[unix-history] / usr / man / man2 / profil.2

.TH PROFIL 2 "12 February 1983"
.UC 4
.SH NAME
profil \- execution time profile
.SH SYNOPSIS
.nf
.B profil(buff, bufsiz, offset, scale)
.B char *buff;
.B int bufsiz, offset, scale;
.fi
.SH DESCRIPTION
.I Buff
points to an area of core whose length (in bytes) is given by
.IR bufsiz .
After this call, the user's program counter (pc)
is examined each clock tick (10 milliseconds);
.I offset
is subtracted from it, and the result multiplied by
.IR scale .
If the resulting number corresponds to a word
inside
.I buff,
that word is incremented.
.PP
The scale is interpreted as an unsigned,
fixed-point fraction with binary point at the
left: 0x10000 gives a 1-1 mapping of pc's to words
in
.I buff;
0x8000 maps each pair of instruction words
together.
0x2 maps all instructions onto the beginning of
.I buff
(producing a non-interrupting core clock).
.PP
Profiling is turned off by giving a
.I scale
of 0 or 1.
It is rendered
ineffective by giving a
.I bufsiz
of 0.
Profiling is turned off when an
.I execve
is executed, but remains on in child and parent both
after a
.IR fork .
Profiling is turned off if an update in
.I buff
would cause a memory fault.
.SH "RETURN VALUE
A 0, indicating success, is always returned.
.SH "SEE ALSO"
gprof(1), setitimer(2), monitor(3)
Commit	Line	Data
9963d26a C	1	.TH PROFIL 2 "12 February 1983"
	2	.UC 4
	3	.SH NAME
	4	profil \- execution time profile
	5	.SH SYNOPSIS
	6	.nf
	7	.B profil(buff, bufsiz, offset, scale)
	8	.B char *buff;
	9	.B int bufsiz, offset, scale;
	10	.fi
	11	.SH DESCRIPTION
	12	.I Buff
	13	points to an area of core whose length (in bytes) is given by
	14	.IR bufsiz .
	15	After this call, the user's program counter (pc)
	16	is examined each clock tick (10 milliseconds);
	17	.I offset
	18	is subtracted from it, and the result multiplied by
	19	.IR scale .
	20	If the resulting number corresponds to a word
	21	inside
	22	.I buff,
	23	that word is incremented.
	24	.PP
	25	The scale is interpreted as an unsigned,
	26	fixed-point fraction with binary point at the
	27	left: 0x10000 gives a 1-1 mapping of pc's to words
	28	in
	29	.I buff;
	30	0x8000 maps each pair of instruction words
	31	together.
	32	0x2 maps all instructions onto the beginning of
	33	.I buff
	34	(producing a non-interrupting core clock).
	35	.PP
	36	Profiling is turned off by giving a
	37	.I scale
	38	of 0 or 1.
	39	It is rendered
	40	ineffective by giving a
	41	.I bufsiz
	42	of 0.
	43	Profiling is turned off when an
	44	.I execve
	45	is executed, but remains on in child and parent both
	46	after a
	47	.IR fork .
	48	Profiling is turned off if an update in
	49	.I buff
	50	would cause a memory fault.
	51	.SH "RETURN VALUE
	52	A 0, indicating success, is always returned.
	53	.SH "SEE ALSO"
	54	gprof(1), setitimer(2), monitor(3)