1		i	synthesize instructions events
2		b	synthesize branches events (branch misses for Arm SPE)
3		c	synthesize branches events (calls only)
4		r	synthesize branches events (returns only)
5		x	synthesize transactions events
6		w	synthesize ptwrite events
7		p	synthesize power events
8		o	synthesize other events recorded due to the use
9			of aux-output (refer to perf record)
10		e	synthesize error events
11		d	create a debug log
12		f	synthesize first level cache events
13		m	synthesize last level cache events
14		t	synthesize TLB events
15		a	synthesize remote access events
16		g	synthesize a call chain (use with i or x)
17		G	synthesize a call chain on existing event records
18		l	synthesize last branch entries (use with i or x)
19		L	synthesize last branch entries on existing event records
20		s       skip initial number of events
21
22	The default is all events i.e. the same as --itrace=ibxwpe,
23	except for perf script where it is --itrace=ce
24
25	In addition, the period (default 100000, except for perf script where it is 1)
26	for instructions events can be specified in units of:
27
28		i	instructions
29		t	ticks
30		ms	milliseconds
31		us	microseconds
32		ns	nanoseconds (default)
33
34	Also the call chain size (default 16, max. 1024) for instructions or
35	transactions events can be specified.
36
37	Also the number of last branch entries (default 64, max. 1024) for
38	instructions or transactions events can be specified.
39
40	Similar to options g and l, size may also be specified for options G and L.
41	On x86, note that G and L work poorly when data has been recorded with
42	large PEBS. Refer linkperf:perf-intel-pt[1] man page for details.
43
44	It is also possible to skip events generated (instructions, branches, transactions,
45	ptwrite, power) at the beginning. This is useful to ignore initialization code.
46
47	--itrace=i0nss1000000
48
49	skips the first million instructions.
50