linux/tools/perf/builtin-diff.c
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   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