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/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
  21static char const *input_old = "perf.data.old",
  22                  *input_new = "perf.data";
  23static char       diff__default_sort_order[] = "dso,symbol";
  24static bool  force;
  25static bool show_displacement;
  26
  27struct perf_diff {
  28        struct perf_tool tool;
  29        struct perf_session *session;
  30};
  31
  32static 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
  40static 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
  68static 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
  81static 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
 101static 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
 119static 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
 139static 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
 149static 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);
 177out_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
 185static const char * const diff_usage[] = {
 186        "perf diff [<options>] [old_file] [new_file]",
 187        NULL,
 188};
 189
 190static 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
 216int 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
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