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![Frederic Weisbecker](/assets/img/avatar_default.png)
If a new callchain branch doesn't match a single entry of the node that it is given against comparison in append_chain(), then the cursor is expected to be at the same position as it was before the comparison loop. As such, there is no need to restore the cursor position on exit in case of non matching branches. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1389713836-13375-4-git-send-email-fweisbec@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
553 lines
13 KiB
C
553 lines
13 KiB
C
/*
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* Copyright (C) 2009-2011, Frederic Weisbecker <fweisbec@gmail.com>
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*
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* Handle the callchains from the stream in an ad-hoc radix tree and then
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* sort them in an rbtree.
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*
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* Using a radix for code path provides a fast retrieval and factorizes
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* memory use. Also that lets us use the paths in a hierarchical graph view.
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*
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdbool.h>
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#include <errno.h>
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#include <math.h>
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#include "asm/bug.h"
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#include "hist.h"
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#include "util.h"
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#include "sort.h"
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#include "machine.h"
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#include "callchain.h"
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__thread struct callchain_cursor callchain_cursor;
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static void
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rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
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enum chain_mode mode)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct callchain_node *rnode;
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u64 chain_cumul = callchain_cumul_hits(chain);
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while (*p) {
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u64 rnode_cumul;
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parent = *p;
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rnode = rb_entry(parent, struct callchain_node, rb_node);
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rnode_cumul = callchain_cumul_hits(rnode);
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switch (mode) {
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case CHAIN_FLAT:
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if (rnode->hit < chain->hit)
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p = &(*p)->rb_left;
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else
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p = &(*p)->rb_right;
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break;
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case CHAIN_GRAPH_ABS: /* Falldown */
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case CHAIN_GRAPH_REL:
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if (rnode_cumul < chain_cumul)
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p = &(*p)->rb_left;
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else
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p = &(*p)->rb_right;
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break;
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case CHAIN_NONE:
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default:
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break;
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}
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}
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rb_link_node(&chain->rb_node, parent, p);
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rb_insert_color(&chain->rb_node, root);
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}
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static void
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__sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
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u64 min_hit)
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{
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struct rb_node *n;
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struct callchain_node *child;
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n = rb_first(&node->rb_root_in);
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while (n) {
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child = rb_entry(n, struct callchain_node, rb_node_in);
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n = rb_next(n);
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__sort_chain_flat(rb_root, child, min_hit);
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}
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if (node->hit && node->hit >= min_hit)
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rb_insert_callchain(rb_root, node, CHAIN_FLAT);
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}
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/*
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* Once we get every callchains from the stream, we can now
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* sort them by hit
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*/
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static void
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sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
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u64 min_hit, struct callchain_param *param __maybe_unused)
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{
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__sort_chain_flat(rb_root, &root->node, min_hit);
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}
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static void __sort_chain_graph_abs(struct callchain_node *node,
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u64 min_hit)
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{
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struct rb_node *n;
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struct callchain_node *child;
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node->rb_root = RB_ROOT;
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n = rb_first(&node->rb_root_in);
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while (n) {
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child = rb_entry(n, struct callchain_node, rb_node_in);
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n = rb_next(n);
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__sort_chain_graph_abs(child, min_hit);
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if (callchain_cumul_hits(child) >= min_hit)
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rb_insert_callchain(&node->rb_root, child,
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CHAIN_GRAPH_ABS);
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}
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}
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static void
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sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
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u64 min_hit, struct callchain_param *param __maybe_unused)
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{
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__sort_chain_graph_abs(&chain_root->node, min_hit);
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rb_root->rb_node = chain_root->node.rb_root.rb_node;
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}
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static void __sort_chain_graph_rel(struct callchain_node *node,
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double min_percent)
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{
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struct rb_node *n;
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struct callchain_node *child;
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u64 min_hit;
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node->rb_root = RB_ROOT;
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min_hit = ceil(node->children_hit * min_percent);
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n = rb_first(&node->rb_root_in);
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while (n) {
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child = rb_entry(n, struct callchain_node, rb_node_in);
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n = rb_next(n);
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__sort_chain_graph_rel(child, min_percent);
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if (callchain_cumul_hits(child) >= min_hit)
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rb_insert_callchain(&node->rb_root, child,
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CHAIN_GRAPH_REL);
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}
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}
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static void
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sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
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u64 min_hit __maybe_unused, struct callchain_param *param)
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{
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__sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
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rb_root->rb_node = chain_root->node.rb_root.rb_node;
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}
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int callchain_register_param(struct callchain_param *param)
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{
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switch (param->mode) {
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case CHAIN_GRAPH_ABS:
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param->sort = sort_chain_graph_abs;
