summaryrefslogtreecommitdiff
path: root/include/linux/perf_event.h
blob: 9e1c3ada91c49b36b643496ffe5fcd37917bb5b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
/*
 * Performance events:
 *
 *    Copyright (C) 2008-2009, Thomas Gleixner <tglx@linutronix.de>
 *    Copyright (C) 2008-2011, Red Hat, Inc., Ingo Molnar
 *    Copyright (C) 2008-2011, Red Hat, Inc., Peter Zijlstra
 *
 * Data type definitions, declarations, prototypes.
 *
 *    Started by: Thomas Gleixner and Ingo Molnar
 *
 * For licencing details see kernel-base/COPYING
 */
#ifndef _LINUX_PERF_EVENT_H
#define _LINUX_PERF_EVENT_H

#include <uapi/linux/perf_event.h>

/*
 * Kernel-internal data types and definitions:
 */

#ifdef CONFIG_PERF_EVENTS
# include <asm/perf_event.h>
# include <asm/local64.h>
#endif

struct perf_guest_info_callbacks {
	int				(*is_in_guest)(void);
	int				(*is_user_mode)(void);
	unsigned long			(*get_guest_ip)(void);
};

#ifdef CONFIG_HAVE_HW_BREAKPOINT
#include <asm/hw_breakpoint.h>
#endif

#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/hrtimer.h>
#include <linux/fs.h>
#include <linux/pid_namespace.h>
#include <linux/workqueue.h>
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/irq_work.h>
#include <linux/static_key.h>
#include <linux/jump_label_ratelimit.h>
#include <linux/atomic.h>
#include <linux/sysfs.h>
#include <linux/perf_regs.h>
#include <linux/workqueue.h>
#include <linux/cgroup.h>
#include <asm/local.h>

struct perf_callchain_entry {
	__u64				nr;
	__u64				ip[0]; /* /proc/sys/kernel/perf_event_max_stack */
};

struct perf_raw_record {
	u32				size;
	void				*data;
};

/*
 * branch stack layout:
 *  nr: number of taken branches stored in entries[]
 *
 * Note that nr can vary from sample to sample
 * branches (to, from) are stored from most recent
 * to least recent, i.e., entries[0] contains the most
 * recent branch.
 */
struct perf_branch_stack {
	__u64				nr;
	struct perf_branch_entry	entries[0];
};

struct task_struct;

/*
 * extra PMU register associated with an event
 */
struct hw_perf_event_extra {
	u64		config;	/* register value */
	unsigned int	reg;	/* register address or index */
	int		alloc;	/* extra register already allocated */
	int		idx;	/* index in shared_regs->regs[] */
};

/**
 * struct hw_perf_event - performance event hardware details:
 */
struct hw_perf_event {
#ifdef CONFIG_PERF_EVENTS
	union {
		struct { /* hardware */
			u64		config;
			u64		last_tag;
			unsigned long	config_base;
			unsigned long	event_base;
			int		event_base_rdpmc;
			int		idx;
			int		last_cpu;
			int		flags;

			struct hw_perf_event_extra extra_reg;
			struct hw_perf_event_extra branch_reg;
		};
		struct { /* software */
			struct hrtimer	hrtimer;
		};
		struct { /* tracepoint */
			/* for tp_event->class */
			struct list_head	tp_list;
		};
		struct { /* intel_cqm */
			int			cqm_state;
			u32			cqm_rmid;
			int			is_group_event;
			struct list_head	cqm_events_entry;
			struct list_head	cqm_groups_entry;
			struct list_head	cqm_group_entry;
		};
		struct { /* itrace */
			int			itrace_started;
		};
		struct { /* amd_power */
			u64	pwr_acc;
			u64	ptsc;
		};
#ifdef CONFIG_HAVE_HW_BREAKPOINT
		struct { /* breakpoint */
			/*
			 * Crufty hack to avoid the chicken and egg
			 * problem hw_breakpoint has with context
			 * creation and event initalization.
			 */
			struct arch_hw_breakpoint	info;
			struct list_head		bp_list;
		};
#endif
	};
	/*
	 * If the event is a per task event, this will point to the task in
	 * question. See the comment in perf_event_alloc().
	 */
	struct task_struct		*target;

	/*
	 * PMU would store hardware filter configuration
	 * here.
	 */
	void				*addr_filters;

	/* Last sync'ed generation of filters */
	unsigned long			addr_filters_gen;

/*
 * hw_perf_event::state flags; used to track the PERF_EF_* state.
 */
#define PERF_HES_STOPPED	0x01 /* the counter is stopped */
#define PERF_HES_UPTODATE	0x02 /* event->count up-to-date */
#define PERF_HES_ARCH		0x04

	int				state;

	/*
	 * The last observed hardware counter value, updated with a
	 * local64_cmpxchg() such that pmu::read() can be called nested.
	 */
	local64_t			prev_count;

	/*
	 * The period to start the next sample with.
	 */
	u64				sample_period;

	/*
	 * The period we started this sample with.
	 */
	u64				last_period;

	/*
	 * However much is left of the current period; note that this is
	 * a full 64bit value and allows for generation of periods longer
	 * than hardware might allow.
	 */
	local64_t			period_left;

