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perf tools: Fix thread comm resolution in perf sched 

This reverts commit 9a92b479b2 ("perf
tools: Improve thread comm resolution in perf sched") and fixes the
real bug.

The bug was elsewhere:

We are failing to resolve thread names in perf sched because the
table of threads we are building, on top of comm events, has a per
process granularity. But perf sched, unlike the other perf tools,
needs a per thread granularity as we are profiling every tasks
individually.

So fix it by building our threads table using the tid instead of
the pid as the thread identifier.

v2: Revert the previous fix - it is not really needed

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1255028657-11158-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker 2009-10-08 21:04:17 +02:00 committed by Ingo Molnar
parent 2e538c4a18
commit 97ea1a7fa6
3 changed files with 13 additions and 68 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
tools/perf/builtin-sched.c
View File

@ -638,7 +638,7 @@ process_comm_event(event_t *event, unsigned long offset, unsigned long head)
{
struct thread *thread;
thread = threads__findnew(event->comm.pid, &threads, &last_match);
thread = threads__findnew(event->comm.tid, &threads, &last_match);
dump_printf("%p [%p]: perf_event_comm: %s:%d\n",
(void *)(offset + head),
@ -1034,36 +1034,6 @@ add_sched_in_event(struct work_atoms *atoms, u64 timestamp)
atoms->nb_atoms++;
}
static struct thread *
threads__findnew_from_ctx(u32 pid, struct trace_switch_event *switch_event)
{
struct thread *th;
th = threads__findnew_nocomm(pid, &threads, &last_match);
if (th->comm)
return th;
if (pid == switch_event->prev_pid)
thread__set_comm(th, switch_event->prev_comm);
else
thread__set_comm(th, switch_event->next_comm);
return th;
}
static struct thread *
threads__findnew_from_wakeup(struct trace_wakeup_event *wakeup_event)
{
struct thread *th;
th = threads__findnew_nocomm(wakeup_event->pid, &threads, &last_match);
if (th->comm)
return th;
thread__set_comm(th, wakeup_event->comm);
return th;
}
static void
latency_switch_event(struct trace_switch_event *switch_event,
struct event *event __used,
@ -1089,10 +1059,8 @@ latency_switch_event(struct trace_switch_event *switch_event,
die("hm, delta: %Ld < 0 ?\n", delta);
sched_out = threads__findnew_from_ctx(switch_event->prev_pid,
switch_event);
sched_in = threads__findnew_from_ctx(switch_event->next_pid,
switch_event);
sched_out = threads__findnew(switch_event->prev_pid, &threads, &last_match);
sched_in = threads__findnew(switch_event->next_pid, &threads, &last_match);
out_events = thread_atoms_search(&atom_root, sched_out, &cmp_pid);
if (!out_events) {
@ -1158,7 +1126,7 @@ latency_wakeup_event(struct trace_wakeup_event *wakeup_event,
if (!wakeup_event->success)
return;
wakee = threads__findnew_from_wakeup(wakeup_event);
wakee = threads__findnew(wakeup_event->pid, &threads, &last_match);
atoms = thread_atoms_search(&atom_root, wakee, &cmp_pid);
if (!atoms) {
thread_atoms_insert(wakee);
@ -1418,10 +1386,8 @@ map_switch_event(struct trace_switch_event *switch_event,
die("hm, delta: %Ld < 0 ?\n", delta);
sched_out = threads__findnew_from_ctx(switch_event->prev_pid,
switch_event);
sched_in = threads__findnew_from_ctx(switch_event->next_pid,
switch_event);
sched_out = threads__findnew(switch_event->prev_pid, &threads, &last_match);
sched_in = threads__findnew(switch_event->next_pid, &threads, &last_match);
curr_thread[this_cpu] = sched_in;

32
tools/perf/util/thread.c
View File

@ -6,17 +6,15 @@
#include "util.h"
#include "debug.h"
static struct thread *thread__new(pid_t pid, int set_comm)
static struct thread *thread__new(pid_t pid)
{
struct thread *self = calloc(1, sizeof(*self));
if (self != NULL) {
self->pid = pid;
if (set_comm) {
self->comm = malloc(32);
if (self->comm)
snprintf(self->comm, 32, ":%d", self->pid);
}
self->comm = malloc(32);
if (self->comm)
snprintf(self->comm, 32, ":%d", self->pid);
self->maps = RB_ROOT;
INIT_LIST_HEAD(&self->removed_maps);
}
@ -52,10 +50,8 @@ static size_t thread__fprintf(struct thread *self, FILE *fp)
return ret;
}
static struct thread *
__threads__findnew(pid_t pid, struct rb_root *threads,
struct thread **last_match,
int set_comm)
struct thread *
threads__findnew(pid_t pid, struct rb_root *threads, struct thread **last_match)
{
struct rb_node **p = &threads->rb_node;
struct rb_node *parent = NULL;
@ -84,8 +80,7 @@ __threads__findnew(pid_t pid, struct rb_root *threads,
p = &(*p)->rb_right;
}
th = thread__new(pid, set_comm);
th = thread__new(pid);
if (th != NULL) {
rb_link_node(&th->rb_node, parent, p);
rb_insert_color(&th->rb_node, threads);
@ -95,19 +90,6 @@ __threads__findnew(pid_t pid, struct rb_root *threads,
return th;
}
struct thread *
threads__findnew(pid_t pid, struct rb_root *threads, struct thread **last_match)
{
return __threads__findnew(pid, threads, last_match, 1);
}
struct thread *
threads__findnew_nocomm(pid_t pid, struct rb_root *threads,
struct thread **last_match)
{
return __threads__findnew(pid, threads, last_match, 0);
}
struct thread *
register_idle_thread(struct rb_root *threads, struct thread **last_match)
{

3
tools/perf/util/thread.h
View File

@ -18,9 +18,6 @@ int thread__set_comm(struct thread *self, const char *comm);
struct thread *
threads__findnew(pid_t pid, struct rb_root *threads, struct thread **last_match);
struct thread *
threads__findnew_nocomm(pid_t pid, struct rb_root *threads,
struct thread **last_match);
struct thread *
register_idle_thread(struct rb_root *threads, struct thread **last_match);
void thread__insert_map(struct thread *self, struct map *map);
int thread__fork(struct thread *self, struct thread *parent);