1 /*
2 * builtin-diff.c
3 *
4 * Builtin diff command: Analyze two perf.data input files, look up and read
5 * DSOs and symbol information, sort them and produce a diff.
6 */
7 #include "builtin.h"
8
9 #include "util/debug.h"
10 #include "util/event.h"
11 #include "util/hist.h"
12 #include "util/session.h"
13 #include "util/sort.h"
14 #include "util/symbol.h"
15 #include "util/util.h"
16
17 #include <stdlib.h>
18
19 static char const *input_old = "perf.data.old",
20 *input_new = "perf.data";
21 static char diff__default_sort_order[] = "dso,symbol";
22 static bool force;
23 static bool show_displacement;
24
hists__add_entry(struct hists * self,struct addr_location * al,u64 period)25 static int hists__add_entry(struct hists *self,
26 struct addr_location *al, u64 period)
27 {
28 if (__hists__add_entry(self, al, NULL, period) != NULL)
29 return 0;
30 return -ENOMEM;
31 }
32
diff__process_sample_event(union perf_event * event,struct perf_sample * sample,struct perf_evsel * evsel __used,struct perf_session * session)33 static int diff__process_sample_event(union perf_event *event,
34 struct perf_sample *sample,
35 struct perf_evsel *evsel __used,
36 struct perf_session *session)
37 {
38 struct addr_location al;
39
40 if (perf_event__preprocess_sample(event, session, &al, sample, NULL) < 0) {
41 pr_warning("problem processing %d event, skipping it.\n",
42 event->header.type);
43 return -1;
44 }
45
46 if (al.filtered || al.sym == NULL)
47 return 0;
48
49 if (hists__add_entry(&session->hists, &al, sample->period)) {
50 pr_warning("problem incrementing symbol period, skipping event\n");
51 return -1;
52 }
53
54 session->hists.stats.total_period += sample->period;
55 return 0;
56 }
57
58 static struct perf_event_ops event_ops = {
59 .sample = diff__process_sample_event,
60 .mmap = perf_event__process_mmap,
61 .comm = perf_event__process_comm,
62 .exit = perf_event__process_task,
63 .fork = perf_event__process_task,
64 .lost = perf_event__process_lost,
65 .ordered_samples = true,
66 .ordering_requires_timestamps = true,
67 };
68
perf_session__insert_hist_entry_by_name(struct rb_root * root,struct hist_entry * he)69 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
70 struct hist_entry *he)
71 {
72 struct rb_node **p = &root->rb_node;
73 struct rb_node *parent = NULL;
74 struct hist_entry *iter;
75
76 while (*p != NULL) {
77 parent = *p;
78 iter = rb_entry(parent, struct hist_entry, rb_node);
79 if (hist_entry__cmp(he, iter) < 0)
80 p = &(*p)->rb_left;
81 else
82 p = &(*p)->rb_right;
83 }
84
85 rb_link_node(&he->rb_node, parent, p);
86 rb_insert_color(&he->rb_node, root);
87 }
88
hists__resort_entries(struct hists * self)89 static void hists__resort_entries(struct hists *self)
90 {
91 unsigned long position = 1;
92 struct rb_root tmp = RB_ROOT;
93 struct rb_node *next = rb_first(&self->entries);
94
95 while (next != NULL) {
96 struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
97
98 next = rb_next(&n->rb_node);
99 rb_erase(&n->rb_node, &self->entries);
100 n->position = position++;
101 perf_session__insert_hist_entry_by_name(&tmp, n);
102 }
103
104 self->entries = tmp;
105 }
106
hists__set_positions(struct hists * self)107 static void hists__set_positions(struct hists *self)
108 {
109 hists__output_resort(self);
110 hists__resort_entries(self);
111 }
112
hists__find_entry(struct hists * self,struct hist_entry * he)113 static struct hist_entry *hists__find_entry(struct hists *self,
114 struct hist_entry *he)
115 {
116 struct rb_node *n = self->entries.rb_node;
117
118 while (n) {
119 struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
120 int64_t cmp = hist_entry__cmp(he, iter);
121
122 if (cmp < 0)
123 n = n->rb_left;
124 else if (cmp > 0)
125 n = n->rb_right;
126 else
127 return iter;
128 }
129
130 return NULL;
131 }
132
hists__match(struct hists * older,struct hists * newer)133 static void hists__match(struct hists *older, struct hists *newer)
134 {
135 struct rb_node *nd;
136
137 for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
138 struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
139 pos->pair = hists__find_entry(older, pos);
140 }
141 }
142
__cmd_diff(void)143 static int __cmd_diff(void)
144 {
145 int ret, i;
146 struct perf_session *session[2];
147
148 session[0] = perf_session__new(input_old, O_RDONLY, force, false, &event_ops);
149 session[1] = perf_session__new(input_new, O_RDONLY, force, false, &event_ops);
150 if (session[0] == NULL || session[1] == NULL)
151 return -ENOMEM;
152
153 for (i = 0; i < 2; ++i) {
154 ret = perf_session__process_events(session[i], &event_ops);
155 if (ret)
156 goto out_delete;
157 }
158
159 hists__output_resort(&session[1]->hists);
160 if (show_displacement)
161 hists__set_positions(&session[0]->hists);
162
163 hists__match(&session[0]->hists, &session[1]->hists);
164 hists__fprintf(&session[1]->hists, &session[0]->hists,
165 show_displacement, stdout);
166 out_delete:
167 for (i = 0; i < 2; ++i)
168 perf_session__delete(session[i]);
169 return ret;
170 }
171
172 static const char * const diff_usage[] = {
173 "perf diff [<options>] [old_file] [new_file]",
174 NULL,
175 };
176
177 static const struct option options[] = {
178 OPT_INCR('v', "verbose", &verbose,
179 "be more verbose (show symbol address, etc)"),
180 OPT_BOOLEAN('M', "displacement", &show_displacement,
181 "Show position displacement relative to baseline"),
182 OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
183 "dump raw trace in ASCII"),
184 OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
185 OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
186 "load module symbols - WARNING: use only with -k and LIVE kernel"),
187 OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
188 "only consider symbols in these dsos"),
189 OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
190 "only consider symbols in these comms"),
191 OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
192 "only consider these symbols"),
193 OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
194 "sort by key(s): pid, comm, dso, symbol, parent"),
195 OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
196 "separator for columns, no spaces will be added between "
197 "columns '.' is reserved."),
198 OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
199 "Look for files with symbols relative to this directory"),
200 OPT_END()
201 };
202
cmd_diff(int argc,const char ** argv,const char * prefix __used)203 int cmd_diff(int argc, const char **argv, const char *prefix __used)
204 {
205 sort_order = diff__default_sort_order;
206 argc = parse_options(argc, argv, options, diff_usage, 0);
207 if (argc) {
208 if (argc > 2)
209 usage_with_options(diff_usage, options);
210 if (argc == 2) {
211 input_old = argv[0];
212 input_new = argv[1];
213 } else
214 input_new = argv[0];
215 } else if (symbol_conf.default_guest_vmlinux_name ||
216 symbol_conf.default_guest_kallsyms) {
217 input_old = "perf.data.host";
218 input_new = "perf.data.guest";
219 }
220
221 symbol_conf.exclude_other = false;
222 if (symbol__init() < 0)
223 return -1;
224
225 setup_sorting(diff_usage, options);
226 setup_pager();
227
228 sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
229 sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
230 sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
231
232 return __cmd_diff();
233 }
234