	/*
	 * State for throttling the event, see __perf_event_overflow() and
	 * perf_adjust_freq_unthr_context().
	 */
	u64                             interrupts_seq;
	u64				interrupts;

	/*
	 * State for freq target events, see __perf_event_overflow() and
	 * perf_adjust_freq_unthr_context().
	 */
	u64				freq_time_stamp;
	u64				freq_count_stamp;
#endif
};

struct perf_event;

/*
 * Common implementation detail of pmu::{start,commit,cancel}_txn
 */
#define PERF_PMU_TXN_ADD  0x1		/* txn to add/schedule event on PMU */
#define PERF_PMU_TXN_READ 0x2		/* txn to read event group from PMU */

/**
 * pmu::capabilities flags
 */
#define PERF_PMU_CAP_NO_INTERRUPT		0x01
#define PERF_PMU_CAP_NO_NMI			0x02
#define PERF_PMU_CAP_AUX_NO_SG			0x04
#define PERF_PMU_CAP_AUX_SW_DOUBLEBUF		0x08
#define PERF_PMU_CAP_EXCLUSIVE			0x10
#define PERF_PMU_CAP_ITRACE			0x20
#define PERF_PMU_CAP_HETEROGENEOUS_CPUS		0x40

/**
 * struct pmu - generic performance monitoring unit
 */
struct pmu {
	struct list_head		entry;

	struct module			*module;
	struct device			*dev;
	const struct attribute_group	**attr_groups;
	const char			*name;
	int				type;

	/*
	 * various common per-pmu feature flags
	 */
	int				capabilities;

	int * __percpu			pmu_disable_count;
	struct perf_cpu_context * __percpu pmu_cpu_context;
	atomic_t			exclusive_cnt; /* < 0: cpu; > 0: tsk */
	int				task_ctx_nr;
	int				hrtimer_interval_ms;

	/* number of address filters this PMU can do */
	unsigned int			nr_addr_filters;

	/*
	 * Fully disable/enable this PMU, can be used to protect from the PMI
	 * as well as for lazy/batch writing of the MSRs.
	 */
	void (*pmu_enable)		(struct pmu *pmu); /* optional */
	void (*pmu_disable)		(struct pmu *pmu); /* optional */

	/*
	 * Try and initialize the event for this PMU.
	 *
	 * Returns:
	 *  -ENOENT	-- @event is not for this PMU
	 *
	 *  -ENODEV	-- @event is for this PMU but PMU not present
	 *  -EBUSY	-- @event is for this PMU but PMU temporarily unavailable
	 *  -EINVAL	-- @event is for this PMU but @event is not valid
	 *  -EOPNOTSUPP -- @event is for this PMU, @event is valid, but not supported
	 *  -EACCESS	-- @event is for this PMU, @event is valid, but no privilidges
	 *
	 *  0		-- @event is for this PMU and valid
	 *
	 * Other error return values are allowed.
	 */
	int (*event_init)		(struct perf_event *event);

	/*
	 * Notification that the event was mapped or unmapped.  Called
	 * in the context of the mapping task.
	 */
	void (*event_mapped)		(struct perf_event *event); /*optional*/
	void (*event_unmapped)		(struct perf_event *event); /*optional*/

	/*
	 * Flags for ->add()/->del()/ ->start()/->stop(). There are
	 * matching hw_perf_event::state flags.
	 */
#define PERF_EF_START	0x01		/* start the counter when adding    */
#define PERF_EF_RELOAD	0x02		/* reload the counter when starting */
#define PERF_EF_UPDATE	0x04		/* update the counter when stopping */

	/*
	 * Adds/Removes a counter to/from the PMU, can be done inside a
	 * transaction, see the ->*_txn() methods.
	 *
	 * The add/del callbacks will reserve all hardware resources required
	 * to service the event, this includes any counter constraint
	 * scheduling etc.
	 *
	 * Called with IRQs disabled and the PMU disabled on the CPU the event
	 * is on.
	 *
	 * ->add() called without PERF_EF_START should result in the same state
	 *  as ->add() followed by ->stop().
	 *
	 * ->del() must always PERF_EF_UPDATE stop an event. If it calls
	 *  ->stop() that must deal with already being stopped without
	 *  PERF_EF_UPDATE.
	 */
	int  (*add)			(struct perf_event *event, int flags);
	void (*del)			(struct perf_event *event, int flags);

	/*
	 * Starts/Stops a counter present on the PMU.
	 *
	 * The PMI handler should stop the counter when perf_event_overflow()
	 * returns !0. ->start() will be used to continue.
	 *
	 * Also used to change the sample period.
	 *
	 * Called with IRQs disabled and the PMU disabled on the CPU the event
	 * is on -- will be called from NMI context with the PMU generates
	 * NMIs.
	 *
	 * ->stop() with PERF_EF_UPDATE will read the counter and update
	 *  period/count values like ->read() would.
	 *
	 * ->start() with PERF_EF_RELOAD will reprogram the the counter
	 *  value, must be preceded by a ->stop() with PERF_EF_UPDATE.
	 */
	void (*start)			(struct perf_event *event, int flags);
	void (*stop)			(struct perf_event *event, int flags);

