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Commit 5463bfda authored Mar 03, 2016 by Tom Zanussi Committed by Steven Rostedt Apr 19, 2016

tracing: Add support for named hist triggers

Allow users to define 'named' hist triggers.  All triggers created
with the same 'name=xxx' option will update the same shared histogram
data.

This expands the hist trigger syntax from this:

    # echo hist:keys=xxx ... [ if filter] > event/trigger

to this:

    # echo hist:name=xxx:keys=xxx ... [ if filter] > event/trigger

Named histograms must use a 'compatible' set of keys and values, which
means each event added to a set of named triggers must have the same
names and types.

Reading the 'hist' file of any of the participating events will
produce the same output as any other participating event, which is to
be expected since they share the same data.

Link: http://lkml.kernel.org/r/1dbc84ee3322a75daaf5b3ef1d0cc0a2fb682fc7.1457029949.git.tom.zanussi@linux.intel.com



Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent db1388b4

Documentation/trace/events.txt

+266 −8

Original line number	Diff line number	Diff line
		@@ -524,7 +524,7 @@ The following commands are supported:

		hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>]
		[:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue]
		[:clear] [if <filter>]
		[:clear][:name=histname1] [if <filter>]

		When a matching event is hit, an entry is added to a hash table
		using the key(s) and value(s) named. Keys and values correspond to
		@@ -546,18 +546,28 @@ The following commands are supported:
		specified by the 'sort' keyword. If more than one field is
		specified, the result will be a 'sort within a sort': the first key
		is taken to be the primary sort key and the second the secondary
		key.
		key. If a hist trigger is given a name using the 'name' parameter,
		its histogram data will be shared with other triggers of the same
		name, and trigger hits will update this common data. Only triggers
		with 'compatible' fields can be combined in this way; triggers are
		'compatible' if the fields named in the trigger share the same
		number and type of fields and those fields also have the same names.
		Note that any two events always share the compatible 'hitcount' and
		'stacktrace' fields and can therefore be combined using those
		fields, however pointless that may be.

		'hist' triggers add a 'hist' file to each event's subdirectory.
		Reading the 'hist' file for the event will dump the hash table in
		its entirety to stdout. If there are multiple hist triggers
		attached to an event, there will be a table for each trigger in the
		output. Each printed hash table entry is a simple list of the keys
		and values comprising the entry; keys are printed first and are
		delineated by curly braces, and are followed by the set of value
		fields for the entry. By default, numeric fields are displayed as
		base-10 integers. This can be modified by appending any of the
		following modifiers to the field name:
		output. The table displayed for a named trigger will be the same as
		any other instance having the same name. Each printed hash table
		entry is a simple list of the keys and values comprising the entry;
		keys are printed first and are delineated by curly braces, and are
		followed by the set of value fields for the entry. By default,
		numeric fields are displayed as base-10 integers. This can be
		modified by appending any of the following modifiers to the field
		name:

		.hex display a number as a hex value
		.sym display an address as a symbol
		@@ -1809,3 +1819,251 @@ The following commands are supported:
		Hits: 0
		Entries: 0
		Dropped: 0

		Named triggers can be used to have triggers share a common set of
		histogram data. This capability is mostly useful for combining the
		output of events generated by tracepoints contained inside inline
		functions, but names can be used in a hist trigger on any event.
		For example, these two triggers when hit will update the same 'len'
		field in the shared 'foo' histogram data:

		# echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
		/sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
		# echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
		/sys/kernel/debug/tracing/events/net/netif_rx/trigger

		You can see that they're updating common histogram data by reading
		each event's hist files at the same time:

		# cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist;
		cat /sys/kernel/debug/tracing/events/net/netif_rx/hist

		# event histogram
		#
		# trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
		#

		{ skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
		{ skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
		{ skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
		{ skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
		{ skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
		{ skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
		{ skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
		{ skbaddr: ffff880064505000 } hitcount: 1 len: 46
		{ skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
		{ skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
		{ skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
		{ skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
		{ skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
		{ skbaddr: ffff880064505f00 } hitcount: 1 len: 174
		{ skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
		{ skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
		{ skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
		{ skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
		{ skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
		{ skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
		{ skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
		{ skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
		{ skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
		{ skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
		{ skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
		{ skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
		{ skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
		{ skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
		{ skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
		{ skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
		{ skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
		{ skbaddr: ffff880064504400 } hitcount: 4 len: 184
		{ skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
		{ skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
		{ skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
		{ skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
		{ skbaddr: ffff88006a54f900 } hitcount: 6 len: 276

