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linux/tools/perf/util/thread.c
David S. Miller 4385d580f2 perf tools: Flush maps on COMM events
Even though we don't register the counters until the child is right about
to exec(), we're still going to get at least a few events while the
fork()'d child is still executing 'perf' and in particular we're going to
get the MMAP events.

We can't distinguish the ones in the newly executed process because the
PID will be the same.

One way to solve this would be to have a PERF_RECORD_EXEC event, and when
this is seen 'perf' can flush it's map cache.  We can't use
PERF_RECORD_COMM since that's generated by other things, not just exec().

Actually, thinking about it some more, using PERF_RECORD_COMM might be a
good enough approximation.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.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>
LKML-Reference: <1267196914-16238-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-26 16:28:45 +01:00

322 lines
7.0 KiB
C

#include "../perf.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "session.h"
#include "thread.h"
#include "util.h"
#include "debug.h"
void map_groups__init(struct map_groups *self)
{
int i;
for (i = 0; i < MAP__NR_TYPES; ++i) {
self->maps[i] = RB_ROOT;
INIT_LIST_HEAD(&self->removed_maps[i]);
}
}
static struct thread *thread__new(pid_t pid)
{
struct thread *self = zalloc(sizeof(*self));
if (self != NULL) {
map_groups__init(&self->mg);
self->pid = pid;
self->comm = malloc(32);
if (self->comm)
snprintf(self->comm, 32, ":%d", self->pid);
}
return self;
}
static void map_groups__flush(struct map_groups *self)
{
int type;
for (type = 0; type < MAP__NR_TYPES; type++) {
struct rb_root *root = &self->maps[type];
struct rb_node *next = rb_first(root);
while (next) {
struct map *pos = rb_entry(next, struct map, rb_node);
next = rb_next(&pos->rb_node);
rb_erase(&pos->rb_node, root);
/*
* We may have references to this map, for
* instance in some hist_entry instances, so
* just move them to a separate list.
*/
list_add_tail(&pos->node, &self->removed_maps[pos->type]);
}
}
}
int thread__set_comm(struct thread *self, const char *comm)
{
int err;
if (self->comm)
free(self->comm);
self->comm = strdup(comm);
err = self->comm == NULL ? -ENOMEM : 0;
if (!err) {
self->comm_set = true;
map_groups__flush(&self->mg);
}
return err;
}
int thread__comm_len(struct thread *self)
{
if (!self->comm_len) {
if (!self->comm)
return 0;
self->comm_len = strlen(self->comm);
}
return self->comm_len;
}
static size_t __map_groups__fprintf_maps(struct map_groups *self,
enum map_type type, FILE *fp)
{
size_t printed = fprintf(fp, "%s:\n", map_type__name[type]);
struct rb_node *nd;
for (nd = rb_first(&self->maps[type]); nd; nd = rb_next(nd)) {
struct map *pos = rb_entry(nd, struct map, rb_node);
printed += fprintf(fp, "Map:");
printed += map__fprintf(pos, fp);
if (verbose > 1) {
printed += dso__fprintf(pos->dso, type, fp);
printed += fprintf(fp, "--\n");
}
}
return printed;
}
size_t map_groups__fprintf_maps(struct map_groups *self, FILE *fp)
{
size_t printed = 0, i;
for (i = 0; i < MAP__NR_TYPES; ++i)
printed += __map_groups__fprintf_maps(self, i, fp);
return printed;
}
static size_t __map_groups__fprintf_removed_maps(struct map_groups *self,
enum map_type type, FILE *fp)
{
struct map *pos;
size_t printed = 0;
list_for_each_entry(pos, &self->removed_maps[type], node) {
printed += fprintf(fp, "Map:");
printed += map__fprintf(pos, fp);
if (verbose > 1) {
printed += dso__fprintf(pos->dso, type, fp);
printed += fprintf(fp, "--\n");
}
}
return printed;
}
static size_t map_groups__fprintf_removed_maps(struct map_groups *self, FILE *fp)
{
size_t printed = 0, i;
for (i = 0; i < MAP__NR_TYPES; ++i)
printed += __map_groups__fprintf_removed_maps(self, i, fp);
return printed;
}
static size_t map_groups__fprintf(struct map_groups *self, FILE *fp)
{