	/*
	 * Updates the counter value of the event.
	 *
	 * For sampling capable PMUs this will also update the software period
	 * hw_perf_event::period_left field.
	 */
	void (*read)			(struct perf_event *event);

	/*
	 * Group events scheduling is treated as a transaction, add
	 * group events as a whole and perform one schedulability test.
	 * If the test fails, roll back the whole group
	 *
	 * Start the transaction, after this ->add() doesn't need to
	 * do schedulability tests.
	 *
	 * Optional.
	 */
	void (*start_txn)		(struct pmu *pmu, unsigned int txn_flags);
	/*
	 * If ->start_txn() disabled the ->add() schedulability test
	 * then ->commit_txn() is required to perform one. On success
	 * the transaction is closed. On error the transaction is kept
	 * open until ->cancel_txn() is called.
	 *
	 * Optional.
	 */
	int  (*commit_txn)		(struct pmu *pmu);
	/*
	 * Will cancel the transaction, assumes ->del() is called
	 * for each successful ->add() during the transaction.
	 *
	 * Optional.
	 */
	void (*cancel_txn)		(struct pmu *pmu);

	/*
	 * Will return the value for perf_event_mmap_page::index for this event,
	 * if no implementation is provided it will default to: event->hw.idx + 1.
	 */
	int (*event_idx)		(struct perf_event *event); /*optional */

	/*
	 * context-switches callback
	 */
	void (*sched_task)		(struct perf_event_context *ctx,
					bool sched_in);
	/*
	 * PMU specific data size
	 */
	size_t				task_ctx_size;


	/*
	 * Return the count value for a counter.
	 */
	u64 (*count)			(struct perf_event *event); /*optional*/

	/*
	 * Set up pmu-private data structures for an AUX area
	 */
	void *(*setup_aux)		(int cpu, void **pages,
					 int nr_pages, bool overwrite);
					/* optional */

	/*
	 * Free pmu-private AUX data structures
	 */
	void (*free_aux)		(void *aux); /* optional */

	/*
	 * Validate address range filters: make sure the HW supports the
	 * requested configuration and number of filters; return 0 if the
	 * supplied filters are valid, -errno otherwise.
	 *
	 * Runs in the context of the ioctl()ing process and is not serialized
	 * with the rest of the PMU callbacks.
	 */
	int (*addr_filters_validate)	(struct list_head *filters);
					/* optional */

	/*
	 * Synchronize address range filter configuration:
	 * translate hw-agnostic filters into hardware configuration in
	 * event::hw::addr_filters.
	 *
	 * Runs as a part of filter sync sequence that is done in ->start()
	 * callback by calling perf_event_addr_filters_sync().
	 *
	 * May (and should) traverse event::addr_filters::list, for which its
	 * caller provides necessary serialization.
	 */
	void (*addr_filters_sync)	(struct perf_event *event);
					/* optional */

	/*
	 * Filter events for PMU-specific reasons.
	 */
	int (*filter_match)		(struct perf_event *event); /* optional */
};

/**
 * struct perf_addr_filter - address range filter definition
 * @entry:	event's filter list linkage
 * @inode:	object file's inode for file-based filters
 * @offset:	filter range offset
 * @size:	filter range size
 * @range:	1: range, 0: address
 * @filter:	1: filter/start, 0: stop
 *
 * This is a hardware-agnostic filter configuration as specified by the user.
 */
struct perf_addr_filter {
	struct list_head	entry;
	struct inode		*inode;
	unsigned long		offset;
	unsigned long		size;
	unsigned int		range	: 1,
				filter	: 1;
};

/**
 * struct perf_addr_filters_head - container for address range filters
 * @list:	list of filters for this event
 * @lock:	spinlock that serializes accesses to the @list and event's
 *		(and its children's) filter generations.
 *
 * A child event will use parent's @list (and therefore @lock), so they are
 * bundled together; see perf_event_addr_filters().
 */
struct perf_addr_filters_head {
	struct list_head	list;
	raw_spinlock_t		lock;
};

/**
 * enum perf_event_active_state - the states of a event
 */
enum perf_event_active_state {
	PERF_EVENT_STATE_DEAD		= -4,
	PERF_EVENT_STATE_EXIT		= -3,
	PERF_EVENT_STATE_ERROR		= -2,
	PERF_EVENT_STATE_OFF		= -1,
	PERF_EVENT_STATE_INACTIVE	=  0,
	PERF_EVENT_STATE_ACTIVE		=  1,
};

struct file;
struct perf_sample_data;

typedef void (*perf_overflow_handler_t)(struct perf_event *,
					struct perf_sample_data *,
					struct pt_regs *regs);

enum perf_group_flag {
	PERF_GROUP_SOFTWARE		= 0x1,
};

#define SWEVENT_HLIST_BITS		8
#define SWEVENT_HLIST_SIZE		(1 << SWEVENT_HLIST_BITS)

struct swevent_hlist {
	struct hlist_head		heads[SWEVENT_HLIST_SIZE];
	struct rcu_head			rcu_head;
};

#define PERF_ATTACH_CONTEXT	0x01
#define PERF_ATTACH_GROUP	0x02
#define PERF_ATTACH_TASK	0x04
#define PERF_ATTACH_TASK_DATA	0x08

struct perf_cgroup;
struct ring_buffer;

