xref: /openbmc/linux/tools/perf/builtin-diff.c (revision 95e9fd10)
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/evsel.h"
13 #include "util/session.h"
14 #include "util/tool.h"
15 #include "util/sort.h"
16 #include "util/symbol.h"
17 #include "util/util.h"
18 
19 #include <stdlib.h>
20 
21 static char const *input_old = "perf.data.old",
22 		  *input_new = "perf.data";
23 static char	  diff__default_sort_order[] = "dso,symbol";
24 static bool  force;
25 static bool show_displacement;
26 
27 struct perf_diff {
28 	struct perf_tool tool;
29 	struct perf_session *session;
30 };
31 
32 static int hists__add_entry(struct hists *self,
33 			    struct addr_location *al, u64 period)
34 {
35 	if (__hists__add_entry(self, al, NULL, period) != NULL)
36 		return 0;
37 	return -ENOMEM;
38 }
39 
40 static int diff__process_sample_event(struct perf_tool *tool,
41 				      union perf_event *event,
42 				      struct perf_sample *sample,
43 				      struct perf_evsel *evsel __used,
44 				      struct machine *machine)
45 {
46 	struct perf_diff *_diff = container_of(tool, struct perf_diff, tool);
47 	struct perf_session *session = _diff->session;
48 	struct addr_location al;
49 
50 	if (perf_event__preprocess_sample(event, machine, &al, sample, NULL) < 0) {
51 		pr_warning("problem processing %d event, skipping it.\n",
52 			   event->header.type);
53 		return -1;
54 	}
55 
56 	if (al.filtered || al.sym == NULL)
57 		return 0;
58 
59 	if (hists__add_entry(&session->hists, &al, sample->period)) {
60 		pr_warning("problem incrementing symbol period, skipping event\n");
61 		return -1;
62 	}
63 
64 	session->hists.stats.total_period += sample->period;
65 	return 0;
66 }
67 
68 static struct perf_diff diff = {
69 	.tool = {
70 		.sample	= diff__process_sample_event,
71 		.mmap	= perf_event__process_mmap,
72 		.comm	= perf_event__process_comm,
73 		.exit	= perf_event__process_task,
74 		.fork	= perf_event__process_task,
75 		.lost	= perf_event__process_lost,
76 		.ordered_samples = true,
77 		.ordering_requires_timestamps = true,
78 	},
79 };
80 
81 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
82 						    struct hist_entry *he)
83 {
84 	struct rb_node **p = &root->rb_node;
85 	struct rb_node *parent = NULL;
86 	struct hist_entry *iter;
87 
88 	while (*p != NULL) {
89 		parent = *p;
90 		iter = rb_entry(parent, struct hist_entry, rb_node);
91 		if (hist_entry__cmp(he, iter) < 0)
92 			p = &(*p)->rb_left;
93 		else
94 			p = &(*p)->rb_right;
95 	}
96 
97 	rb_link_node(&he->rb_node, parent, p);
98 	rb_insert_color(&he->rb_node, root);
99 }
100 
101 static void hists__resort_entries(struct hists *self)
102 {
103 	unsigned long position = 1;
104 	struct rb_root tmp = RB_ROOT;
105 	struct rb_node *next = rb_first(&self->entries);
106 
107 	while (next != NULL) {
108 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
109 
110 		next = rb_next(&n->rb_node);
111 		rb_erase(&n->rb_node, &self->entries);
112 		n->position = position++;
113 		perf_session__insert_hist_entry_by_name(&tmp, n);
114 	}
115 
116 	self->entries = tmp;
117 }
118 
119 static struct hist_entry *hists__find_entry(struct hists *self,
120 					    struct hist_entry *he)
121 {
122 	struct rb_node *n = self->entries.rb_node;
123 
124 	while (n) {
125 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
126 		int64_t cmp = hist_entry__cmp(he, iter);
127 
128 		if (cmp < 0)
129 			n = n->rb_left;
130 		else if (cmp > 0)
131 			n = n->rb_right;
132 		else
133 			return iter;
134 	}
135 
136 	return NULL;
137 }
138 
139 static void hists__match(struct hists *older, struct hists *newer)
140 {
141 	struct rb_node *nd;
142 
143 	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
144 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
145 		pos->pair = hists__find_entry(older, pos);
146 	}
147 }
148 
149 static int __cmd_diff(void)
150 {
151 	int ret, i;
152 #define older (session[0])
153 #define newer (session[1])
154 	struct perf_session *session[2];
155 
156 	older = perf_session__new(input_old, O_RDONLY, force, false,
157 				  &diff.tool);
158 	newer = perf_session__new(input_new, O_RDONLY, force, false,
159 				  &diff.tool);
160 	if (session[0] == NULL || session[1] == NULL)
161 		return -ENOMEM;
162 
163 	for (i = 0; i < 2; ++i) {
164 		diff.session = session[i];
165 		ret = perf_session__process_events(session[i], &diff.tool);
166 		if (ret)
167 			goto out_delete;
168 		hists__output_resort(&session[i]->hists);
169 	}
170 
171 	if (show_displacement)
172 		hists__resort_entries(&older->hists);
173 
174 	hists__match(&older->hists, &newer->hists);
175 	hists__fprintf(&newer->hists, &older->hists,
176 		       show_displacement, true, 0, 0, stdout);
177 out_delete:
178 	for (i = 0; i < 2; ++i)
179 		perf_session__delete(session[i]);
180 	return ret;
181 #undef older
182 #undef newer
183 }
184 
185 static const char * const diff_usage[] = {
186 	"perf diff [<options>] [old_file] [new_file]",
187 	NULL,
188 };
189 
190 static const struct option options[] = {
191 	OPT_INCR('v', "verbose", &verbose,
192 		    "be more verbose (show symbol address, etc)"),
193 	OPT_BOOLEAN('M', "displacement", &show_displacement,
194 		    "Show position displacement relative to baseline"),
195 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
196 		    "dump raw trace in ASCII"),
197 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
198 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
199 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
200 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
201 		   "only consider symbols in these dsos"),
202 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
203 		   "only consider symbols in these comms"),
204 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
205 		   "only consider these symbols"),
206 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
207 		   "sort by key(s): pid, comm, dso, symbol, parent"),
208 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
209 		   "separator for columns, no spaces will be added between "
210 		   "columns '.' is reserved."),
211 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
212 		    "Look for files with symbols relative to this directory"),
213 	OPT_END()
214 };
215 
216 int cmd_diff(int argc, const char **argv, const char *prefix __used)
217 {
218 	sort_order = diff__default_sort_order;
219 	argc = parse_options(argc, argv, options, diff_usage, 0);
220 	if (argc) {
221 		if (argc > 2)
222 			usage_with_options(diff_usage, options);
223 		if (argc == 2) {
224 			input_old = argv[0];
225 			input_new = argv[1];
226 		} else
227 			input_new = argv[0];
228 	} else if (symbol_conf.default_guest_vmlinux_name ||
229 		   symbol_conf.default_guest_kallsyms) {
230 		input_old = "perf.data.host";
231 		input_new = "perf.data.guest";
232 	}
233 
234 	symbol_conf.exclude_other = false;
235 	if (symbol__init() < 0)
236 		return -1;
237 
238 	setup_sorting(diff_usage, options);
239 	setup_pager();
240 
241 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
242 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
243 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
244 
245 	return __cmd_diff();
246 }
247