		Totals:
		Hits: 81
		Entries: 42
		Dropped: 0
		# event histogram
		#
		# trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
		#

		{ skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
		{ skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
		{ skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
		{ skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
		{ skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
		{ skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
		{ skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
		{ skbaddr: ffff880064505000 } hitcount: 1 len: 46
		{ skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
		{ skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
		{ skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
		{ skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
		{ skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
		{ skbaddr: ffff880064505f00 } hitcount: 1 len: 174
		{ skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
		{ skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
		{ skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
		{ skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
		{ skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
		{ skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
		{ skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
		{ skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
		{ skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
		{ skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
		{ skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
		{ skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
		{ skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
		{ skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
		{ skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
		{ skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
		{ skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
		{ skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
		{ skbaddr: ffff880064504400 } hitcount: 4 len: 184
		{ skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
		{ skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
		{ skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
		{ skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
		{ skbaddr: ffff88006a54f900 } hitcount: 6 len: 276

		Totals:
		Hits: 81
		Entries: 42
		Dropped: 0

		And here's an example that shows how to combine histogram data from
		any two events even if they don't share any 'compatible' fields
		other than 'hitcount' and 'stacktrace'. These commands create a
		couple of triggers named 'bar' using those fields:

		# echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
		/sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
		# echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
		/sys/kernel/debug/tracing/events/net/netif_rx/trigger

		And displaying the output of either shows some interesting if
		somewhat confusing output:

		# cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
		# cat /sys/kernel/debug/tracing/events/net/netif_rx/hist

		# event histogram
		#
		# trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active]
		#

		{ stacktrace:
		_do_fork+0x18e/0x330
		kernel_thread+0x29/0x30
		kthreadd+0x154/0x1b0
		ret_from_fork+0x3f/0x70
		} hitcount: 1
		{ stacktrace:
		netif_rx_internal+0xb2/0xd0
		netif_rx_ni+0x20/0x70
		dev_loopback_xmit+0xaa/0xd0
		ip_mc_output+0x126/0x240
		ip_local_out_sk+0x31/0x40
		igmp_send_report+0x1e9/0x230
		igmp_timer_expire+0xe9/0x120
		call_timer_fn+0x39/0xf0
		run_timer_softirq+0x1e1/0x290
		__do_softirq+0xfd/0x290
		irq_exit+0x98/0xb0
		smp_apic_timer_interrupt+0x4a/0x60
		apic_timer_interrupt+0x6d/0x80
		cpuidle_enter+0x17/0x20
		call_cpuidle+0x3b/0x60
		cpu_startup_entry+0x22d/0x310
		} hitcount: 1
		{ stacktrace:
		netif_rx_internal+0xb2/0xd0
		netif_rx_ni+0x20/0x70
		dev_loopback_xmit+0xaa/0xd0
		ip_mc_output+0x17f/0x240
		ip_local_out_sk+0x31/0x40
		ip_send_skb+0x1a/0x50
		udp_send_skb+0x13e/0x270
		udp_sendmsg+0x2bf/0x980
		inet_sendmsg+0x67/0xa0
		sock_sendmsg+0x38/0x50
		SYSC_sendto+0xef/0x170
		SyS_sendto+0xe/0x10
		entry_SYSCALL_64_fastpath+0x12/0x6a
		} hitcount: 2
		{ stacktrace:
		netif_rx_internal+0xb2/0xd0
		netif_rx+0x1c/0x60
		loopback_xmit+0x6c/0xb0
		dev_hard_start_xmit+0x219/0x3a0
		__dev_queue_xmit+0x415/0x4f0
		dev_queue_xmit_sk+0x13/0x20
		ip_finish_output2+0x237/0x340
		ip_finish_output+0x113/0x1d0
		ip_output+0x66/0xc0
		ip_local_out_sk+0x31/0x40
		ip_send_skb+0x1a/0x50
		udp_send_skb+0x16d/0x270
		udp_sendmsg+0x2bf/0x980
		inet_sendmsg+0x67/0xa0
		sock_sendmsg+0x38/0x50
		___sys_sendmsg+0x14e/0x270
		} hitcount: 76
		{ stacktrace:
		netif_rx_internal+0xb2/0xd0
		netif_rx+0x1c/0x60
		loopback_xmit+0x6c/0xb0
		dev_hard_start_xmit+0x219/0x3a0
		__dev_queue_xmit+0x415/0x4f0
		dev_queue_xmit_sk+0x13/0x20
		ip_finish_output2+0x237/0x340
		ip_finish_output+0x113/0x1d0
		ip_output+0x66/0xc0
		ip_local_out_sk+0x31/0x40
		ip_send_skb+0x1a/0x50
		udp_send_skb+0x16d/0x270
		udp_sendmsg+0x2bf/0x980
		inet_sendmsg+0x67/0xa0
		sock_sendmsg+0x38/0x50
		___sys_sendmsg+0x269/0x270
		} hitcount: 77
		{ stacktrace:
		netif_rx_internal+0xb2/0xd0
		netif_rx+0x1c/0x60
		loopback_xmit+0x6c/0xb0
		dev_hard_start_xmit+0x219/0x3a0
		__dev_queue_xmit+0x415/0x4f0
		dev_queue_xmit_sk+0x13/0x20
		ip_finish_output2+0x237/0x340
		ip_finish_output+0x113/0x1d0
		ip_output+0x66/0xc0
		ip_local_out_sk+0x31/0x40
		ip_send_skb+0x1a/0x50
		udp_send_skb+0x16d/0x270
		udp_sendmsg+0x2bf/0x980
		inet_sendmsg+0x67/0xa0
		sock_sendmsg+0x38/0x50
		SYSC_sendto+0xef/0x170
		} hitcount: 88
		{ stacktrace:
		_do_fork+0x18e/0x330
		SyS_clone+0x19/0x20
		entry_SYSCALL_64_fastpath+0x12/0x6a
		} hitcount: 244

