usr/share/man/cat2/profil.0

PROFIL(2)                   BSD Programmer's Manual                  PROFIL(2)

N\bNA\bAM\bME\bE
     p\bpr\bro\bof\bfi\bil\bl - control process profiling

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     _\bi_\bn_\bt
     p\bpr\bro\bof\bfi\bil\bl(_\bc_\bh_\ba_\br _\b*_\bs_\ba_\bm_\bp_\bl_\be_\bs, _\bi_\bn_\bt _\bs_\bi_\bz_\be, _\bi_\bn_\bt _\bo_\bf_\bf_\bs_\be_\bt, _\bi_\bn_\bt _\bs_\bc_\ba_\bl_\be);

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     The p\bpr\bro\bof\bfi\bil\bl() function enables or disables program counter profiling of
     the current process.  If profiling is enabled, then at every clock tick,
     the kernel updates an appropriate count in the _\bs_\ba_\bm_\bp_\bl_\be_\bs buffer.

     The buffer _\bs_\ba_\bm_\bp_\bl_\be_\bs contains _\bs_\bi_\bz_\be bytes and is divided into a series of
     16-bit bins.  Each bin counts the number of times the program counter was
     in a particular address range in the process when a clock tick occurred
     while profiling was enabled.  For a given program counter address, the
     number of the corresponding bin is given by the relation:

           [(pc - offset) / 2] * scale / 65536

     The _\bo_\bf_\bf_\bs_\be_\bt parameter is the lowest address at which the kernel takes pro-
     gram counter samples.  The _\bs_\bc_\ba_\bl_\be parameter ranges from 1 to 65536 and can
     be used to change the span of the bins.  A scale of 65536 maps each bin
     to 2 bytes of address range; a scale of 32768 gives 4 bytes, 16384 gives
     8 bytes and so on.  Intermediate values provide approximate intermediate
     ranges.  A _\bs_\bc_\ba_\bl_\be value of 0 disables profiling.

R\bRE\bET\bTU\bUR\bRN\bN V\bVA\bAL\bLU\bUE\bES\bS
     If the _\bs_\bc_\ba_\bl_\be value is nonzero and the buffer _\bs_\ba_\bm_\bp_\bl_\be_\bs contains an illegal
     address, p\bpr\bro\bof\bfi\bil\bl() returns -1, profiling is terminated and _\be_\br_\br_\bn_\bo is set
     appropriately.  Otherwise p\bpr\bro\bof\bfi\bil\bl() returns 0.

F\bFI\bIL\bLE\bES\bS
     /usr/lib/gcrt0.o  profiling C run-time startup file
     gmon.out          conventional name for profiling output file

E\bER\bRR\bRO\bOR\bRS\bS
     The following error may be reported:

     [EFAULT]      The buffer _\bs_\ba_\bm_\bp_\bl_\be_\bs contains an invalid address.

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     gprof(1)

B\bBU\bUG\bGS\bS
     This routine should be named p\bpr\bro\bof\bfi\bil\ble\be().

     The _\bs_\ba_\bm_\bp_\bl_\be_\bs argument should really be a vector of type _\bu_\bn_\bs_\bi_\bg_\bn_\be_\bd _\bs_\bh_\bo_\br_\bt.

     The format of the gmon.out file is undocumented.

4.4BSD                           June 4, 1993                                1