/**
 * struct perf_event - performance event kernel representation:
 */
struct perf_event {
#ifdef CONFIG_PERF_EVENTS
	/*
	 * entry onto perf_event_context::event_list;
	 *   modifications require ctx->lock
	 *   RCU safe iterations.
	 */
	struct list_head		event_entry;

	/*
	 * XXX: group_entry and sibling_list should be mutually exclusive;
	 * either you're a sibling on a group, or you're the group leader.
	 * Rework the code to always use the same list element.
	 *
	 * Locked for modification by both ctx->mutex and ctx->lock; holding
	 * either sufficies for read.
	 */
	struct list_head		group_entry;
	struct list_head		sibling_list;

	/*
	 * We need storage to track the entries in perf_pmu_migrate_context; we
	 * cannot use the event_entry because of RCU and we want to keep the
	 * group in tact which avoids us using the other two entries.
	 */
	struct list_head		migrate_entry;

	struct hlist_node		hlist_entry;
	struct list_head		active_entry;
	int				nr_siblings;
	int				group_flags;
	struct perf_event		*group_leader;
	struct pmu			*pmu;
	void				*pmu_private;

	enum perf_event_active_state	state;
	unsigned int			attach_state;
	local64_t			count;
	atomic64_t			child_count;

	/*
	 * These are the total time in nanoseconds that the event
	 * has been enabled (i.e. eligible to run, and the task has
	 * been scheduled in, if this is a per-task event)
	 * and running (scheduled onto the CPU), respectively.
	 *
	 * They are computed from tstamp_enabled, tstamp_running and
	 * tstamp_stopped when the event is in INACTIVE or ACTIVE state.
	 */
	u64				total_time_enabled;
	u64				total_time_running;

	/*
	 * These are timestamps used for computing total_time_enabled
	 * and total_time_running when the event is in INACTIVE or
	 * ACTIVE state, measured in nanoseconds from an arbitrary point
	 * in time.
	 * tstamp_enabled: the notional time when the event was enabled
	 * tstamp_running: the notional time when the event was scheduled on
	 * tstamp_stopped: in INACTIVE state, the notional time when the
	 *	event was scheduled off.
	 */
	u64				tstamp_enabled;
	u64				tstamp_running;
	u64				tstamp_stopped;

	/*
	 * timestamp shadows the actual context timing but it can
	 * be safely used in NMI interrupt context. It reflects the
	 * context time as it was when the event was last scheduled in.
	 *
	 * ctx_time already accounts for ctx->timestamp. Therefore to
	 * compute ctx_time for a sample, simply add perf_clock().
	 */
	u64				shadow_ctx_time;

	struct perf_event_attr		attr;
	u16				header_size;
	u16				id_header_size;
	u16				read_size;
	struct hw_perf_event		hw;

	struct perf_event_context	*ctx;
	atomic_long_t			refcount;

	/*
	 * These accumulate total time (in nanoseconds) that children
	 * events have been enabled and running, respectively.
	 */
	atomic64_t			child_total_time_enabled;
	atomic64_t			child_total_time_running;

	/*
	 * Protect attach/detach and child_list:
	 */
	struct mutex			child_mutex;
	struct list_head		child_list;
	struct perf_event		*parent;

	int				oncpu;
	int				cpu;

	struct list_head		owner_entry;
	struct task_struct		*owner;

	/* mmap bits */
	struct mutex			mmap_mutex;
	atomic_t			mmap_count;

	struct ring_buffer		*rb;
	struct list_head		rb_entry;
	unsigned long			rcu_batches;
	int				rcu_pending;

	/* poll related */
	wait_queue_head_t		waitq;
	struct fasync_struct		*fasync;

	/* delayed work for NMIs and such */
	int				pending_wakeup;
	int				pending_kill;
	int				pending_disable;
	struct irq_work			pending;

	atomic_t			event_limit;

	/* address range filters */
	struct perf_addr_filters_head	addr_filters;
	/* vma address array for file-based filders */
	unsigned long			*addr_filters_offs;
	unsigned long			addr_filters_gen;

	void (*destroy)(struct perf_event *);
	struct rcu_head			rcu_head;

	struct pid_namespace		*ns;
	u64				id;

	u64				(*clock)(void);
	perf_overflow_handler_t		overflow_handler;
	void				*overflow_handler_context;

#ifdef CONFIG_EVENT_TRACING
	struct trace_event_call		*tp_event;
	struct event_filter		*filter;
#ifdef CONFIG_FUNCTION_TRACER
	struct ftrace_ops               ftrace_ops;
#endif
#endif

#ifdef CONFIG_CGROUP_PERF
	struct perf_cgroup		*cgrp; /* cgroup event is attach to */
	int				cgrp_defer_enabled;
#endif

#endif /* CONFIG_PERF_EVENTS */
};