size_t printed = map_groups__fprintf_maps(self, fp);
printed += fprintf(fp, "Removed maps:\n");
return printed + map_groups__fprintf_removed_maps(self, fp);
}
static size_t thread__fprintf(struct thread *self, FILE *fp)
{
return fprintf(fp, "Thread %d %s\n", self->pid, self->comm) +
map_groups__fprintf(&self->mg, fp);
}
struct thread *perf_session__findnew(struct perf_session *self, pid_t pid)
{
struct rb_node **p = &self->threads.rb_node;
struct rb_node *parent = NULL;
struct thread *th;
/*
* Font-end cache - PID lookups come in blocks,
* so most of the time we dont have to look up
* the full rbtree:
*/
if (self->last_match && self->last_match->pid == pid)
return self->last_match;
while (*p != NULL) {
parent = *p;
th = rb_entry(parent, struct thread, rb_node);
if (th->pid == pid) {
self->last_match = th;
return th;
}
if (pid < th->pid)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
th = thread__new(pid);
if (th != NULL) {
rb_link_node(&th->rb_node, parent, p);
rb_insert_color(&th->rb_node, &self->threads);
self->last_match = th;
}
return th;
}
static void map_groups__remove_overlappings(struct map_groups *self,
struct map *map)
{
struct rb_root *root = &self->maps[map->type];
struct rb_node *next = rb_first(root);
while (next) {
struct map *pos = rb_entry(next, struct map, rb_node);
next = rb_next(&pos->rb_node);
if (!map__overlap(pos, map))
continue;
if (verbose >= 2) {
fputs("overlapping maps:\n", stderr);
map__fprintf(map, stderr);
map__fprintf(pos, stderr);
}
rb_erase(&pos->rb_node, root);
/*
* We may have references to this map, for instance in some
* hist_entry instances, so just move them to a separate
* list.
*/
list_add_tail(&pos->node, &self->removed_maps[map->type]);
}
}
void maps__insert(struct rb_root *maps, struct map *map)
{
struct rb_node **p = &maps->rb_node;
struct rb_node *parent = NULL;
const u64 ip = map->start;
struct map *m;
while (*p != NULL) {
parent = *p;
m = rb_entry(parent, struct map, rb_node);
if (ip < m->start)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&map->rb_node, parent, p);
rb_insert_color(&map->rb_node, maps);
}
struct map *maps__find(struct rb_root *maps, u64 ip)
{
struct rb_node **p = &maps->rb_node;
struct rb_node *parent = NULL;
struct map *m;
while (*p != NULL) {
parent = *p;
m = rb_entry(parent, struct map, rb_node);
if (ip < m->start)
p = &(*p)->rb_left;
else if (ip > m->end)
p = &(*p)->rb_right;
else
return m;
}
return NULL;
}
void thread__insert_map(struct thread *self, struct map *map)
{
map_groups__remove_overlappings(&self->mg, map);
map_groups__insert(&self->mg, map);
}
/*
* XXX This should not really _copy_ te maps, but refcount them.
*/
static int map_groups__clone(struct map_groups *self,
struct map_groups *parent, enum map_type type)
{
struct rb_node *nd;
for (nd = rb_first(&parent->maps[type]); nd; nd = rb_next(nd)) {
struct map *map = rb_entry(nd, struct map, rb_node);
struct map *new = map__clone(map);
if (new == NULL)
return -ENOMEM;
map_groups__insert(self, new);
}
return 0;
}
int thread__fork(struct thread *self, struct thread *parent)
{
int i;
if (parent->comm_set) {
if (self->comm)
free(self->comm);
self->comm = strdup(parent->comm);
if (!self->comm)
return -ENOMEM;
self->comm_set = true;
}
for (i = 0; i < MAP__NR_TYPES; ++i)
if (map_groups__clone(&self->mg, &parent->mg, i) < 0)
return -ENOMEM;
return 0;
}
size_t perf_session__fprintf(struct perf_session *self, FILE *fp)
{
size_t ret = 0;
struct rb_node *nd;
for (nd = rb_first(&self->threads); nd; nd = rb_next(nd)) {
struct thread *pos = rb_entry(nd, struct thread, rb_node);
ret += thread__fprintf(pos, fp);
}
return ret;
}
struct symbol *map_groups__find_symbol(struct map_groups *self,
enum map_type type, u64 addr,
symbol_filter_t filter)
{
struct map *map = map_groups__find(self, type, addr);
if (map != NULL)
return map__find_symbol(map, map->map_ip(map, addr), filter);
return NULL;
}