tracing: Add saved_tgids file to show cached pid to tgid mappings (99c621d7) · Commits · 戴 / test

kernel/trace/trace.c

+73 −0

Original line number	Diff line number	Diff line
		@@ -4688,6 +4688,76 @@ static const struct file_operations tracing_readme_fops = {
		.llseek = generic_file_llseek,
		};

		static void saved_tgids_next(struct seq_file m, void v, loff_t pos)
		{
		int *ptr = v;

		if (*pos \|\| m->count)
		ptr++;

		(*pos)++;

		for (; ptr <= &tgid_map[PID_MAX_DEFAULT]; ptr++) {
		if (trace_find_tgid(*ptr))
		return ptr;
		}

		return NULL;
		}

		static void saved_tgids_start(struct seq_file m, loff_t *pos)
		{
		void *v;
		loff_t l = 0;

		if (!tgid_map)
		return NULL;

		v = &tgid_map[0];
		while (l <= *pos) {
		v = saved_tgids_next(m, v, &l);
		if (!v)
		return NULL;
		}

		return v;
		}

		static void saved_tgids_stop(struct seq_file m, void v)
		{
		}

		static int saved_tgids_show(struct seq_file m, void v)
		{
		int pid = (int *)v - tgid_map;

		seq_printf(m, "%d %d\n", pid, trace_find_tgid(pid));
		return 0;
		}

		static const struct seq_operations tracing_saved_tgids_seq_ops = {
		.start = saved_tgids_start,
		.stop = saved_tgids_stop,
		.next = saved_tgids_next,
		.show = saved_tgids_show,
		};

		static int tracing_saved_tgids_open(struct inode inode, struct file filp)
		{
		if (tracing_disabled)
		return -ENODEV;

		return seq_open(filp, &tracing_saved_tgids_seq_ops);
		}


		static const struct file_operations tracing_saved_tgids_fops = {
		.open = tracing_saved_tgids_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = seq_release,
		};

		static void saved_cmdlines_next(struct seq_file m, void v, loff_t pos)
		{
		unsigned int *ptr = v;
		@@ -7920,6 +7990,9 @@ static __init int tracer_init_tracefs(void)
		trace_create_file("saved_cmdlines_size", 0644, d_tracer,
		NULL, &tracing_saved_cmdlines_size_fops);

		trace_create_file("saved_tgids", 0444, d_tracer,
		NULL, &tracing_saved_tgids_fops);

		trace_eval_init();

		trace_create_eval_file(d_tracer);

Admin message