/**
 * struct perf_event_context - event context structure
 *
 * Used as a container for task events and CPU events as well:
 */
struct perf_event_context {
	struct pmu			*pmu;
	/*
	 * Protect the states of the events in the list,
	 * nr_active, and the list:
	 */
	raw_spinlock_t			lock;
	/*
	 * Protect the list of events.  Locking either mutex or lock
	 * is sufficient to ensure the list doesn't change; to change
	 * the list you need to lock both the mutex and the spinlock.
	 */
	struct mutex			mutex;

	struct list_head		active_ctx_list;
	struct list_head		pinned_groups;
	struct list_head		flexible_groups;
	struct list_head		event_list;
	int				nr_events;
	int				nr_active;
	int				is_active;
	int				nr_stat;
	int				nr_freq;
	int				rotate_disable;
	atomic_t			refcount;
	struct task_struct		*task;

	/*
	 * Context clock, runs when context enabled.
	 */
	u64				time;
	u64				timestamp;

	/*
	 * These fields let us detect when two contexts have both
	 * been cloned (inherited) from a common ancestor.
	 */
	struct perf_event_context	*parent_ctx;
	u64				parent_gen;
	u64				generation;
	int				pin_count;
	int				nr_cgroups;	 /* cgroup evts */
	void				*task_ctx_data; /* pmu specific data */
	struct rcu_head			rcu_head;
};

/*
 * Number of contexts where an event can trigger:
 *	task, softirq, hardirq, nmi.
 */
#define PERF_NR_CONTEXTS	4

/**
 * struct perf_event_cpu_context - per cpu event context structure
 */
struct perf_cpu_context {
	struct perf_event_context	ctx;
	struct perf_event_context	*task_ctx;
	int				active_oncpu;
	int				exclusive;

	raw_spinlock_t			hrtimer_lock;
	struct hrtimer			hrtimer;
	ktime_t				hrtimer_interval;
	unsigned int			hrtimer_active;

	struct pmu			*unique_pmu;
	struct perf_cgroup		*cgrp;
};

struct perf_output_handle {
	struct perf_event		*event;
	struct ring_buffer		*rb;
	unsigned long			wakeup;
	unsigned long			size;
	union {
		void			*addr;
		unsigned long		head;
	};
	int				page;
};

#ifdef CONFIG_CGROUP_PERF

/*
 * perf_cgroup_info keeps track of time_enabled for a cgroup.
 * This is a per-cpu dynamically allocated data structure.
 */
struct perf_cgroup_info {
	u64				time;
	u64				timestamp;
};

struct perf_cgroup {
	struct cgroup_subsys_state	css;
	struct perf_cgroup_info	__percpu *info;
};

/*
 * Must ensure cgroup is pinned (css_get) before calling
 * this function. In other words, we cannot call this function
 * if there is no cgroup event for the current CPU context.
 */
static inline struct perf_cgroup *
perf_cgroup_from_task(struct task_struct *task, struct perf_event_context *ctx)
{
	return container_of(task_css_check(task, perf_event_cgrp_id,
					   ctx ? lockdep_is_held(&ctx->lock)
					       : true),
			    struct perf_cgroup, css);
}
#endif /* CONFIG_CGROUP_PERF */

#ifdef CONFIG_PERF_EVENTS

extern void *perf_aux_output_begin(struct perf_output_handle *handle,
				   struct perf_event *event);
extern void perf_aux_output_end(struct perf_output_handle *handle,
				unsigned long size, bool truncated);
extern int perf_aux_output_skip(struct perf_output_handle *handle,
				unsigned long size);
extern void *perf_get_aux(struct perf_output_handle *handle);

extern int perf_pmu_register(struct pmu *pmu, const char *name, int type);
extern void perf_pmu_unregister(struct pmu *pmu);

extern int perf_num_counters(void);
extern const char *perf_pmu_name(void);
extern void __perf_event_task_sched_in(struct task_struct *prev,
				       struct task_struct *task);
extern void __perf_event_task_sched_out(struct task_struct *prev,
					struct task_struct *next);
extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
extern void perf_event_delayed_put(struct task_struct *task);
extern struct file *perf_event_get(unsigned int fd);
extern const struct perf_event_attr *perf_event_attrs(struct perf_event *event);
extern void perf_event_print_debug(void);
extern void perf_pmu_disable(struct pmu *pmu);
extern void perf_pmu_enable(struct pmu *pmu);
extern void perf_sched_cb_dec(struct pmu *pmu);
extern void perf_sched_cb_inc(struct pmu *pmu);
extern int perf_event_task_disable(void);
extern int perf_event_task_enable(void);
extern int perf_event_refresh(struct perf_event *event, int refresh);
extern void perf_event_update_userpage(struct perf_event *event);
extern int perf_event_release_kernel(struct perf_event *event);
extern struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr,
				int cpu,
				struct task_struct *task,
				perf_overflow_handler_t callback,
				void *context);
extern void perf_pmu_migrate_context(struct pmu *pmu,
				int src_cpu, int dst_cpu);
extern u64 perf_event_read_local(struct perf_event *event);
extern u64 perf_event_read_value(struct perf_event *event,
				 u64 *enabled, u64 *running);


struct perf_sample_data {
	/*
	 * Fields set by perf_sample_data_init(), group so as to
	 * minimize the cachelines touched.
	 */
	u64				addr;
	struct perf_raw_record		*raw;
	struct perf_branch_stack	*br_stack;
	u64				period;
	u64				weight;
	u64				txn;
	union  perf_mem_data_src	data_src;

