Commit 48659d31 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

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: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 49ff5903

include/linux/ftrace_event.h

+0 −1
Original line number Diff line number Diff line
@@ -34,7 +34,6 @@ struct trace_entry { 
	unsigned char		flags;

	unsigned char		preempt_count;

	int			pid;

	int			tgid;

};



#define FTRACE_MAX_EVENT						\

kernel/trace/trace.c

+1 −1
Original line number Diff line number Diff line
@@ -886,7 +886,6 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, 


	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 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) 
		return;

	entry	= ring_buffer_event_data(event);



	entry->tgid		= current->tgid;

	memset(&entry->caller, 0, sizeof(entry->caller));



	trace.nr_entries	= 0;

kernel/trace/trace.h

+1 −0
Original line number Diff line number Diff line
@@ -101,6 +101,7 @@ struct stack_entry { 


struct userstack_entry {

	struct trace_entry	ent;

	unsigned int		tgid;

	unsigned long		caller[FTRACE_STACK_ENTRIES];

};

kernel/trace/trace_events.c

+1 −4
Original line number Diff line number Diff line
@@ -86,7 +86,6 @@ int trace_define_common_fields(struct ftrace_event_call *call) 
	__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 @@ static int trace_write_header(struct trace_seq *s) 
				"\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

kernel/trace/trace_output.c

+1 −1
Original line number Diff line number Diff line
@@ -407,7 +407,7 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s, 
		 * 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();

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