perf_counter tools: Resolve symbols in callchains

This patch resolves the names, when possible, of each ip
present in the callchains while using the -c option with perf
report.

Example:

5.40%  [k] __d_lookup
             5.37%
                perf_callchain
                perf_counter_overflow
                intel_pmu_handle_irq
                perf_counter_nmi_handler
                notifier_call_chain
                atomic_notifier_call_chain
                notify_die
                do_nmi
                nmi
                do_lookup
                __link_path_walk
                path_walk
                do_path_lookup
                user_path_at
                sys_faccessat
                sys_access
                system_call_fastpath
                0x7fb609846f77

             0.01%
                perf_callchain
                perf_counter_overflow
                intel_pmu_handle_irq
                perf_counter_nmi_handler
                notifier_call_chain
                atomic_notifier_call_chain
                notify_die
                do_nmi
                nmi
                do_lookup
                __link_path_walk
                path_walk
                do_path_lookup
                user_path_at
                sys_faccessat

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1246419315-9968-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 90 insertions, 50 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 3f5d8ea05ff0..197793051fa5 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -794,8 +794,15 @@ callchain__fprintf(FILE *fp, struct callchain_node *self, u64 total_samples)
         ret += callchain__fprintf(fp, self->parent, total_samples);
 
 
-        list_for_each_entry(chain, &self->val, list)
-                ret += fprintf(fp, "                %p\n", (void *)chain->ip);
+        list_for_each_entry(chain, &self->val, list) {
+                if (chain->ip >= PERF_CONTEXT_MAX)
+                        continue;
+                if (chain->sym)
+                        ret += fprintf(fp, "                %s\n", chain->sym->name);
+                else
+                        ret += fprintf(fp, "                %p\n",
+                                        (void *)chain->ip);
+        }
 
         return ret;
 }
@@ -930,6 +937,55 @@ static int call__match(struct symbol *sym)
         return 0;
 }
 
+static struct symbol **
+resolve_callchain(struct thread *thread, struct map *map,
+                    struct ip_callchain *chain, struct hist_entry *entry)
+{
+        int i;
+        struct symbol **syms;
+        u64 context = PERF_CONTEXT_MAX;
+
+        if (callchain) {
+                syms = calloc(chain->nr, sizeof(*syms));
+                if (!syms) {
+                        fprintf(stderr, "Can't allocate memory for symbols\n");
+                        exit(-1);
+                }
+        }
+
+        for (i = 0; i < chain->nr; i++) {
+                u64 ip = chain->ips[i];
+                struct dso *dso = NULL;
+                struct symbol *sym;
+
+                if (ip >= PERF_CONTEXT_MAX) {
+                        context = ip;
+                        continue;
+                }
+
+                switch (context) {
+                case PERF_CONTEXT_KERNEL:
+                        dso = kernel_dso;
+                        break;
+                default:
+                        break;
+                }
+
+                sym = resolve_symbol(thread, NULL, &dso, &ip);
+
+                if (sym) {
+                        if (sort__has_parent && call__match(sym) &&
+                            !entry->parent)
+                                entry->parent = sym;
+                        if (!callchain)
+                                break;
+                        syms[i] = sym;
+                }
+        }
+
+        return syms;
+}
+
 /*
  * collect histogram counts
  */
@@ -942,6 +998,7 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
         struct rb_node **p = &hist.rb_node;
         struct rb_node *parent = NULL;
         struct hist_entry *he;
+        struct symbol **syms = NULL;
         struct hist_entry entry = {
                 .thread = thread,
                 .map    = map,
@@ -955,39 +1012,11 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
         };
         int cmp;
 
-        if (sort__has_parent && chain) {
-                u64 context = PERF_CONTEXT_MAX;
-                int i;
-
-                for (i = 0; i < chain->nr; i++) {
-                        u64 ip = chain->ips[i];
-                        struct dso *dso = NULL;
-                        struct symbol *sym;
-
-                        if (ip >= PERF_CONTEXT_MAX) {
-                                context = ip;
-                                continue;
-                        }
-
-                        switch (context) {
                         case PERF_CONTEXT_HV:
                                 dso = hypervisor_dso;
                                 break;
-                        case PERF_CONTEXT_KERNEL:
-                                dso = kernel_dso;
-                                break;
-                        default:
-                                break;
-                        }
-
-                        sym = resolve_symbol(thread, NULL, &dso, &ip);
-
-                        if (sym && call__match(sym)) {
-                                entry.parent = sym;
-                                break;
-                        }
-                }
-        }
+        if ((sort__has_parent || callchain) && chain)
+                syms = resolve_callchain(thread, map, chain, &entry);
 
         while (*p != NULL) {
                 parent = *p;
@@ -997,8 +1026,10 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
 
                 if (!cmp) {
                         he->count += count;
-                        if (callchain)
-                                append_chain(&he->callchain, chain);
+                        if (callchain) {
+                                append_chain(&he->callchain, chain, syms);
+                                free(syms);
+                        }
                         return 0;
                 }
 
