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Commit 30350d65 authored by Tom Zanussi's avatar Tom Zanussi Committed by Steven Rostedt (VMware)
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tracing: Add variable support to hist triggers 

Add support for saving the value of a current event's event field by
assigning it to a variable that can be read by a subsequent event.

The basic syntax for saving a variable is to simply prefix a unique
variable name not corresponding to any keyword along with an '=' sign
to any event field.

Both keys and values can be saved and retrieved in this way:

    # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ...
    # echo 'hist:timer_pid=common_pid:key=$timer_pid ...'

If a variable isn't a key variable or prefixed with 'vals=', the
associated event field will be saved in a variable but won't be summed
as a value:

    # echo 'hist:keys=next_pid:ts1=common_timestamp:...

Multiple variables can be assigned at the same time:

    # echo 'hist:keys=pid:vals=$ts0,$b,field2:ts0=common_timestamp,b=field1 ...

Multiple (or single) variables can also be assigned at the same time
using separate assignments:

    # echo 'hist:keys=pid:vals=$ts0:ts0=common_timestamp:b=field1:c=field2 ...

Variables set as above can be used by being referenced from another
event, as described in a subsequent patch.

Link: http://lkml.kernel.org/r/fc93c4944d9719dbcb1d0067be627d44e98e2adc.1516069914.git.tom.zanussi@linux.intel.com



Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarBaohong Liu <baohong.liu@intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 860f9f6b

kernel/trace/trace_events_hist.c

+331 −39
Original line number Diff line number Diff line
@@ -30,6 +30,13 @@ typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event, 
				struct ring_buffer_event *rbe);



#define HIST_FIELD_OPERANDS_MAX	2

#define HIST_FIELDS_MAX		(TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)



struct hist_var {

	char				*name;

	struct hist_trigger_data	*hist_data;

	unsigned int			idx;

};



struct hist_field {

	struct ftrace_event_field	*field;
@@ -40,6 +47,7 @@ struct hist_field { 
	unsigned int                    is_signed;

	struct hist_field		*operands[HIST_FIELD_OPERANDS_MAX];

	struct hist_trigger_data	*hist_data;

	struct hist_var			var;

};



static u64 hist_field_none(struct hist_field *field, void *event,
@@ -138,6 +146,13 @@ enum hist_field_flags { 
	HIST_FIELD_FL_LOG2		= 1 << 9,

	HIST_FIELD_FL_TIMESTAMP		= 1 << 10,

	HIST_FIELD_FL_TIMESTAMP_USECS	= 1 << 11,

	HIST_FIELD_FL_VAR		= 1 << 12,

};



struct var_defs {

	unsigned int	n_vars;

	char		*name[TRACING_MAP_VARS_MAX];

	char		*expr[TRACING_MAP_VARS_MAX];

};



struct hist_trigger_attrs {
@@ -150,13 +165,19 @@ struct hist_trigger_attrs { 
	bool		clear;

	bool		ts_in_usecs;

	unsigned int	map_bits;



	char		*assignment_str[TRACING_MAP_VARS_MAX];

	unsigned int	n_assignments;



	struct var_defs	var_defs;

};



struct hist_trigger_data {

	struct hist_field               *fields[TRACING_MAP_FIELDS_MAX];

	struct hist_field               *fields[HIST_FIELDS_MAX];

	unsigned int			n_vals;

	unsigned int			n_keys;

	unsigned int			n_fields;

	unsigned int			n_vars;

	unsigned int			key_size;

	struct tracing_map_sort_key	sort_keys[TRACING_MAP_SORT_KEYS_MAX];

	unsigned int			n_sort_keys;
@@ -164,6 +185,7 @@ struct hist_trigger_data { 
	struct hist_trigger_attrs	*attrs;

	struct tracing_map		*map;

	bool				enable_timestamps;

	bool				remove;

};



static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
@@ -180,6 +202,48 @@ static u64 hist_field_timestamp(struct hist_field *hist_field, void *event, 
	return ts;

}



static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,

					 const char *var_name)

{

	struct hist_field *hist_field, *found = NULL;

	int i;



	for_each_hist_field(i, hist_data) {

		hist_field = hist_data->fields[i];

		if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&

		    strcmp(hist_field->var.name, var_name) == 0) {

			found = hist_field;

			break;

		}

	}



	return found;

}



static struct hist_field *find_var(struct hist_trigger_data *hist_data,

				   struct trace_event_file *file,

				   const char *var_name)

