perf tools: Fix thread comm resolution in perf sched
This reverts commit 9a92b479b2f088ee2d3194243f4c8e59b1b8c9c2 ("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>
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 25b91e7..6b00529 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -638,7 +638,7 @@
{
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 @@
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 @@
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 @@
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 @@
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;
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 8bd5ca2..3b56aeb 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -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 @@
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 @@
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);
@@ -96,19 +91,6 @@
}
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)
{
struct thread *thread = threads__findnew(0, threads, last_match);
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 75bc843..845d9b6 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -18,9 +18,6 @@
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);