	/*
	 * The other fields, optionally {set,used} by
	 * perf_{prepare,output}_sample().
	 */
	u64				type;
	u64				ip;
	struct {
		u32	pid;
		u32	tid;
	}				tid_entry;
	u64				time;
	u64				id;
	u64				stream_id;
	struct {
		u32	cpu;
		u32	reserved;
	}				cpu_entry;
	struct perf_callchain_entry	*callchain;

	/*
	 * regs_user may point to task_pt_regs or to regs_user_copy, depending
	 * on arch details.
	 */
	struct perf_regs		regs_user;
	struct pt_regs			regs_user_copy;

	struct perf_regs		regs_intr;
	u64				stack_user_size;
} ____cacheline_aligned;

/* default value for data source */
#define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
		    PERF_MEM_S(LVL, NA)   |\
		    PERF_MEM_S(SNOOP, NA) |\
		    PERF_MEM_S(LOCK, NA)  |\
		    PERF_MEM_S(TLB, NA))

static inline void perf_sample_data_init(struct perf_sample_data *data,
					 u64 addr, u64 period)
{
	/* remaining struct members initialized in perf_prepare_sample() */
	data->addr = addr;
	data->raw  = NULL;
	data->br_stack = NULL;
	data->period = period;
	data->weight = 0;
	data->data_src.val = PERF_MEM_NA;
	data->txn = 0;
}

extern void perf_output_sample(struct perf_output_handle *handle,
			       struct perf_event_header *header,
			       struct perf_sample_data *data,
			       struct perf_event *event);
extern void perf_prepare_sample(struct perf_event_header *header,
				struct perf_sample_data *data,
				struct perf_event *event,
				struct pt_regs *regs);

extern int perf_event_overflow(struct perf_event *event,
				 struct perf_sample_data *data,
				 struct pt_regs *regs);

extern void perf_event_output_forward(struct perf_event *event,
				     struct perf_sample_data *data,
				     struct pt_regs *regs);
extern void perf_event_output_backward(struct perf_event *event,
				       struct perf_sample_data *data,
				       struct pt_regs *regs);
extern void perf_event_output(struct perf_event *event,
			      struct perf_sample_data *data,
			      struct pt_regs *regs);

static inline bool
is_default_overflow_handler(struct perf_event *event)
{
	if (likely(event->overflow_handler == perf_event_output_forward))
		return true;
	if (unlikely(event->overflow_handler == perf_event_output_backward))
		return true;
	return false;
}

extern void
perf_event_header__init_id(struct perf_event_header *header,
			   struct perf_sample_data *data,
			   struct perf_event *event);
extern void
perf_event__output_id_sample(struct perf_event *event,
			     struct perf_output_handle *handle,
			     struct perf_sample_data *sample);

extern void
perf_log_lost_samples(struct perf_event *event, u64 lost);

static inline bool is_sampling_event(struct perf_event *event)
{
	return event->attr.sample_period != 0;
}

/*
 * Return 1 for a software event, 0 for a hardware event
 */
static inline int is_software_event(struct perf_event *event)
{
	return event->pmu->task_ctx_nr == perf_sw_context;
}

extern struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];

extern void ___perf_sw_event(u32, u64, struct pt_regs *, u64);
extern void __perf_sw_event(u32, u64, struct pt_regs *, u64);

#ifndef perf_arch_fetch_caller_regs
static inline void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip) { }
#endif

/*
 * Take a snapshot of the regs. Skip ip and frame pointer to
 * the nth caller. We only need a few of the regs:
 * - ip for PERF_SAMPLE_IP
 * - cs for user_mode() tests
 * - bp for callchains
 * - eflags, for future purposes, just in case
 */
static inline void perf_fetch_caller_regs(struct pt_regs *regs)
{
	memset(regs, 0, sizeof(*regs));

	perf_arch_fetch_caller_regs(regs, CALLER_ADDR0);
}

static __always_inline void
perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
	if (static_key_false(&perf_swevent_enabled[event_id]))
		__perf_sw_event(event_id, nr, regs, addr);
}

DECLARE_PER_CPU(struct pt_regs, __perf_regs[4]);

/*
 * 'Special' version for the scheduler, it hard assumes no recursion,
 * which is guaranteed by us not actually scheduling inside other swevents
 * because those disable preemption.
 */
static __always_inline void
perf_sw_event_sched(u32 event_id, u64 nr, u64 addr)
{
	if (static_key_false(&perf_swevent_enabled[event_id])) {
		struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]);

		perf_fetch_caller_regs(regs);
		___perf_sw_event(event_id, nr, regs, addr);
	}
}

extern struct static_key_false perf_sched_events;

static __always_inline bool
perf_sw_migrate_enabled(void)
{
	if (static_key_false(&perf_swevent_enabled[PERF_COUNT_SW_CPU_MIGRATIONS]))
		return true;
	return false;
}

static inline void perf_event_task_migrate(struct task_struct *task)
{
	if (perf_sw_migrate_enabled())
		task->sched_migrated = 1;
}

