perf tools: Don't use parent comm if not set at fork time

As the parent comm then is worthless, confusing users about the
thread where the sample really happened, leading to think that
the sample happened in the parent, not where it really happened,
in the children of a thread for which a PERF_RECORD_COMM event
was not received.

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: <1266627727-19715-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Arnaldo Carvalho de Melo 2010-02-19 23:02:07 -02:00 committed by Ingo Molnar
parent 10fe12ef63
commit faa5c5c36e
2 changed files with 13 additions and 6 deletions

View File

@ -36,7 +36,10 @@ int thread__set_comm(struct thread *self, const char *comm)
if (self->comm)
free(self->comm);
self->comm = strdup(comm);
return self->comm ? 0 : -ENOMEM;
if (self->comm == NULL)
return -ENOMEM;
self->comm_set = true;
return 0;
}
int thread__comm_len(struct thread *self)
@ -255,11 +258,14 @@ int thread__fork(struct thread *self, struct thread *parent)
{
int i;
if (self->comm)
free(self->comm);
self->comm = strdup(parent->comm);
if (!self->comm)
return -ENOMEM;
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)

View File

@ -15,6 +15,7 @@ struct thread {
struct map_groups mg;
pid_t pid;
char shortname[3];
bool comm_set;
char *comm;
int comm_len;
};