{

	struct hist_trigger_data *test_data;

	struct event_trigger_data *test;

	struct hist_field *hist_field;



	hist_field = find_var_field(hist_data, var_name);

	if (hist_field)

		return hist_field;



	list_for_each_entry_rcu(test, &file->triggers, list) {

		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {

			test_data = test->private_data;

			hist_field = find_var_field(test_data, var_name);

			if (hist_field)

				return hist_field;

		}

	}



	return NULL;

}



static const char *hist_field_name(struct hist_field *field,

				   unsigned int level)

{
@@ -262,9 +326,14 @@ static int parse_map_size(char *str) 


static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)

{

	unsigned int i;



	if (!attrs)

		return;



	for (i = 0; i < attrs->n_assignments; i++)

		kfree(attrs->assignment_str[i]);



	kfree(attrs->name);

	kfree(attrs->sort_key_str);

	kfree(attrs->keys_str);
@@ -311,8 +380,22 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs) 
			goto out;

		}

		attrs->map_bits = map_bits;

	} else

	} else {

		char *assignment;



		if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {

			ret = -EINVAL;

			goto out;

		}



		assignment = kstrdup(str, GFP_KERNEL);

		if (!assignment) {

			ret = -ENOMEM;

			goto out;

		}



		attrs->assignment_str[attrs->n_assignments++] = assignment;

	}

 out:

	return ret;

}
@@ -428,12 +511,15 @@ static void destroy_hist_field(struct hist_field *hist_field, 
	for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)

		destroy_hist_field(hist_field->operands[i], level + 1);



	kfree(hist_field->var.name);



	kfree(hist_field);

}



static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,

					    struct ftrace_event_field *field,

					    unsigned long flags)

					    unsigned long flags,

					    char *var_name)

{

	struct hist_field *hist_field;
@@ -459,7 +545,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, 
	if (flags & HIST_FIELD_FL_LOG2) {

		unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;

		hist_field->fn = hist_field_log2;

		hist_field->operands[0] = create_hist_field(hist_data, field, fl);

		hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);

		hist_field->size = hist_field->operands[0]->size;

		goto out;

	}
@@ -494,14 +580,23 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, 
	hist_field->field = field;

	hist_field->flags = flags;



	if (var_name) {

		hist_field->var.name = kstrdup(var_name, GFP_KERNEL);

		if (!hist_field->var.name)

			goto free;

	}



	return hist_field;

 free:

	destroy_hist_field(hist_field, 0);

	return NULL;

}



static void destroy_hist_fields(struct hist_trigger_data *hist_data)

{

	unsigned int i;



	for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {

	for (i = 0; i < HIST_FIELDS_MAX; i++) {

		if (hist_data->fields[i]) {

			destroy_hist_field(hist_data->fields[i], 0);

			hist_data->fields[i] = NULL;
@@ -512,11 +607,12 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data) 
static int create_hitcount_val(struct hist_trigger_data *hist_data)

{

	hist_data->fields[HITCOUNT_IDX] =

		create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT);

		create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);

	if (!hist_data->fields[HITCOUNT_IDX])

		return -ENOMEM;



	hist_data->n_vals++;

	hist_data->n_fields++;



	if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))

		return -EINVAL;
@@ -524,19 +620,16 @@ static int create_hitcount_val(struct hist_trigger_data *hist_data) 
	return 0;

}



static int create_val_field(struct hist_trigger_data *hist_data,

static int __create_val_field(struct hist_trigger_data *hist_data,

			      unsigned int val_idx,

			      struct trace_event_file *file,

			    char *field_str)

			      char *var_name, char *field_str,

			      unsigned long flags)

{

	struct ftrace_event_field *field = NULL;

	unsigned long flags = 0;

	char *field_name;

	int ret = 0;



	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))

		return -EINVAL;



	field_name = strsep(&field_str, ".");

	if (field_str) {

		if (strcmp(field_str, "hex") == 0)
@@ -558,25 +651,58 @@ static int create_val_field(struct hist_trigger_data *hist_data, 
		}

	}



	hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags);

	hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags, var_name);

	if (!hist_data->fields[val_idx]) {

		ret = -ENOMEM;

		goto out;

	}



	++hist_data->n_vals;

	++hist_data->n_fields;



	if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))

	if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))

		ret = -EINVAL;

 out:

	return ret;

}



static int create_val_field(struct hist_trigger_data *hist_data,

			    unsigned int val_idx,

			    struct trace_event_file *file,

			    char *field_str)

