Root/tools/perf/builtin-diff.c

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
19static char const *input_old = "perf.data.old",
20          *input_new = "perf.data";
21static char diff__default_sort_order[] = "dso,symbol";
22static bool force;
23static bool show_displacement;
24
25static 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
33static 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
58static 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
69static 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
89static 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
107static void hists__set_positions(struct hists *self)
108{
109    hists__output_resort(self);
110    hists__resort_entries(self);
111}
112
113static 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
133static 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
143static 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);
166out_delete:
167    for (i = 0; i < 2; ++i)
168        perf_session__delete(session[i]);
169    return ret;
170}
171
172static const char * const diff_usage[] = {
173    "perf diff [<options>] [old_file] [new_file]",
174    NULL,
175};
176
177static 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
203int 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

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