static inline void perf_event_task_sched_in(struct task_struct *prev,
					    struct task_struct *task)
{
	if (static_branch_unlikely(&perf_sched_events))
		__perf_event_task_sched_in(prev, task);

	if (perf_sw_migrate_enabled() && task->sched_migrated) {
		struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]);

		perf_fetch_caller_regs(regs);
		___perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, regs, 0);
		task->sched_migrated = 0;
	}
}

static inline void perf_event_task_sched_out(struct task_struct *prev,
					     struct task_struct *next)
{
	perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0);

	if (static_branch_unlikely(&perf_sched_events))
		__perf_event_task_sched_out(prev, next);
}

static inline u64 __perf_event_count(struct perf_event *event)
{
	return local64_read(&event->count) + atomic64_read(&event->child_count);
}

extern void perf_event_mmap(struct vm_area_struct *vma);
extern struct perf_guest_info_callbacks *perf_guest_cbs;
extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);

extern void perf_event_exec(void);
extern void perf_event_comm(struct task_struct *tsk, bool exec);
extern void perf_event_fork(struct task_struct *tsk);

/* Callchains */
DECLARE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);

extern void perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs);
extern void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs);
extern struct perf_callchain_entry *
get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user,
		   bool crosstask, bool add_mark);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);

extern int sysctl_perf_event_max_stack;

static inline int perf_callchain_store(struct perf_callchain_entry *entry, u64 ip)
{
	if (entry->nr < sysctl_perf_event_max_stack) {
		entry->ip[entry->nr++] = ip;
		return 0;
	} else {
		return -1; /* no more room, stop walking the stack */
	}
}

extern int sysctl_perf_event_paranoid;
extern int sysctl_perf_event_mlock;
extern int sysctl_perf_event_sample_rate;
extern int sysctl_perf_cpu_time_max_percent;

extern void perf_sample_event_took(u64 sample_len_ns);

extern int perf_proc_update_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos);
extern int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos);

int perf_event_max_stack_handler(struct ctl_table *table, int write,
				 void __user *buffer, size_t *lenp, loff_t *ppos);

static inline bool perf_paranoid_tracepoint_raw(void)
{
	return sysctl_perf_event_paranoid > -1;
}

static inline bool perf_paranoid_cpu(void)
{
	return sysctl_perf_event_paranoid > 0;
}

static inline bool perf_paranoid_kernel(void)
{
	return sysctl_perf_event_paranoid > 1;
}

extern void perf_event_init(void);
extern void perf_tp_event(u64 addr, u64 count, void *record,
			  int entry_size, struct pt_regs *regs,
			  struct hlist_head *head, int rctx,
			  struct task_struct *task);
extern void perf_bp_event(struct perf_event *event, void *data);

#ifndef perf_misc_flags
# define perf_misc_flags(regs) \
		(user_mode(regs) ? PERF_RECORD_MISC_USER : PERF_RECORD_MISC_KERNEL)
# define perf_instruction_pointer(regs)	instruction_pointer(regs)
#endif

static inline bool has_branch_stack(struct perf_event *event)
{
	return event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK;
}

static inline bool needs_branch_stack(struct perf_event *event)
{
	return event->attr.branch_sample_type != 0;
}

static inline bool has_aux(struct perf_event *event)
{
	return event->pmu->setup_aux;
}

static inline bool is_write_backward(struct perf_event *event)
{
	return !!event->attr.write_backward;
}

static inline bool has_addr_filter(struct perf_event *event)
{
	return event->pmu->nr_addr_filters;
}

/*
 * An inherited event uses parent's filters
 */
static inline struct perf_addr_filters_head *
perf_event_addr_filters(struct perf_event *event)
{
	struct perf_addr_filters_head *ifh = &event->addr_filters;

	if (event->parent)
		ifh = &event->parent->addr_filters;

	return ifh;
}

extern void perf_event_addr_filters_sync(struct perf_event *event);

extern int perf_output_begin(struct perf_output_handle *handle,
			     struct perf_event *event, unsigned int size);
extern int perf_output_begin_forward(struct perf_output_handle *handle,
				    struct perf_event *event,
				    unsigned int size);
extern int perf_output_begin_backward(struct perf_output_handle *handle,
				      struct perf_event *event,
				      unsigned int size);

