linux/tools/perf/builtin-diff.c
Arnaldo Carvalho de Melo 86a9eee047 perf diff: Introduce tool to show performance difference
I guess it is enough to show some examples:

[root@doppio linux-2.6-tip]# rm -f perf.data*
[root@doppio linux-2.6-tip]# ls -la perf.data*
ls: cannot access perf.data*: No such file or directory
[root@doppio linux-2.6-tip]# perf record -f find / > /dev/null
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.062 MB perf.data (~2699 samples) ]
[root@doppio linux-2.6-tip]# ls -la perf.data*
-rw------- 1 root root 74440 2009-12-14 20:03 perf.data
[root@doppio linux-2.6-tip]# perf record -f find / > /dev/null
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.062 MB perf.data (~2692 samples) ]
[root@doppio linux-2.6-tip]# ls -la perf.data*
-rw------- 1 root root 74280 2009-12-14 20:03 perf.data
-rw------- 1 root root 74440 2009-12-14 20:03 perf.data.old
[root@doppio linux-2.6-tip]# perf diff | head -5
   1        -34994580     /lib64/libc-2.10.1.so   _IO_vfprintf_internal
   2        -15307806         [kernel.kallsyms]   __kmalloc
   3    +1   +3665941     /lib64/libc-2.10.1.so   __GI_memmove
   4    +4  +23508995     /lib64/libc-2.10.1.so   _int_malloc
   5    +7  +38538813         [kernel.kallsyms]   __d_lookup
[root@doppio linux-2.6-tip]# perf diff -p | head -5
   1        +1.00%     /lib64/libc-2.10.1.so   _IO_vfprintf_internal
   2                       [kernel.kallsyms]   __kmalloc
   3    +1             /lib64/libc-2.10.1.so   __GI_memmove
   4    +4             /lib64/libc-2.10.1.so   _int_malloc
   5    +7  -1.00%         [kernel.kallsyms]   __d_lookup
[root@doppio linux-2.6-tip]# perf diff -v | head -5
   1        361449551 326454971 -34994580     /lib64/libc-2.10.1.so   _IO_vfprintf_internal
   2        151009241 135701435 -15307806         [kernel.kallsyms]   __kmalloc
   3    +1  101805328 105471269  +3665941     /lib64/libc-2.10.1.so   __GI_memmove
   4    +4   78041440 101550435 +23508995     /lib64/libc-2.10.1.so   _int_malloc
   5    +7   59536172  98074985 +38538813         [kernel.kallsyms]   __d_lookup
[root@doppio linux-2.6-tip]# perf diff -vp | head -5
   1        9.00% 8.00% +1.00%     /lib64/libc-2.10.1.so   _IO_vfprintf_internal
   2        3.00% 3.00%                [kernel.kallsyms]   __kmalloc
   3    +1  2.00% 2.00%            /lib64/libc-2.10.1.so   __GI_memmove
   4    +4  2.00% 2.00%            /lib64/libc-2.10.1.so   _int_malloc
   5    +7  1.00% 2.00% -1.00%         [kernel.kallsyms]   __d_lookup
[root@doppio linux-2.6-tip]#

This should be enough for diffs where the system is non
volatile, i.e. when one doesn't updates binaries.

For volatile environments, stay tuned for the next perf tool
feature: a buildid cache populated by 'perf record', managed by
'perf buildid-cache' a-la ccache, and used by all the report
tools.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
LKML-Reference: <1260828571-3613-3-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-15 08:50:29 +01:00