		Totals:
		Hits: 489
		Entries: 7
		Dropped: 0

kernel/trace/trace.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -3842,6 +3842,7 @@ static const char readme_msg[] =
		"\t [:sort=<field1[,field2,...]>]\n"
		"\t [:size=#entries]\n"
		"\t [:pause][:continue][:clear]\n"
		"\t [:name=histname1]\n"
		"\t [if <filter>]\n\n"
		"\t When a matching event is hit, an entry is added to a hash\n"
		"\t table using the key(s) and value(s) named, and the value of a\n"
		@@ -3854,13 +3855,18 @@ static const char readme_msg[] =
		"\t specified using the 'sort' keyword. The sort direction can\n"
		"\t be modified by appending '.descending' or '.ascending' to a\n"
		"\t sort field. The 'size' parameter can be used to specify more\n"
		"\t or fewer than the default 2048 entries for the hashtable size.\n\n"
		"\t or fewer than the default 2048 entries for the hashtable size.\n"
		"\t If a hist trigger is given a name using the 'name' parameter,\n"
		"\t its histogram data will be shared with other triggers of the\n"
		"\t same name, and trigger hits will update this common data.\n\n"
		"\t Reading the 'hist' file for the event will dump the hash\n"
		"\t table in its entirety to stdout. If there are multiple hist\n"
		"\t triggers attached to an event, there will be a table for each\n"
		"\t trigger in the output. The default format used to display a\n"
		"\t given field can be modified by appending any of the following\n"
		"\t modifiers to the field name, as applicable:\n\n"
		"\t trigger in the output. The table displayed for a named\n"
		"\t trigger will be the same as any other instance having the\n"
		"\t same name. The default format used to display a given field\n"
		"\t can be modified by appending any of the following modifiers\n"
		"\t to the field name, as applicable:\n\n"
		"\t .hex display a number as a hex value\n"
		"\t .sym display an address as a symbol\n"
		"\t .sym-offset display an address as a symbol and offset\n"

kernel/trace/trace_events_hist.c

+131 −17

Original line number	Diff line number	Diff line
		@@ -117,6 +117,7 @@ struct hist_trigger_attrs {
		char *keys_str;
		char *vals_str;
		char *sort_key_str;
		char *name;
		bool pause;
		bool cont;
		bool clear;
		@@ -200,6 +201,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
		if (!attrs)
		return;

