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perf tools: Fix ppid for synthesized fork events

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363b785f38 added synthesized fork events and set a thread's parent id to
itself. Since we are already processing /proc/<pid>/status the ppid can
be determined properly. Make it so.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Mario <jmario@redhat.com>
Link: http://lkml.kernel.org/r/1427747758-18510-2-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
David Ahern 2015-03-30 14:35:58 -06:00 committed by Arnaldo Carvalho de Melo
parent 5aa0b030e8
commit ca6c41c59b
1 changed files with 50 additions and 33 deletions
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83
tools/perf/util/event.c
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@ -51,29 +51,32 @@ static struct perf_sample synth_sample = {
/*
* Assumes that the first 4095 bytes of /proc/pid/stat contains
* the comm and tgid.
* the comm, tgid and ppid.
*/
static pid_t perf_event__get_comm_tgid(pid_t pid, char *comm, size_t len)
static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len,
pid_t *tgid, pid_t *ppid)
{
char filename[PATH_MAX];
char bf[4096];
int fd;
size_t size = 0, n;
pid_t tgid = -1;
char *nl, *name, *tgids;
char *nl, *name, *tgids, *ppids;
*tgid = -1;
*ppid = -1;
snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
fd = open(filename, O_RDONLY);
if (fd < 0) {
pr_debug("couldn't open %s\n", filename);
return 0;
return -1;
}
n = read(fd, bf, sizeof(bf) - 1);
close(fd);
if (n <= 0) {
pr_warning("Couldn't get COMM and tgid for pid %d\n",
pr_warning("Couldn't get COMM, tigd and ppid for pid %d\n",
pid);
return -1;
}
@ -81,6 +84,7 @@ static pid_t perf_event__get_comm_tgid(pid_t pid, char *comm, size_t len)
name = strstr(bf, "Name:");
tgids = strstr(bf, "Tgid:");
ppids = strstr(bf, "PPid:");
if (name) {
name += 5; /* strlen("Name:") */
@ -103,32 +107,45 @@ static pid_t perf_event__get_comm_tgid(pid_t pid, char *comm, size_t len)
if (tgids) {
tgids += 5; /* strlen("Tgid:") */
tgid = atoi(tgids);
*tgid = atoi(tgids);
} else {
pr_debug("Tgid: string not found for pid %d\n", pid);
}
return tgid;
if (ppids) {
ppids += 5; /* strlen("PPid:") */
*ppid = atoi(ppids);
} else {
pr_debug("PPid: string not found for pid %d\n", pid);
}
return 0;
}
static pid_t perf_event__prepare_comm(union perf_event *event, pid_t pid,
struct machine *machine)
static int perf_event__prepare_comm(union perf_event *event, pid_t pid,
struct machine *machine,
pid_t *tgid, pid_t *ppid)
{
size_t size;
pid_t tgid;
*ppid = -1;
memset(&event->comm, 0, sizeof(event->comm));
if (machine__is_host(machine))
tgid = perf_event__get_comm_tgid(pid, event->comm.comm,
sizeof(event->comm.comm));
else
tgid = machine->pid;
if (machine__is_host(machine)) {
if (perf_event__get_comm_ids(pid, event->comm.comm,
sizeof(event->comm.comm),
tgid, ppid) != 0) {
return -1;
}
} else {
*tgid = machine->pid;
}
if (tgid < 0)
goto out;
if (*tgid < 0)
return -1;
event->comm.pid = tgid;
event->comm.pid = *tgid;
event->comm.header.type = PERF_RECORD_COMM;
size = strlen(event->comm.comm) + 1;
@ -138,8 +155,8 @@ static pid_t perf_event__prepare_comm(union perf_event *event, pid_t pid,
(sizeof(event->comm.comm) - size) +
machine->id_hdr_size);
event->comm.tid = pid;
out:
return tgid;
return 0;
}
static pid_t perf_event__synthesize_comm(struct perf_tool *tool,
@ -147,27 +164,27 @@ static pid_t perf_event__synthesize_comm(struct perf_tool *tool,
perf_event__handler_t process,
struct machine *machine)
{
pid_t tgid = perf_event__prepare_comm(event, pid, machine);
pid_t tgid, ppid;
if (tgid == -1)
goto out;
if (perf_event__prepare_comm(event, pid, machine, &tgid, &ppid) != 0)
return -1;
if (process(tool, event, &synth_sample, machine) != 0)
return -1;
out:
return tgid;
}
static int perf_event__synthesize_fork(struct perf_tool *tool,
union perf_event *event, pid_t pid,
pid_t tgid, perf_event__handler_t process,
union perf_event *event,
pid_t pid, pid_t tgid, pid_t ppid,
perf_event__handler_t process,
struct machine *machine)
{
memset(&event->fork, 0, sizeof(event->fork) + machine->id_hdr_size);
event->fork.ppid = tgid;
event->fork.ptid = tgid;
event->fork.ppid = ppid;
event->fork.ptid = ppid;
event->fork.pid = tgid;
event->fork.tid = pid;
event->fork.header.type = PERF_RECORD_FORK;
@ -359,7 +376,7 @@ static int __event__synthesize_thread(union perf_event *comm_event,
char filename[PATH_MAX];
DIR *tasks;
struct dirent dirent, *next;
pid_t tgid;
pid_t tgid, ppid;
/* special case: only send one comm event using passed in pid */
if (!full) {
@ -394,12 +411,12 @@ static int __event__synthesize_thread(union perf_event *comm_event,
if (*end)
continue;
tgid = perf_event__prepare_comm(comm_event, _pid, machine);
if (tgid == -1)
if (perf_event__prepare_comm(comm_event, _pid, machine,
&tgid, &ppid) != 0)
return -1;
if (perf_event__synthesize_fork(tool, fork_event, _pid, tgid,
process, machine) < 0)
ppid, process, machine) < 0)
return -1;
/*
* Send the prepared comm event