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Commit 8cb76d99 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

perf_counter tools: Prepare a small callchain framework 



We plan to display the callchains depending on some user-configurable
parameters.

To gather the callchains stats from the recorded stream in a fast way,
this patch introduces an ad hoc radix tree adapted for callchains and also
a rbtree to sort these callchains once we have gathered every events
from the stream.

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1246026481-8314-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 3928ddbe

tools/perf/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -329,6 +329,7 @@ LIB_OBJS += util/symbol.o 
LIB_OBJS += util/color.o

LIB_OBJS += util/pager.o

LIB_OBJS += util/header.o

LIB_OBJS += util/callchain.o



BUILTIN_OBJS += builtin-annotate.o

BUILTIN_OBJS += builtin-help.o

tools/perf/builtin-report.c

+0 −5
Original line number Diff line number Diff line
@@ -62,11 +62,6 @@ struct ip_event { 
	unsigned char __more_data[];

};



struct ip_callchain {

	u64 nr;

	u64 ips[0];

};



struct mmap_event {

	struct perf_event_header header;

	u32 pid, tid;

tools/perf/perf.h

+5 −0
Original line number Diff line number Diff line
@@ -66,4 +66,9 @@ sys_perf_counter_open(struct perf_counter_attr *attr, 
#define MAX_COUNTERS			256

#define MAX_NR_CPUS			256



struct ip_callchain {

	u64 nr;

	u64 ips[0];

};



#endif

tools/perf/util/callchain.c

0 → 100644
+174 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2009, Frederic Weisbecker <fweisbec@gmail.com>

 *

 * Handle the callchains from the stream in an ad-hoc radix tree and then

 * sort them in an rbtree.

 *

 */



#include <stdlib.h>

#include <stdio.h>

#include <stdbool.h>

#include <errno.h>



#include "callchain.h"





static void rb_insert_callchain(struct rb_root *root, struct callchain_node *chain)

{

	struct rb_node **p = &root->rb_node;

	struct rb_node *parent = NULL;

	struct callchain_node *rnode;



	while (*p) {

		parent = *p;

		rnode = rb_entry(parent, struct callchain_node, rb_node);



		if (rnode->hit < chain->hit)

			p = &(*p)->rb_left;

		else

			p = &(*p)->rb_right;

	}



	rb_link_node(&chain->rb_node, parent, p);

	rb_insert_color(&chain->rb_node, root);

}



/*

 * Once we get every callchains from the stream, we can now

 * sort them by hit

 */

void sort_chain_to_rbtree(struct rb_root *rb_root, struct callchain_node *node)

{

	struct callchain_node *child;



	list_for_each_entry(child, &node->children, brothers)

		sort_chain_to_rbtree(rb_root, child);



	if (node->hit)

		rb_insert_callchain(rb_root, node);

}



static struct callchain_node *create_child(struct callchain_node *parent)

{

	struct callchain_node *new;



	new = malloc(sizeof(*new));

	if (!new) {

		perror("not enough memory to create child for code path tree");

		return NULL;

	}

	new->parent = parent;

	INIT_LIST_HEAD(&new->children);

	INIT_LIST_HEAD(&new->val);

	list_add_tail(&new->brothers, &parent->children);



	return new;

}



static void

fill_node(struct callchain_node *node, struct ip_callchain *chain, int start)

{

	int i;



	for (i = start; i < chain->nr; i++) {

		struct callchain_list *call;



		call = malloc(sizeof(*chain));

		if (!call) {

			perror("not enough memory for the code path tree");

			return;

		}

		call->ip = chain->ips[i];

		list_add_tail(&call->list, &node->val);

	}

	node->val_nr = i - start;

}



static void add_child(struct callchain_node *parent, struct ip_callchain *chain)

{

	struct callchain_node *new;



	new = create_child(parent);

	fill_node(new, chain, parent->val_nr);



	new->hit = 1;

}



static void

split_add_child(struct callchain_node *parent, struct ip_callchain *chain,

		struct callchain_list *to_split, int idx)

{

	struct callchain_node *new;



	/* split */

	new = create_child(parent);

	list_move_tail(&to_split->list, &new->val);

	new->hit = parent->hit;

	parent->hit = 0;

	parent->val_nr = idx;



	/* create the new one */

	add_child(parent, chain);

}



static int

__append_chain(struct callchain_node *root, struct ip_callchain *chain,

		int start);



static int

__append_chain_children(struct callchain_node *root, struct ip_callchain *chain)

{

	struct callchain_node *rnode;



	/* lookup in childrens */

	list_for_each_entry(rnode, &root->children, brothers) {

		int ret = __append_chain(rnode, chain, root->val_nr);

		if (!ret)

			return 0;

	}

	return -1;

}



static int

__append_chain(struct callchain_node *root, struct ip_callchain *chain,

		int start)

{

	struct callchain_list *cnode;

	int i = start;

	bool found = false;



	/* lookup in the current node */

	list_for_each_entry(cnode, &root->val, list) {

		if (cnode->ip != chain->ips[i++])

			break;

		if (!found)

			found = true;

		if (i == chain->nr)

			break;

	}



	/* matches not, relay on the parent */

	if (!found)

		return -1;



	/* we match only a part of the node. Split it and add the new chain */

	if (i < root->val_nr) {

		split_add_child(root, chain, cnode, i);

		return 0;

	}



	/* we match 100% of the path, increment the hit */

	if (i == root->val_nr) {

		root->hit++;

		return 0;

	}



	return __append_chain_children(root, chain);

}



void append_chain(struct callchain_node *root, struct ip_callchain *chain)

{

	if (__append_chain_children(root, chain) == -1)

		add_child(root, chain);

}

tools/perf/util/callchain.h

0 → 100644
+33 −0
Original line number Diff line number Diff line 
#ifndef __PERF_CALLCHAIN_H

#define __PERF_CALLCHAIN_H



#include "../perf.h"

#include "list.h"

#include "rbtree.h"





struct callchain_node {

	struct callchain_node	*parent;

	struct list_head	brothers;

	struct list_head 	children;

	struct list_head 	val;

	struct rb_node		rb_node;

	int			val_nr;

	int			hit;

};



struct callchain_list {

	unsigned long		ip;

	struct list_head	list;

};



static inline void callchain_init(struct callchain_node *node)

{

	INIT_LIST_HEAD(&node->brothers);

	INIT_LIST_HEAD(&node->children);

	INIT_LIST_HEAD(&node->val);

}



void append_chain(struct callchain_node *root, struct ip_callchain *chain);

void sort_chain_to_rbtree(struct rb_root *rb_root, struct callchain_node *node);

#endif