel_idx;
>> +	u64			chain_hits;
>>   };
>>   
>>   extern __thread struct callchain_cursor callchain_cursor;
>> -- 
>> 2.17.1
>>
>