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break;
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case CHAIN_GRAPH_REL:
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param->sort = sort_chain_graph_rel;
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break;
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case CHAIN_FLAT:
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param->sort = sort_chain_flat;
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break;
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case CHAIN_NONE:
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default:
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return -1;
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}
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return 0;
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}
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/*
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* Create a child for a parent. If inherit_children, then the new child
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* will become the new parent of it's parent children
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*/
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static struct callchain_node *
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create_child(struct callchain_node *parent, bool inherit_children)
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{
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struct callchain_node *new;
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new = zalloc(sizeof(*new));
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if (!new) {
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perror("not enough memory to create child for code path tree");
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return NULL;
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}
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new->parent = parent;
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INIT_LIST_HEAD(&new->val);
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if (inherit_children) {
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struct rb_node *n;
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struct callchain_node *child;
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new->rb_root_in = parent->rb_root_in;
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parent->rb_root_in = RB_ROOT;
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n = rb_first(&new->rb_root_in);
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while (n) {
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child = rb_entry(n, struct callchain_node, rb_node_in);
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child->parent = new;
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n = rb_next(n);
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}
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/* make it the first child */
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rb_link_node(&new->rb_node_in, NULL, &parent->rb_root_in.rb_node);
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rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
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}
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return new;
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}
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/*
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* Fill the node with callchain values
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*/
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static void
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fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
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{
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struct callchain_cursor_node *cursor_node;
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node->val_nr = cursor->nr - cursor->pos;
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if (!node->val_nr)
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pr_warning("Warning: empty node in callchain tree\n");
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cursor_node = callchain_cursor_current(cursor);
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while (cursor_node) {
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struct callchain_list *call;
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call = zalloc(sizeof(*call));
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if (!call) {
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perror("not enough memory for the code path tree");
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return;
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}
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call->ip = cursor_node->ip;
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call->ms.sym = cursor_node->sym;
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call->ms.map = cursor_node->map;
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list_add_tail(&call->list, &node->val);
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callchain_cursor_advance(cursor);
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cursor_node = callchain_cursor_current(cursor);
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}
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}
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static struct callchain_node *
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add_child(struct callchain_node *parent,
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struct callchain_cursor *cursor,
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u64 period)
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{
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struct callchain_node *new;
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new = create_child(parent, false);
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fill_node(new, cursor);
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new->children_hit = 0;
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new->hit = period;
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return new;
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}
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static s64 match_chain(struct callchain_cursor_node *node,
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struct callchain_list *cnode)
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{
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struct symbol *sym = node->sym;
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if (cnode->ms.sym && sym &&
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callchain_param.key == CCKEY_FUNCTION)
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return cnode->ms.sym->start - sym->start;
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else
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return cnode->ip - node->ip;
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}
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/*
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* Split the parent in two parts (a new child is created) and
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* give a part of its callchain to the created child.
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* Then create another child to host the given callchain of new branch
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*/
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static void
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split_add_child(struct callchain_node *parent,
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struct callchain_cursor *cursor,
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struct callchain_list *to_split,
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u64 idx_parents, u64 idx_local, u64 period)
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{
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struct callchain_node *new;
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struct list_head *old_tail;
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unsigned int idx_total = idx_parents + idx_local;
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/* split */
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new = create_child(parent, true);
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/* split the callchain and move a part to the new child */
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old_tail = parent->val.prev;
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list_del_range(&to_split->list, old_tail);
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new->val.next = &to_split->list;
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new->val.prev = old_tail;
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to_split->list.prev = &new->val;
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old_tail->next = &new->val;
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/* split the hits */
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new->hit = parent->hit;
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new->children_hit = parent->children_hit;
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parent->children_hit = callchain_cumul_hits(new);
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new->val_nr = parent->val_nr - idx_local;
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parent->val_nr = idx_local;
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/* create a new child for the new branch if any */
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if (idx_total < cursor->nr) {
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struct callchain_node *first;
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struct callchain_list *cnode;
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struct callchain_cursor_node *node;
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struct rb_node *p, **pp;
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parent->hit = 0;
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parent->children_hit += period;
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node = callchain_cursor_current(cursor);
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new = add_child(parent, cursor, period);
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/*
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* This is second child since we moved parent's children
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* to new (first) child above.