		kfree(attrs->name);
		kfree(attrs->sort_key_str);
		kfree(attrs->keys_str);
		kfree(attrs->vals_str);
		@@ -227,6 +229,8 @@ static struct hist_trigger_attrs parse_hist_trigger_attrs(char trigger_str)
		attrs->vals_str = kstrdup(str, GFP_KERNEL);
		else if (strncmp(str, "sort=", strlen("sort=")) == 0)
		attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
		else if (strncmp(str, "name=", strlen("name=")) == 0)
		attrs->name = kstrdup(str, GFP_KERNEL);
		else if (strcmp(str, "pause") == 0)
		attrs->pause = true;
		else if ((strcmp(str, "cont") == 0) \|\|
		@@ -1131,7 +1135,12 @@ static int event_hist_trigger_print(struct seq_file *m,
		struct hist_field *key_field;
		unsigned int i;

		seq_puts(m, "hist:keys=");
		seq_puts(m, "hist:");

		if (data->name)
		seq_printf(m, "%s:", data->name);

		seq_puts(m, "keys=");

		for_each_hist_key_field(i, hist_data) {
		key_field = hist_data->fields[i];
		@@ -1196,6 +1205,19 @@ static int event_hist_trigger_print(struct seq_file *m,
		return 0;
		}

		static int event_hist_trigger_init(struct event_trigger_ops *ops,
		struct event_trigger_data *data)
		{
		struct hist_trigger_data *hist_data = data->private_data;

		if (!data->ref && hist_data->attrs->name)
		save_named_trigger(hist_data->attrs->name, data);

		data->ref++;

		return 0;
		}

		static void event_hist_trigger_free(struct event_trigger_ops *ops,
		struct event_trigger_data *data)
		{
		@@ -1206,6 +1228,8 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops,

		data->ref--;
		if (!data->ref) {
		if (data->name)
		del_named_trigger(data);
		trigger_data_free(data);
		destroy_hist_data(hist_data);
		}
		@@ -1214,10 +1238,44 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops,
		static struct event_trigger_ops event_hist_trigger_ops = {
		.func = event_hist_trigger,
		.print = event_hist_trigger_print,
		.init = event_trigger_init,
		.init = event_hist_trigger_init,
		.free = event_hist_trigger_free,
		};

		static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
		struct event_trigger_data *data)
		{
		data->ref++;

		save_named_trigger(data->named_data->name, data);

		event_hist_trigger_init(ops, data->named_data);

		return 0;
		}

		static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
		struct event_trigger_data *data)
		{
		if (WARN_ON_ONCE(data->ref <= 0))
		return;

		event_hist_trigger_free(ops, data->named_data);

		data->ref--;
		if (!data->ref) {
		del_named_trigger(data);
		trigger_data_free(data);
		}
		}

		static struct event_trigger_ops event_hist_trigger_named_ops = {
		.func = event_hist_trigger,
		.print = event_hist_trigger_print,
		.init = event_hist_trigger_named_init,
		.free = event_hist_trigger_named_free,
		};

		static struct event_trigger_ops event_hist_get_trigger_ops(char cmd,
		char *param)
		{
		@@ -1227,26 +1285,54 @@ static struct event_trigger_ops event_hist_get_trigger_ops(char cmd,
		static void hist_clear(struct event_trigger_data *data)
		{
		struct hist_trigger_data *hist_data = data->private_data;
		bool paused;

		paused = data->paused;
		data->paused = true;
		if (data->name)
		pause_named_trigger(data);

		synchronize_sched();

		tracing_map_clear(hist_data->map);

		data->paused = paused;
		if (data->name)
		unpause_named_trigger(data);
		}

		static bool compatible_field(struct ftrace_event_field *field,
		struct ftrace_event_field *test_field)
		{
		if (field == test_field)
		return true;
		if (field == NULL \|\| test_field == NULL)
		return false;
		if (strcmp(field->name, test_field->name) != 0)
		return false;
		if (strcmp(field->type, test_field->type) != 0)
		return false;
		if (field->size != test_field->size)
		return false;
		if (field->is_signed != test_field->is_signed)
		return false;

