callchain.h

Go to the documentation of this file.

#ifndef __PERF_CALLCHAIN_H
#define __PERF_CALLCHAIN_H

#include "../perf.h"
#include <linux/list.h>
#include <linux/rbtree.h>
#include "event.h"
#include "symbol.h"

enum chain_mode {
    CHAIN_NONE,
    CHAIN_FLAT,
    CHAIN_GRAPH_ABS,
    CHAIN_GRAPH_REL
};

enum chain_order {
    ORDER_CALLER,
    ORDER_CALLEE
};

struct callchain_node {
    struct callchain_node   *parent;
    struct list_head    siblings;
    struct list_head    children;
    struct list_head    val;
    struct rb_node      rb_node; /* to sort nodes in an rbtree */
    struct rb_root      rb_root; /* sorted tree of children */
    unsigned int        val_nr;
    u64         hit;
    u64         children_hit;
};

struct callchain_root {
    u64         max_depth;
    struct callchain_node   node;
};

struct callchain_param;

typedef void (*sort_chain_func_t)(struct rb_root *, struct callchain_root *,
                 u64, struct callchain_param *);

struct callchain_param {
    enum chain_mode     mode;
    u32         print_limit;
    double          min_percent;
    sort_chain_func_t   sort;
    enum chain_order    order;
};

struct callchain_list {
    u64         ip;
    struct map_symbol   ms;
    struct list_head    list;
};

/*
 * A callchain cursor is a single linked list that
 * let one feed a callchain progressively.
 * It keeps persistent allocated entries to minimize
 * allocations.
 */
struct callchain_cursor_node {
    u64             ip;
    struct map          *map;
    struct symbol           *sym;
    struct callchain_cursor_node    *next;
};

struct callchain_cursor {
    u64             nr;
    struct callchain_cursor_node    *first;
    struct callchain_cursor_node    **last;
    u64             pos;
    struct callchain_cursor_node    *curr;
};

extern __thread struct callchain_cursor callchain_cursor;

static inline void callchain_init(struct callchain_root *root)
{
    INIT_LIST_HEAD(&root->node.siblings);
    INIT_LIST_HEAD(&root->node.children);
    INIT_LIST_HEAD(&root->node.val);

    root->node.parent = NULL;
    root->node.hit = 0;
    root->node.children_hit = 0;
    root->max_depth = 0;
}

static inline u64 callchain_cumul_hits(struct callchain_node *node)
{
    return node->hit + node->children_hit;
}

int callchain_register_param(struct callchain_param *param);
int callchain_append(struct callchain_root *root,
             struct callchain_cursor *cursor,
             u64 period);

int callchain_merge(struct callchain_cursor *cursor,
            struct callchain_root *dst, struct callchain_root *src);

struct ip_callchain;
union perf_event;

bool ip_callchain__valid(struct ip_callchain *chain,
             const union perf_event *event);
/*
 * Initialize a cursor before adding entries inside, but keep
 * the previously allocated entries as a cache.
 */
static inline void callchain_cursor_reset(struct callchain_cursor *cursor)
{
    cursor->nr = 0;
    cursor->last = &cursor->first;
}

int callchain_cursor_append(struct callchain_cursor *cursor, u64 ip,
                struct map *map, struct symbol *sym);

/* Close a cursor writing session. Initialize for the reader */
static inline void callchain_cursor_commit(struct callchain_cursor *cursor)
{
    cursor->curr = cursor->first;
    cursor->pos = 0;
}

/* Cursor reading iteration helpers */
static inline struct callchain_cursor_node *
callchain_cursor_current(struct callchain_cursor *cursor)
{
    if (cursor->pos == cursor->nr)
        return NULL;

    return cursor->curr;
}

static inline void callchain_cursor_advance(struct callchain_cursor *cursor)
{
    cursor->curr = cursor->curr->next;
    cursor->pos++;
}
#endif  /* __PERF_CALLCHAIN_H */