{

	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))

		return -EINVAL;



	return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);

}



static int create_var_field(struct hist_trigger_data *hist_data,

			    unsigned int val_idx,

			    struct trace_event_file *file,

			    char *var_name, char *expr_str)

{

	unsigned long flags = 0;



	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))

		return -EINVAL;

	if (find_var(hist_data, file, var_name) && !hist_data->remove) {

		return -EINVAL;

	}



	flags |= HIST_FIELD_FL_VAR;

	hist_data->n_vars++;

	if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))

		return -EINVAL;



	return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);

}



static int create_val_fields(struct hist_trigger_data *hist_data,

			     struct trace_event_file *file)

{

	char *fields_str, *field_str;

	unsigned int i, j;

	unsigned int i, j = 1;

	int ret;



	ret = create_hitcount_val(hist_data);
@@ -596,12 +722,15 @@ static int create_val_fields(struct hist_trigger_data *hist_data, 
		field_str = strsep(&fields_str, ",");

		if (!field_str)

			break;



		if (strcmp(field_str, "hitcount") == 0)

			continue;



		ret = create_val_field(hist_data, j++, file, field_str);

		if (ret)

			goto out;

	}



	if (fields_str && (strcmp(fields_str, "hitcount") != 0))

		ret = -EINVAL;

 out:
@@ -615,11 +744,12 @@ static int create_key_field(struct hist_trigger_data *hist_data, 
			    char *field_str)

{

	struct ftrace_event_field *field = NULL;

	struct hist_field *hist_field = NULL;

	unsigned long flags = 0;

	unsigned int key_size;

	int ret = 0;



	if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))

	if (WARN_ON(key_idx >= HIST_FIELDS_MAX))

		return -EINVAL;



	flags |= HIST_FIELD_FL_KEY;
@@ -627,6 +757,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, 
	if (strcmp(field_str, "stacktrace") == 0) {

		flags |= HIST_FIELD_FL_STACKTRACE;

		key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;

		hist_field = create_hist_field(hist_data, NULL, flags, NULL);

	} else {

		char *field_name = strsep(&field_str, ".");
@@ -672,7 +803,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, 
		}

	}



	hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags);

	hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags, NULL);

	if (!hist_data->fields[key_idx]) {

		ret = -ENOMEM;

		goto out;
@@ -688,6 +819,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, 
	}



	hist_data->n_keys++;

	hist_data->n_fields++;



	if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))

		return -EINVAL;
@@ -731,21 +863,111 @@ static int create_key_fields(struct hist_trigger_data *hist_data, 
	return ret;

}



static int create_var_fields(struct hist_trigger_data *hist_data,

			     struct trace_event_file *file)

{

	unsigned int i, j = hist_data->n_vals;

	int ret = 0;



	unsigned int n_vars = hist_data->attrs->var_defs.n_vars;



	for (i = 0; i < n_vars; i++) {

		char *var_name = hist_data->attrs->var_defs.name[i];

		char *expr = hist_data->attrs->var_defs.expr[i];



		ret = create_var_field(hist_data, j++, file, var_name, expr);

		if (ret)

			goto out;

	}

 out:

	return ret;

}



static void free_var_defs(struct hist_trigger_data *hist_data)

{

	unsigned int i;



	for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {

		kfree(hist_data->attrs->var_defs.name[i]);

		kfree(hist_data->attrs->var_defs.expr[i]);

	}



	hist_data->attrs->var_defs.n_vars = 0;

}



static int parse_var_defs(struct hist_trigger_data *hist_data)

{

	char *s, *str, *var_name, *field_str;

	unsigned int i, j, n_vars = 0;

	int ret = 0;



	for (i = 0; i < hist_data->attrs->n_assignments; i++) {

		str = hist_data->attrs->assignment_str[i];

		for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {

			field_str = strsep(&str, ",");

			if (!field_str)

				break;



			var_name = strsep(&field_str, "=");

			if (!var_name || !field_str) {

				ret = -EINVAL;

				goto free;

			}



			if (n_vars == TRACING_MAP_VARS_MAX) {

				ret = -EINVAL;

				goto free;

			}



			s = kstrdup(var_name, GFP_KERNEL);

			if (!s) {

				ret = -ENOMEM;

				goto free;

			}

			hist_data->attrs->var_defs.name[n_vars] = s;



			s = kstrdup(field_str, GFP_KERNEL);

			if (!s) {

				kfree(hist_data->attrs->var_defs.name[n_vars]);

				ret = -ENOMEM;

				goto free;