		return true;
		}

		static bool hist_trigger_match(struct event_trigger_data *data,
		struct event_trigger_data *data_test)
		struct event_trigger_data *data_test,
		struct event_trigger_data *named_data,
		bool ignore_filter)
		{
		struct tracing_map_sort_key sort_key, sort_key_test;
		struct hist_trigger_data hist_data, hist_data_test;
		struct hist_field key_field, key_field_test;
		unsigned int i;

		if (named_data && (named_data != data_test) &&
		(named_data != data_test->named_data))
		return false;

		if (!named_data && is_named_trigger(data_test))
		return false;

		hist_data = data->private_data;
		hist_data_test = data_test->private_data;

		@@ -1255,9 +1341,11 @@ static bool hist_trigger_match(struct event_trigger_data *data,
		hist_data->n_sort_keys != hist_data_test->n_sort_keys)
		return false;

		if (!ignore_filter) {
		if ((data->filter_str && !data_test->filter_str) \|\|
		(!data->filter_str && data_test->filter_str))
		return false;
		}

		for_each_hist_field(i, hist_data) {
		key_field = hist_data->fields[i];
		@@ -1265,7 +1353,7 @@ static bool hist_trigger_match(struct event_trigger_data *data,

		if (key_field->flags != key_field_test->flags)
		return false;
		if (key_field->field != key_field_test->field)
		if (!compatible_field(key_field->field, key_field_test->field))
		return false;
		if (key_field->offset != key_field_test->offset)
		return false;
		@@ -1280,7 +1368,7 @@ static bool hist_trigger_match(struct event_trigger_data *data,
		return false;
		}

		if (data->filter_str &&
		if (!ignore_filter && data->filter_str &&
		(strcmp(data->filter_str, data_test->filter_str) != 0))
		return false;

		@@ -1292,12 +1380,26 @@ static int hist_register_trigger(char glob, struct event_trigger_ops ops,
		struct trace_event_file *file)
		{
		struct hist_trigger_data *hist_data = data->private_data;
		struct event_trigger_data *test;
		struct event_trigger_data test, named_data = NULL;
		int ret = 0;

		if (hist_data->attrs->name) {
		named_data = find_named_trigger(hist_data->attrs->name);
		if (named_data) {
		if (!hist_trigger_match(data, named_data, named_data,
		true)) {
		ret = -EINVAL;
		goto out;
		}
		}
		}

		if (hist_data->attrs->name && !named_data)
		goto new;

		list_for_each_entry_rcu(test, &file->triggers, list) {
		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
		if (!hist_trigger_match(data, test))
		if (!hist_trigger_match(data, test, named_data, false))
		continue;
		if (hist_data->attrs->pause)
		test->paused = true;
		@@ -1310,12 +1412,19 @@ static int hist_register_trigger(char glob, struct event_trigger_ops ops,
		goto out;
		}
		}

		new:
		if (hist_data->attrs->cont \|\| hist_data->attrs->clear) {
		ret = -ENOENT;
		goto out;
		}

		if (named_data) {
		destroy_hist_data(data->private_data);
		data->private_data = named_data->private_data;
		set_named_trigger_data(data, named_data);
		data->ops = &event_hist_trigger_named_ops;
		}

		if (hist_data->attrs->pause)
		data->paused = true;

		@@ -1329,6 +1438,7 @@ static int hist_register_trigger(char glob, struct event_trigger_ops ops,
		ret++;

		update_cond_flag(file);

		if (trace_event_trigger_enable_disable(file, 1) < 0) {
		list_del_rcu(&data->list);
		update_cond_flag(file);
		@@ -1342,12 +1452,16 @@ static void hist_unregister_trigger(char glob, struct event_trigger_ops ops,
		struct event_trigger_data *data,
		struct trace_event_file *file)
		{
		struct event_trigger_data *test;
		struct hist_trigger_data *hist_data = data->private_data;
		struct event_trigger_data test, named_data = NULL;
		bool unregistered = false;

		if (hist_data->attrs->name)
		named_data = find_named_trigger(hist_data->attrs->name);

		list_for_each_entry_rcu(test, &file->triggers, list) {
		if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
		if (!hist_trigger_match(data, test))
		if (!hist_trigger_match(data, test, named_data, false))
		continue;
		unregistered = true;
		list_del_rcu(&test->list);