1PROFIL(2)                     System Calls Manual                    PROFIL(2)
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NAME

6       profil - execution time profile
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SYNOPSIS

9       profil(buff, bufsiz, offset, scale)
10       char *buff;
11       int bufsiz, offset, scale;
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DESCRIPTION

14       Buff points to an area of core whose length (in bytes) is given by buf‐
15       siz.  After this call, the user's program counter (pc) is examined each
16       clock  tick (60th second); offset is subtracted from it, and the result
17       multiplied by scale.  If the resulting number  corresponds  to  a  word
18       inside buff, that word is incremented.
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20       The  scale  is  interpreted  as  an unsigned, fixed-point fraction with
21       binary point at the left: 0177777(8) gives a 1-1  mapping  of  pc's  to
22       words  in buff; 077777(8) maps each pair of instruction words together.
23       02(8) maps all instructions onto the beginning  of  buff  (producing  a
24       non-interrupting core clock).
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26       Profiling  is  turned  off by giving a scale of 0 or 1.  It is rendered
27       ineffective by giving a bufsiz of 0.  Profiling is turned off  when  an
28       exec is executed, but remains on in child and parent both after a fork.
29       Profiling may be turned off if an update in buff would cause  a  memory
30       fault.
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SEE ALSO

33       monitor(3), prof(1)
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ASSEMBLER

36       (profil = 44.)
37       sys profil; buff; bufsiz; offset; scale
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