Provided by: freebsd-manpages_8.2-1_all bug

NAME

     vm_page_io_start, vm_page_io_finish — ready or unready a page for I/O

SYNOPSIS

     #include <sys/param.h>
     #include <vm/vm.h>
     #include <vm/vm_page.h>

     void
     vm_page_io_start(vm_page_t m);

     void
     vm_page_io_finish(vm_page_t m);

DESCRIPTION

     The vm_page_io_start() function prepares the page for I/O by incrementing its busy flag by
     one.

     The vm_page_io_finish() function lowers the busy count on the page by one, if the resulting
     busy count is zero, a wakeup(9) will be issued if the page has been marked VPO_WANTED.  A
     page is typically marked VPO_WANTED by a thread to register its interest in the page to
     either complete I/O or becoming available for general use.

AUTHORS

     This manual page was written by Chad David <davidc@acns.ab.ca> and Alfred Perlstein
     <alfred@FreeBSD.org>.