			}

			hist_data->attrs->var_defs.expr[n_vars++] = s;



			hist_data->attrs->var_defs.n_vars = n_vars;

		}

	}



	return ret;

 free:

	free_var_defs(hist_data);



	return ret;

}



static int create_hist_fields(struct hist_trigger_data *hist_data,

			      struct trace_event_file *file)

{

	int ret;



	ret = parse_var_defs(hist_data);

	if (ret)

		goto out;



	ret = create_val_fields(hist_data, file);

	if (ret)

		goto out;



	ret = create_key_fields(hist_data, file);

	ret = create_var_fields(hist_data, file);

	if (ret)

		goto out;



	hist_data->n_fields = hist_data->n_vals + hist_data->n_keys;

	ret = create_key_fields(hist_data, file);

	if (ret)

		goto out;

 out:

	free_var_defs(hist_data);



	return ret;

}
@@ -768,7 +990,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) 
	char *fields_str = hist_data->attrs->sort_key_str;

	struct tracing_map_sort_key *sort_key;

	int descending, ret = 0;

	unsigned int i, j;

	unsigned int i, j, k;



	hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
@@ -816,12 +1038,19 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) 
			continue;

		}



		for (j = 1; j < hist_data->n_fields; j++) {

		for (j = 1, k = 1; j < hist_data->n_fields; j++) {

			unsigned int idx;



			hist_field = hist_data->fields[j];

			if (hist_field->flags & HIST_FIELD_FL_VAR)

				continue;



			idx = k++;



			test_name = hist_field_name(hist_field, 0);



			if (strcmp(field_name, test_name) == 0) {

				sort_key->field_idx = j;

				sort_key->field_idx = idx;

				descending = is_descending(field_str);

				if (descending < 0) {

					ret = descending;
@@ -836,6 +1065,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) 
			break;

		}

	}



	hist_data->n_sort_keys = i;

 out:

	return ret;
@@ -876,12 +1106,19 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) 
			idx = tracing_map_add_key_field(map,

							hist_field->offset,

							cmp_fn);



		} else

		} else if (!(hist_field->flags & HIST_FIELD_FL_VAR))

			idx = tracing_map_add_sum_field(map);



		if (idx < 0)

			return idx;



		if (hist_field->flags & HIST_FIELD_FL_VAR) {

			idx = tracing_map_add_var(map);

			if (idx < 0)

				return idx;

			hist_field->var.idx = idx;

			hist_field->var.hist_data = hist_data;

		}

	}



	return 0;
@@ -905,7 +1142,8 @@ static bool need_tracing_map_ops(struct hist_trigger_data *hist_data) 
static struct hist_trigger_data *

create_hist_data(unsigned int map_bits,

		 struct hist_trigger_attrs *attrs,

		 struct trace_event_file *file)

		 struct trace_event_file *file,

		 bool remove)

{

	const struct tracing_map_ops *map_ops = NULL;

	struct hist_trigger_data *hist_data;
@@ -916,6 +1154,7 @@ create_hist_data(unsigned int map_bits, 
		return ERR_PTR(-ENOMEM);



	hist_data->attrs = attrs;

	hist_data->remove = remove;



	ret = create_hist_fields(hist_data, file);

	if (ret)
@@ -962,14 +1201,28 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, 
				    struct ring_buffer_event *rbe)

{

	struct hist_field *hist_field;

	unsigned int i;

	unsigned int i, var_idx;

	u64 hist_val;



	for_each_hist_val_field(i, hist_data) {

		hist_field = hist_data->fields[i];

		hist_val = hist_field->fn(hist_field, rec, rbe);

		if (hist_field->flags & HIST_FIELD_FL_VAR) {

			var_idx = hist_field->var.idx;

			tracing_map_set_var(elt, var_idx, hist_val);

			continue;

		}

		tracing_map_update_sum(elt, i, hist_val);

	}



	for_each_hist_key_field(i, hist_data) {

		hist_field = hist_data->fields[i];

		if (hist_field->flags & HIST_FIELD_FL_VAR) {

			hist_val = hist_field->fn(hist_field, rec, rbe);

			var_idx = hist_field->var.idx;

			tracing_map_set_var(elt, var_idx, hist_val);