289 lines
7.4 KiB
C

/*
* builtin-diff.c
*
* Builtin diff command: Analyze two perf.data input files, look up and read
* DSOs and symbol information, sort them and produce a diff.
*/
#include "builtin.h"
#include "util/debug.h"
#include "util/event.h"
#include "util/hist.h"
#include "util/session.h"
#include "util/sort.h"
#include "util/symbol.h"
#include "util/util.h"
#include <stdlib.h>
static char const *input_old = "perf.data.old",
*input_new = "perf.data";
static int force;
static bool show_percent;
struct symbol_conf symbol_conf;
static int perf_session__add_hist_entry(struct perf_session *self,
struct addr_location *al, u64 count)
{
bool hit;
struct hist_entry *he = __perf_session__add_hist_entry(self, al, NULL,
count, &hit);
if (he == NULL)
return -ENOMEM;
if (hit)
he->count += count;
return 0;
}
static int diff__process_sample_event(event_t *event, struct perf_session *session)
{
struct addr_location al;
struct sample_data data = { .period = 1, };
dump_printf("(IP, %d): %d: %p\n", event->header.misc,
event->ip.pid, (void *)(long)event->ip.ip);
if (event__preprocess_sample(event, session, &al, NULL) < 0) {
pr_warning("problem processing %d event, skipping it.\n",
event->header.type);
return -1;
}
event__parse_sample(event, session->sample_type, &data);
if (al.sym && perf_session__add_hist_entry(session, &al, data.period)) {
pr_warning("problem incrementing symbol count, skipping event\n");
return -1;
}
session->events_stats.total += data.period;
return 0;
}
static struct perf_event_ops event_ops = {
.process_sample_event = diff__process_sample_event,
.process_mmap_event = event__process_mmap,
.process_comm_event = event__process_comm,
.process_exit_event = event__process_task,
.process_fork_event = event__process_task,
.process_lost_event = event__process_lost,
};
static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
struct hist_entry *he)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct hist_entry *iter;
while (*p != NULL) {
int cmp;
parent = *p;
iter = rb_entry(parent, struct hist_entry, rb_node);
cmp = strcmp(he->map->dso->name, iter->map->dso->name);
if (cmp > 0)
p = &(*p)->rb_left;
else if (cmp < 0)
p = &(*p)->rb_right;
else {
cmp = strcmp(he->sym->name, iter->sym->name);
if (cmp > 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
}
rb_link_node(&he->rb_node, parent, p);
rb_insert_color(&he->rb_node, root);
}
static void perf_session__resort_by_name(struct perf_session *self)
{
unsigned long position = 1;
struct rb_root tmp = RB_ROOT;
struct rb_node *next = rb_first(&self->hists);
while (next != NULL) {
struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
next = rb_next(&n->rb_node);
rb_erase(&n->rb_node, &self->hists);
n->position = position++;
perf_session__insert_hist_entry_by_name(&tmp, n);
}
self->hists = tmp;
}
static struct hist_entry *
perf_session__find_hist_entry_by_name(struct perf_session *self,
struct hist_entry *he)
{
struct rb_node *n = self->hists.rb_node;
while (n) {
struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
int cmp = strcmp(he->map->dso->name, iter->map->dso->name);
if (cmp > 0)
n = n->rb_left;
else if (cmp < 0)
n = n->rb_right;
else {
cmp = strcmp(he->sym->name, iter->sym->name);
if (cmp > 0)
n = n->rb_left;
else if (cmp < 0)
n = n->rb_right;
else
return iter;
}
}
return NULL;
}
static void perf_session__match_hists(struct perf_session *old_session,
struct perf_session *new_session)
{
struct rb_node *nd;
perf_session__resort_by_name(old_session);
for (nd = rb_first(&new_session->hists); nd; nd = rb_next(nd)) {
struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
pos->pair = perf_session__find_hist_entry_by_name(old_session, pos);
}
}
static size_t hist_entry__fprintf_matched(struct hist_entry *self,
unsigned long pos,
struct perf_session *session,
struct perf_session *pair_session,
FILE *fp)
{
u64 old_count = 0;
char displacement[16];
size_t printed;
if (self->pair != NULL) {
long pdiff = (long)self->pair->position - (long)pos;
old_count = self->pair->count;
if (pdiff == 0)
goto blank;
snprintf(displacement, sizeof(displacement), "%+4ld", pdiff);
} else {
blank: memset(displacement, ' ', sizeof(displacement));
}
printed = fprintf(fp, "%4lu %5.5s ", pos, displacement);
if (show_percent) {
double old_percent = (old_count * 100) / pair_session->events_stats.total,
new_percent = (self->count * 100) / session->events_stats.total;
double diff = old_percent - new_percent;
if (verbose)
printed += fprintf(fp, " %3.2f%% %3.2f%%", old_percent, new_percent);
if ((u64)diff != 0)
printed += fprintf(fp, " %+4.2F%%", diff);
else
printed += fprintf(fp, " ");
} else {
if (verbose)
printed += fprintf(fp, " %9Lu %9Lu", old_count, self->count);
printed += fprintf(fp, " %+9Ld", (s64)self->count - (s64)old_count);
}
return printed + fprintf(fp, " %25.25s %s\n",
self->map->dso->name, self->sym->name);
}
static size_t perf_session__fprintf_matched_hists(struct perf_session *self,
struct perf_session *pair,
FILE *fp)
{
struct rb_node *nd;
size_t printed = 0;
unsigned long pos = 1;
for (nd = rb_first(&self->hists); nd; nd = rb_next(nd)) {
struct hist_entry *he = rb_entry(nd, struct hist_entry, rb_node);
printed += hist_entry__fprintf_matched(he, pos++, self, pair, fp);
}
return printed;
}
static int __cmd_diff(void)
{
int ret, i;
struct perf_session *session[2];
session[0] = perf_session__new(input_old, O_RDONLY, force, &symbol_conf);
session[1] = perf_session__new(input_new, O_RDONLY, force, &symbol_conf);
if (session[0] == NULL || session[1] == NULL)
return -ENOMEM;
for (i = 0; i < 2; ++i) {
ret = perf_session__process_events(session[i], &event_ops);
if (ret)
goto out_delete;
perf_session__output_resort(session[i], session[i]->events_stats.total);
}
perf_session__match_hists(session[0], session[1]);
perf_session__fprintf_matched_hists(session[1], session[0], stdout);
out_delete:
for (i = 0; i < 2; ++i)
perf_session__delete(session[i]);
return ret;
}
static const char *const diff_usage[] = {
"perf diff [<options>] [old_file] [new_file]",
};
static const struct option options[] = {
OPT_BOOLEAN('v', "verbose", &verbose,
"be more verbose (show symbol address, etc)"),
OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
"dump raw trace in ASCII"),
OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
"load module symbols - WARNING: use only with -k and LIVE kernel"),
OPT_BOOLEAN('p', "percentages", &show_percent,
"Don't shorten the pathnames taking into account the cwd"),
OPT_BOOLEAN('P', "full-paths", &event_ops.full_paths,
"Don't shorten the pathnames taking into account the cwd"),
OPT_END()
};
int cmd_diff(int argc, const char **argv, const char *prefix __used)
{
if (symbol__init(&symbol_conf) < 0)
return -1;
setup_sorting(diff_usage, options);
argc = parse_options(argc, argv, options, diff_usage, 0);
if (argc) {
if (argc > 2)
usage_with_options(diff_usage, options);
if (argc == 2) {
input_old = argv[0];
input_new = argv[1];
} else
input_new = argv[0];
}
setup_pager();
return __cmd_diff();
}