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

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Message-ID: <20200310151405.GH15931@kernel.org>
Date:   Tue, 10 Mar 2020 12:14:05 -0300
From:   Arnaldo Carvalho de Melo <arnaldo.melo@...il.com>
To:     Jin Yao <yao.jin@...ux.intel.com>
Cc:     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 v1 05/14] perf util: Calculate the sum of all streams hits

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@...ux.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;
+
> +	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);

> +		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
> 

-- 

- Arnaldo