		}

	}

}



static inline void add_to_key(char *compound_key, void *key,
@@ -1144,6 +1397,9 @@ hist_trigger_entry_print(struct seq_file *m, 
	for (i = 1; i < hist_data->n_vals; i++) {

		field_name = hist_field_name(hist_data->fields[i], 0);



		if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR)

			continue;



		if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {

			seq_printf(m, "  %s: %10llx", field_name,

				   tracing_map_read_sum(elt, i));
@@ -1265,6 +1521,9 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) 
{

	const char *field_name = hist_field_name(hist_field, 0);



	if (hist_field->var.name)

		seq_printf(m, "%s=", hist_field->var.name);



	if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)

		seq_puts(m, "common_timestamp");

	else if (field_name)
@@ -1283,7 +1542,8 @@ static int event_hist_trigger_print(struct seq_file *m, 
				    struct event_trigger_data *data)

{

	struct hist_trigger_data *hist_data = data->private_data;

	struct hist_field *key_field;

	struct hist_field *field;

	bool have_var = false;

	unsigned int i;



	seq_puts(m, "hist:");
@@ -1294,25 +1554,47 @@ static int event_hist_trigger_print(struct seq_file *m, 
	seq_puts(m, "keys=");



	for_each_hist_key_field(i, hist_data) {

		key_field = hist_data->fields[i];

		field = hist_data->fields[i];



		if (i > hist_data->n_vals)

			seq_puts(m, ",");



		if (key_field->flags & HIST_FIELD_FL_STACKTRACE)

		if (field->flags & HIST_FIELD_FL_STACKTRACE)

			seq_puts(m, "stacktrace");

		else

			hist_field_print(m, key_field);

			hist_field_print(m, field);

	}



	seq_puts(m, ":vals=");



	for_each_hist_val_field(i, hist_data) {

		field = hist_data->fields[i];

		if (field->flags & HIST_FIELD_FL_VAR) {

			have_var = true;

			continue;

		}



		if (i == HITCOUNT_IDX)

			seq_puts(m, "hitcount");

		else {

			seq_puts(m, ",");

			hist_field_print(m, hist_data->fields[i]);

			hist_field_print(m, field);

		}

	}



	if (have_var) {

		unsigned int n = 0;



		seq_puts(m, ":");



		for_each_hist_val_field(i, hist_data) {

			field = hist_data->fields[i];



			if (field->flags & HIST_FIELD_FL_VAR) {

				if (n++)

					seq_puts(m, ",");

				hist_field_print(m, field);

			}

		}

	}
@@ -1320,7 +1602,10 @@ static int event_hist_trigger_print(struct seq_file *m, 


	for (i = 0; i < hist_data->n_sort_keys; i++) {

		struct tracing_map_sort_key *sort_key;

		unsigned int idx;

		unsigned int idx, first_key_idx;



		/* skip VAR vals */

		first_key_idx = hist_data->n_vals - hist_data->n_vars;



		sort_key = &hist_data->sort_keys[i];

		idx = sort_key->field_idx;
@@ -1333,8 +1618,11 @@ static int event_hist_trigger_print(struct seq_file *m, 


		if (idx == HITCOUNT_IDX)

			seq_puts(m, "hitcount");

		else

		else {

			if (idx >= first_key_idx)

				idx += hist_data->n_vars;

			hist_field_print(m, hist_data->fields[idx]);

		}



		if (sort_key->descending)

			seq_puts(m, ".descending");
@@ -1631,7 +1919,7 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, 
		test->ops->free(test->ops, test);



	if (hist_data->enable_timestamps) {

		if (unregistered)

		if (!hist_data->remove || unregistered)

			tracing_set_time_stamp_abs(file->tr, false);

	}

}
@@ -1664,12 +1952,16 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, 
	struct hist_trigger_attrs *attrs;

	struct event_trigger_ops *trigger_ops;

	struct hist_trigger_data *hist_data;

	bool remove = false;

	char *trigger;

	int ret = 0;



	if (!param)

		return -EINVAL;



	if (glob[0] == '!')

		remove = true;



	/* separate the trigger from the filter (k:v [if filter]) */

	trigger = strsep(&param, " \t");

	if (!trigger)
@@ -1682,7 +1974,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, 
	if (attrs->map_bits)

		hist_trigger_bits = attrs->map_bits;



	hist_data = create_hist_data(hist_trigger_bits, attrs, file);

	hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove);

	if (IS_ERR(hist_data)) {

		destroy_hist_trigger_attrs(attrs);

		return PTR_ERR(hist_data);
@@ -1711,7 +2003,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, 
			goto out_free;

	}



	if (glob[0] == '!') {

	if (remove) {

		cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);

		ret = 0;

		goto out_free;