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Commit af6a29bc authored by Tom Zanussi's avatar Tom Zanussi Committed by Steven Rostedt (VMware)
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tracing: Generalize per-element hist trigger data 

Up until now, hist triggers only needed per-element support for saving
'comm' data, which was saved directly as a private data pointer.

In anticipation of the need to save other data besides 'comm', add a
new hist_elt_data struct for the purpose, and switch the current
'comm'-related code over to that.

Link: http://lkml.kernel.org/r/4502c338c965ddf5fc19fb1ec4764391e001ed4b.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 100719dc

kernel/trace/trace_events_hist.c

+43 −33
Original line number Diff line number Diff line
@@ -289,6 +289,10 @@ static struct hist_field *find_var(struct hist_trigger_data *hist_data, 
	return NULL;

}



struct hist_elt_data {

	char *comm;

};



static const char *hist_field_name(struct hist_field *field,

				   unsigned int level)

{
@@ -503,45 +507,61 @@ static inline void save_comm(char *comm, struct task_struct *task) 
	memcpy(comm, task->comm, TASK_COMM_LEN);

}



static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt)

static void hist_elt_data_free(struct hist_elt_data *elt_data)

{

	kfree((char *)elt->private_data);

	kfree(elt_data->comm);

	kfree(elt_data);

}



static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt)

static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)

{

	struct hist_elt_data *elt_data = elt->private_data;



	hist_elt_data_free(elt_data);

}



static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)

{

	struct hist_trigger_data *hist_data = elt->map->private_data;

	unsigned int size = TASK_COMM_LEN;

	struct hist_elt_data *elt_data;

	struct hist_field *key_field;

	unsigned int i;



	elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);

	if (!elt_data)

		return -ENOMEM;



	for_each_hist_key_field(i, hist_data) {

		key_field = hist_data->fields[i];



		if (key_field->flags & HIST_FIELD_FL_EXECNAME) {

			unsigned int size = TASK_COMM_LEN + 1;



			elt->private_data = kzalloc(size, GFP_KERNEL);

			if (!elt->private_data)

			elt_data->comm = kzalloc(size, GFP_KERNEL);

			if (!elt_data->comm) {

				kfree(elt_data);

				return -ENOMEM;

			}

			break;

		}

	}



	elt->private_data = elt_data;



	return 0;

}



static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)

static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)

{

	char *comm = elt->private_data;

	struct hist_elt_data *elt_data = elt->private_data;



	if (comm)

		save_comm(comm, current);

	if (elt_data->comm)

		save_comm(elt_data->comm, current);

}



static const struct tracing_map_ops hist_trigger_elt_comm_ops = {

	.elt_alloc	= hist_trigger_elt_comm_alloc,

	.elt_free	= hist_trigger_elt_comm_free,

	.elt_init	= hist_trigger_elt_comm_init,

static const struct tracing_map_ops hist_trigger_elt_data_ops = {

	.elt_alloc	= hist_trigger_elt_data_alloc,

	.elt_free	= hist_trigger_elt_data_free,

	.elt_init	= hist_trigger_elt_data_init,

};



static const char *get_hist_field_flags(struct hist_field *hist_field)
@@ -1484,21 +1504,6 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) 
	return 0;

}



static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)

{

	struct hist_field *key_field;

	unsigned int i;



	for_each_hist_key_field(i, hist_data) {

		key_field = hist_data->fields[i];



		if (key_field->flags & HIST_FIELD_FL_EXECNAME)

			return true;

	}



	return false;

}



static struct hist_trigger_data *

create_hist_data(unsigned int map_bits,

		 struct hist_trigger_attrs *attrs,
@@ -1524,8 +1529,7 @@ create_hist_data(unsigned int map_bits, 
	if (ret)

		goto free;



	if (need_tracing_map_ops(hist_data))

		map_ops = &hist_trigger_elt_comm_ops;

	map_ops = &hist_trigger_elt_data_ops;



	hist_data->map = tracing_map_create(map_bits, hist_data->key_size,

					    map_ops, hist_data);
@@ -1713,7 +1717,13 @@ hist_trigger_entry_print(struct seq_file *m, 
			seq_printf(m, "%s: [%llx] %-55s", field_name,

				   uval, str);

		} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {

			char *comm = elt->private_data;

			struct hist_elt_data *elt_data = elt->private_data;

			char *comm;



			if (WARN_ON_ONCE(!elt_data))

				return;



			comm = elt_data->comm;



			uval = *(u64 *)(key + key_field->offset);

			seq_printf(m, "%s: %-16s[%10llu]", field_name,