tracing: move tgid out of generic entry and into userstack
The userstack trace required the recording of the tgid entry.
Unfortunately, it was added to the generic entry where it wasted
4 bytes of every entry and was only used by one entry.
This patch moves it out of the generic field and moves it into the
only user (userstack_entry).
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 23f7179..06c795b 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -34,7 +34,6 @@
unsigned char flags;
unsigned char preempt_count;
int pid;
- int tgid;
};
#define FTRACE_MAX_EVENT \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5c75dee..1a37da2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -886,7 +886,6 @@
entry->preempt_count = pc & 0xff;
entry->pid = (tsk) ? tsk->pid : 0;
- entry->tgid = (tsk) ? tsk->tgid : 0;
entry->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
@@ -1068,6 +1067,7 @@
return;
entry = ring_buffer_event_data(event);
+ entry->tgid = current->tgid;
memset(&entry->caller, 0, sizeof(entry->caller));
trace.nr_entries = 0;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index acaa680..b69697b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -101,6 +101,7 @@
struct userstack_entry {
struct trace_entry ent;
+ unsigned int tgid;
unsigned long caller[FTRACE_STACK_ENTRIES];
};
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 78b1ed2..28d9202 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -86,7 +86,6 @@
__common_field(unsigned char, flags);
__common_field(unsigned char, preempt_count);
__common_field(int, pid);
- __common_field(int, tgid);
return ret;
}
@@ -572,13 +571,11 @@
"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
- "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
"\n",
FIELD(unsigned short, type),
FIELD(unsigned char, flags),
FIELD(unsigned char, preempt_count),
- FIELD(int, pid),
- FIELD(int, tgid));
+ FIELD(int, pid));
}
static ssize_t
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index e0c2545..be34a6a 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -407,7 +407,7 @@
* since individual threads might have already quit!
*/
rcu_read_lock();
- task = find_task_by_vpid(entry->ent.tgid);
+ task = find_task_by_vpid(entry->tgid);
if (task)
mm = get_task_mm(task);
rcu_read_unlock();