extern void perf_output_end(struct perf_output_handle *handle);
extern unsigned int perf_output_copy(struct perf_output_handle *handle,
			     const void *buf, unsigned int len);
extern unsigned int perf_output_skip(struct perf_output_handle *handle,
				     unsigned int len);
extern int perf_swevent_get_recursion_context(void);
extern void perf_swevent_put_recursion_context(int rctx);
extern u64 perf_swevent_set_period(struct perf_event *event);
extern void perf_event_enable(struct perf_event *event);
extern void perf_event_disable(struct perf_event *event);
extern void perf_event_disable_local(struct perf_event *event);
extern void perf_event_task_tick(void);
#else /* !CONFIG_PERF_EVENTS: */
static inline void *
perf_aux_output_begin(struct perf_output_handle *handle,
		      struct perf_event *event)				{ return NULL; }
static inline void
perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
		    bool truncated)					{ }
static inline int
perf_aux_output_skip(struct perf_output_handle *handle,
		     unsigned long size)				{ return -EINVAL; }
static inline void *
perf_get_aux(struct perf_output_handle *handle)				{ return NULL; }
static inline void
perf_event_task_migrate(struct task_struct *task)			{ }
static inline void
perf_event_task_sched_in(struct task_struct *prev,
			 struct task_struct *task)			{ }
static inline void
perf_event_task_sched_out(struct task_struct *prev,
			  struct task_struct *next)			{ }
static inline int perf_event_init_task(struct task_struct *child)	{ return 0; }
static inline void perf_event_exit_task(struct task_struct *child)	{ }
static inline void perf_event_free_task(struct task_struct *task)	{ }
static inline void perf_event_delayed_put(struct task_struct *task)	{ }
static inline struct file *perf_event_get(unsigned int fd)	{ return ERR_PTR(-EINVAL); }
static inline const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
{
	return ERR_PTR(-EINVAL);
}
static inline u64 perf_event_read_local(struct perf_event *event)	{ return -EINVAL; }
static inline void perf_event_print_debug(void)				{ }
static inline int perf_event_task_disable(void)				{ return -EINVAL; }
static inline int perf_event_task_enable(void)				{ return -EINVAL; }
static inline int perf_event_refresh(struct perf_event *event, int refresh)
{
	return -EINVAL;
}

static inline void
perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)	{ }
static inline void
perf_sw_event_sched(u32 event_id, u64 nr, u64 addr)			{ }
static inline void
perf_bp_event(struct perf_event *event, void *data)			{ }

static inline int perf_register_guest_info_callbacks
(struct perf_guest_info_callbacks *callbacks)				{ return 0; }
static inline int perf_unregister_guest_info_callbacks
(struct perf_guest_info_callbacks *callbacks)				{ return 0; }

static inline void perf_event_mmap(struct vm_area_struct *vma)		{ }
static inline void perf_event_exec(void)				{ }
static inline void perf_event_comm(struct task_struct *tsk, bool exec)	{ }
static inline void perf_event_fork(struct task_struct *tsk)		{ }
static inline void perf_event_init(void)				{ }
static inline int  perf_swevent_get_recursion_context(void)		{ return -1; }
static inline void perf_swevent_put_recursion_context(int rctx)		{ }
static inline u64 perf_swevent_set_period(struct perf_event *event)	{ return 0; }
static inline void perf_event_enable(struct perf_event *event)		{ }
static inline void perf_event_disable(struct perf_event *event)		{ }
static inline int __perf_event_disable(void *info)			{ return -1; }
static inline void perf_event_task_tick(void)				{ }
static inline int perf_event_release_kernel(struct perf_event *event)	{ return 0; }
#endif

#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
extern void perf_restore_debug_store(void);
#else
static inline void perf_restore_debug_store(void)			{ }
#endif

#define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x))

/*
 * This has to have a higher priority than migration_notifier in sched/core.c.
 */
#define perf_cpu_notifier(fn)						\
do {									\
	static struct notifier_block fn##_nb =				\
		{ .notifier_call = fn, .priority = CPU_PRI_PERF };	\
	unsigned long cpu = smp_processor_id();				\
	unsigned long flags;						\
									\
	cpu_notifier_register_begin();					\
	fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE,			\
		(void *)(unsigned long)cpu);				\
	local_irq_save(flags);						\
	fn(&fn##_nb, (unsigned long)CPU_STARTING,			\
		(void *)(unsigned long)cpu);				\
	local_irq_restore(flags);					\
	fn(&fn##_nb, (unsigned long)CPU_ONLINE,				\
		(void *)(unsigned long)cpu);				\
	__register_cpu_notifier(&fn##_nb);				\
	cpu_notifier_register_done();					\
} while (0)

/*
 * Bare-bones version of perf_cpu_notifier(), which doesn't invoke the
 * callback for already online CPUs.
 */
#define __perf_cpu_notifier(fn)						\
do {									\
	static struct notifier_block fn##_nb =				\
		{ .notifier_call = fn, .priority = CPU_PRI_PERF };	\
									\
	__register_cpu_notifier(&fn##_nb);				\
} while (0)

struct perf_pmu_events_attr {
	struct device_attribute attr;
	u64 id;
	const char *event_str;
};

ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
			      char *page);

#define PMU_EVENT_ATTR(_name, _var, _id, _show)				\
static struct perf_pmu_events_attr _var = {				\
	.attr = __ATTR(_name, 0444, _show, NULL),			\
	.id   =  _id,							\
};

#define PMU_EVENT_ATTR_STRING(_name, _var, _str)			    \
static struct perf_pmu_events_attr _var = {				    \
	.attr		= __ATTR(_name, 0444, perf_event_sysfs_show, NULL), \
	.id		= 0,						    \
	.event_str	= _str,						    \
};

#define PMU_FORMAT_ATTR(_name, _format)					\
static ssize_t								\
_name##_show(struct device *dev,					\
			       struct device_attribute *attr,		\
			       char *page)				\
{									\
	BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE);			\
	return sprintf(page, _format "\n");				\
}									\
									\
static struct device_attribute format_attr_##_name = __ATTR_RO(_name)

#endif /* _LINUX_PERF_EVENT_H */