linux/tools/perf/util/hist.c

#include "hist.h"

struct rb_root hist;
int callchain;

struct callchain_param	callchain_param = {
	.mode	= CHAIN_GRAPH_REL,
	.min_percent = 0.5
};

/*
 * histogram, sorted on item, collects counts
 */

struct hist_entry *__hist_entry__add(struct addr_location *al,
				     struct symbol *sym_parent,
				     u64 count, bool *hit)
{
	struct rb_node **p = &hist.rb_node;
	struct rb_node *parent = NULL;
	struct hist_entry *he;
	struct hist_entry entry = {
		.thread	= al->thread,
		.map	= al->map,
		.sym	= al->sym,
		.ip	= al->addr,
		.level	= al->level,
		.count	= count,
		.parent = sym_parent,
	};
	int cmp;

	while (*p != NULL) {
		parent = *p;
		he = rb_entry(parent, struct hist_entry, rb_node);

		cmp = hist_entry__cmp(&entry, he);

		if (!cmp) {
			*hit = true;
			return he;
		}

		if (cmp < 0)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	he = malloc(sizeof(*he));
	if (!he)
		return NULL;
	*he = entry;
	rb_link_node(&he->rb_node, parent, p);
	rb_insert_color(&he->rb_node, &hist);
	*hit = false;
	return he;
}

int64_t
hist_entry__cmp(struct hist_entry *left, struct hist_entry *right)
{
	struct sort_entry *se;
	int64_t cmp = 0;

	list_for_each_entry(se, &hist_entry__sort_list, list) {
		cmp = se->cmp(left, right);
		if (cmp)
			break;
	}

	return cmp;
}

int64_t
hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
{
	struct sort_entry *se;
	int64_t cmp = 0;

	list_for_each_entry(se, &hist_entry__sort_list, list) {
		int64_t (*f)(struct hist_entry *, struct hist_entry *);

		f = se->collapse ?: se->cmp;

		cmp = f(left, right);
		if (cmp)
			break;
	}

	return cmp;
}

void hist_entry__free(struct hist_entry *he)
{
	free(he);
}

/*
 * collapse the histogram
 */

static void collapse__insert_entry(struct rb_root *root, struct hist_entry *he)
{
	struct rb_node **p = &root->rb_node;
	struct rb_node *parent = NULL;
	struct hist_entry *iter;
	int64_t cmp;

	while (*p != NULL) {
		parent = *p;
		iter = rb_entry(parent, struct hist_entry, rb_node);

		cmp = hist_entry__collapse(iter, he);

		if (!cmp) {
			iter->count += he->count;
			hist_entry__free(he);
			return;
		}

		if (cmp < 0)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	rb_link_node(&he->rb_node, parent, p);
	rb_insert_color(&he->rb_node, root);
}

void collapse__resort(void)
{
	struct rb_root tmp;
	struct rb_node *next;
	struct hist_entry *n;

	if (!sort__need_collapse)
		return;

	tmp = RB_ROOT;
	next = rb_first(&hist);

	while (next) {
		n = rb_entry(next, struct hist_entry, rb_node);
		next = rb_next(&n->rb_node);

		rb_erase(&n->rb_node, &hist);
		collapse__insert_entry(&tmp, n);
	}

	hist = tmp;
}

/*
 * reverse the map, sort on count.
 */

static void output__insert_entry(struct rb_root *root, struct hist_entry *he,
				 u64 min_callchain_hits)
{
	struct rb_node **p = &root->rb_node;
	struct rb_node *parent = NULL;
	struct hist_entry *iter;

	if (callchain)
		callchain_param.sort(&he->sorted_chain, &he->callchain,
				      min_callchain_hits, &callchain_param);

	while (*p != NULL) {
		parent = *p;
		iter = rb_entry(parent, struct hist_entry, rb_node);

		if (he->count > iter->count)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	rb_link_node(&he->rb_node, parent, p);
	rb_insert_color(&he->rb_node, root);
}

void output__resort(u64 total_samples)
{
	struct rb_root tmp;
	struct rb_node *next;
	struct hist_entry *n;
	u64 min_callchain_hits;

	min_callchain_hits =
		total_samples * (callchain_param.min_percent / 100);

	tmp = RB_ROOT;
	next = rb_first(&hist);

	while (next) {
		n = rb_entry(next, struct hist_entry, rb_node);
		next = rb_next(&n->rb_node);

		rb_erase(&n->rb_node, &hist);
		output__insert_entry(&tmp, n, min_callchain_hits);
	}

	hist = tmp;
}