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*/
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p = parent->rb_root_in.rb_node;
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first = rb_entry(p, struct callchain_node, rb_node_in);
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cnode = list_first_entry(&first->val, struct callchain_list,
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list);
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if (match_chain(node, cnode) < 0)
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pp = &p->rb_left;
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else
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pp = &p->rb_right;
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rb_link_node(&new->rb_node_in, p, pp);
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rb_insert_color(&new->rb_node_in, &parent->rb_root_in);
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} else {
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parent->hit = period;
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}
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}
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static int
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append_chain(struct callchain_node *root,
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struct callchain_cursor *cursor,
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u64 period);
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static void
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append_chain_children(struct callchain_node *root,
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struct callchain_cursor *cursor,
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u64 period)
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{
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struct callchain_node *rnode;
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struct callchain_cursor_node *node;
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struct rb_node **p = &root->rb_root_in.rb_node;
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struct rb_node *parent = NULL;
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node = callchain_cursor_current(cursor);
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if (!node)
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return;
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/* lookup in childrens */
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while (*p) {
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s64 ret;
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parent = *p;
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rnode = rb_entry(parent, struct callchain_node, rb_node_in);
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/* If at least first entry matches, rely to children */
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ret = append_chain(rnode, cursor, period);
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if (ret == 0)
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goto inc_children_hit;
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if (ret < 0)
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p = &parent->rb_left;
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else
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p = &parent->rb_right;
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}
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/* nothing in children, add to the current node */
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rnode = add_child(root, cursor, period);
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rb_link_node(&rnode->rb_node_in, parent, p);
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rb_insert_color(&rnode->rb_node_in, &root->rb_root_in);
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inc_children_hit:
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root->children_hit += period;
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}
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static int
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append_chain(struct callchain_node *root,
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struct callchain_cursor *cursor,
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u64 period)
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{
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struct callchain_list *cnode;
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u64 start = cursor->pos;
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bool found = false;
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u64 matches;
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int cmp = 0;
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/*
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* Lookup in the current node
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* If we have a symbol, then compare the start to match
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* anywhere inside a function, unless function
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* mode is disabled.
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*/
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list_for_each_entry(cnode, &root->val, list) {
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struct callchain_cursor_node *node;
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node = callchain_cursor_current(cursor);
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if (!node)
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break;
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cmp = match_chain(node, cnode);
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if (cmp)
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break;
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found = true;
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callchain_cursor_advance(cursor);
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}
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/* matches not, relay no the parent */
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if (!found) {
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WARN_ONCE(!cmp, "Chain comparison error\n");
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return cmp;
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}
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matches = cursor->pos - start;
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/* we match only a part of the node. Split it and add the new chain */
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if (matches < root->val_nr) {
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split_add_child(root, cursor, cnode, start, matches, period);
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return 0;
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}
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/* we match 100% of the path, increment the hit */
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if (matches == root->val_nr && cursor->pos == cursor->nr) {
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root->hit += period;
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return 0;
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}
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/* We match the node and still have a part remaining */
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append_chain_children(root, cursor, period);
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return 0;
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}
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int callchain_append(struct callchain_root *root,
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struct callchain_cursor *cursor,
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u64 period)
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{
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if (!cursor->nr)
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return 0;
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callchain_cursor_commit(cursor);
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append_chain_children(&root->node, cursor, period);
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if (cursor->nr > root->max_depth)
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root->max_depth = cursor->nr;
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return 0;
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}
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static int
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merge_chain_branch(struct callchain_cursor *cursor,
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struct callchain_node *dst, struct callchain_node *src)
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{
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struct callchain_cursor_node **old_last = cursor->last;
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struct callchain_node *child;
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struct callchain_list *list, *next_list;
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struct rb_node *n;
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int old_pos = cursor->nr;
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int err = 0;
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list_for_each_entry_safe(list, next_list, &src->val, list) {
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callchain_cursor_append(cursor, list->ip,
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list->ms.map, list->ms.sym);
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list_del(&list->list);
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free(list);
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}
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if (src->hit) {
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callchain_cursor_commit(cursor);
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append_chain_children(dst, cursor, src->hit);
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}
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n = rb_first(&src->rb_root_in);
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while (n) {
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child = container_of(n, struct callchain_node, rb_node_in);
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n = rb_next(n);
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rb_erase(&child->rb_node_in, &src->rb_root_in);
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err = merge_chain_branch(cursor, dst, child);
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if (err)
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break;
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free(child);
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}
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cursor->nr = old_pos;
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cursor->last = old_last;
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return err;
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}
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int callchain_merge(struct callchain_cursor *cursor,
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struct callchain_root *dst, struct callchain_root *src)
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{
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return merge_chain_branch(cursor, &dst->node, &src->node);
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}
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int callchain_cursor_append(struct callchain_cursor *cursor,
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u64 ip, struct map *map, struct symbol *sym)
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{
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struct callchain_cursor_node *node = *cursor->last;
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if (!node) {
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node = calloc(1, sizeof(*node));
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if (!node)
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return -ENOMEM;
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*cursor->last = node;
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}
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node->ip = ip;
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node->map = map;
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node->sym = sym;
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cursor->nr++;
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cursor->last = &node->next;
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return 0;
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}
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int sample__resolve_callchain(struct perf_sample *sample, struct symbol **parent,
|
|
struct perf_evsel *evsel, struct addr_location *al,
|
|
int max_stack)
|
|
{
|
|
if (sample->callchain == NULL)
|
|
return 0;
|
|
|
|
if (symbol_conf.use_callchain || sort__has_parent) {
|
|
return machine__resolve_callchain(al->machine, evsel, al->thread,
|
|
sample, parent, al, max_stack);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int hist_entry__append_callchain(struct hist_entry *he, struct perf_sample *sample)
|
|
{
|
|
if (!symbol_conf.use_callchain)
|
|
return 0;
|
|
return callchain_append(he->callchain, &callchain_cursor, sample->period);
|
|
}
|