Kernel Functions for Drivers                             btop(9F)



NAME
     btop - convert size in bytes to size in pages (round down)

SYNOPSIS
     #include 



     unsigned long btop(unsigned long numbytes);


INTERFACE LEVEL
     Architecture independent level 1 (DI/DKI).

PARAMETERS
     numbytes    Number of bytes.


DESCRIPTION
     The btop() function returns the number of memory pages  that
     are  contained  in the specified number of bytes, with down-
     ward rounding in the case that the byte count is not a  page
     multiple.  For  example,  if  the  page  size  is 2048, then
     btop(4096) returns 2, and  btop(4097)  returns  2  as  well.
     btop(0) returns 0.

RETURN VALUES
     The return value is always the number of pages. There are no
     invalid input values, and therefore no error return values.

CONTEXT
     The btop() function can be called from user,  interrupt,  or
     kernel context.

SEE ALSO
     btopr(9F), ddibtop(9F), ptob(9F)


     Writing Device Drivers
















SunOS 5.11          Last change: 16 Jan 2006                    1