@@ -1014,7 +1045,8 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
         *he = entry;
         if (callchain) {
                 callchain_init(&he->callchain);
-                append_chain(&he->callchain, chain);
+                append_chain(&he->callchain, chain, syms);
+                free(syms);
         }
         rb_link_node(&he->rb_node, parent, p);
         rb_insert_color(&he->rb_node, &hist);
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index bbf7813fefe0..6568cb198ba6 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -67,7 +67,8 @@ static struct callchain_node *create_child(struct callchain_node *parent)
 }
 
 static void
-fill_node(struct callchain_node *node, struct ip_callchain *chain, int start)
+fill_node(struct callchain_node *node, struct ip_callchain *chain, int start,
+          struct symbol **syms)
 {
         int i;
 
@@ -80,24 +81,26 @@ fill_node(struct callchain_node *node, struct ip_callchain *chain, int start)
                         return;
                 }
                 call->ip = chain->ips[i];
+                call->sym = syms[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)
+static void add_child(struct callchain_node *parent, struct ip_callchain *chain,
+                      struct symbol **syms)
 {
         struct callchain_node *new;
 
         new = create_child(parent);
-        fill_node(new, chain, parent->val_nr);
+        fill_node(new, chain, parent->val_nr, syms);
 
         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_list *to_split, int idx, struct symbol **syms)
 {
         struct callchain_node *new;
 
@@ -109,21 +112,22 @@ split_add_child(struct callchain_node *parent, struct ip_callchain *chain,
         parent->val_nr = idx;
 
         /* create the new one */
-        add_child(parent, chain);
+        add_child(parent, chain, syms);
 }
 
 static int
 __append_chain(struct callchain_node *root, struct ip_callchain *chain,
-                int start);
+               int start, struct symbol **syms);
 
 static int
-__append_chain_children(struct callchain_node *root, struct ip_callchain *chain)
+__append_chain_children(struct callchain_node *root, struct ip_callchain *chain,
+                        struct symbol **syms)
 {
         struct callchain_node *rnode;
 
         /* lookup in childrens */
         list_for_each_entry(rnode, &root->children, brothers) {
-                int ret = __append_chain(rnode, chain, root->val_nr);
+                int ret = __append_chain(rnode, chain, root->val_nr, syms);
                 if (!ret)
                         return 0;
         }
@@ -132,7 +136,7 @@ __append_chain_children(struct callchain_node *root, struct ip_callchain *chain)
 
 static int
 __append_chain(struct callchain_node *root, struct ip_callchain *chain,
-                int start)
+               int start, struct symbol **syms)
 {
         struct callchain_list *cnode;
         int i = start;
@@ -154,7 +158,7 @@ __append_chain(struct callchain_node *root, struct ip_callchain *chain,
 
         /* 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);
+                split_add_child(root, chain, cnode, i, syms);
                 return 0;
         }
 
@@ -164,11 +168,12 @@ __append_chain(struct callchain_node *root, struct ip_callchain *chain,
                 return 0;
         }
 
-        return __append_chain_children(root, chain);
+        return __append_chain_children(root, chain, syms);
 }
 
-void append_chain(struct callchain_node *root, struct ip_callchain *chain)
+void append_chain(struct callchain_node *root, struct ip_callchain *chain,
+                  struct symbol **syms)
 {
-        if (__append_chain_children(root, chain) == -1)
-                add_child(root, chain);
+        if (__append_chain_children(root, chain, syms) == -1)
+                add_child(root, chain, syms);
 }
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index fa1cd2f71fd3..c942daa712e6 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -4,6 +4,7 @@
 #include "../perf.h"
 #include "list.h"
 #include "rbtree.h"
+#include "symbol.h"
 
 
 struct callchain_node {
@@ -18,6 +19,7 @@ struct callchain_node {
 
 struct callchain_list {
         unsigned long           ip;
+        struct symbol           *sym;
         struct list_head        list;
 };
 
@@ -28,6 +30,7 @@ static inline void callchain_init(struct callchain_node *node)
         INIT_LIST_HEAD(&node->val);
 }
 
-void append_chain(struct callchain_node *root, struct ip_callchain *chain);
+void append_chain(struct callchain_node *root, struct ip_callchain *chain,
+                  struct symbol **syms);
 void sort_chain_to_rbtree(struct rb_root *rb_root, struct callchain_node *node);
 #endif