pmap_page_exists_quick.9

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.Dd July 21, 2003
.Dt PMAP_PAGE_EXISTS_QUICK 9
.Os
.Sh NAME
.Nm pmap_page_exists_quick
.Nd determine if a page exists in a physical map
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
.In vm/pmap.h
.Ft bool
.Fn pmap_page_exists_quick "pmap_t pmap" "vm_page_t m"
.Sh DESCRIPTION
The
.Fn pmap_page_exists_quick
function is used to quickly determine if the page
.Fa m
exists in the physical map
.Fa pmap .
It is typically called from the VM paging code.
.Sh IMPLEMENTATION NOTES
The PV count used above may be changed upwards or downwards in future;
it is only necessary that
.Dv true
be returned for a small subset of pmaps for proper page aging.
.Sh RETURN VALUES
The
.Fn pmap_page_exists_quick
returns
.Dv true
only if the PV entry for the physical map
.Fa pmap
is one of the first 16 PVs linked from the page
.Fa m .
.Sh SEE ALSO
.Xr pmap 9
.Sh AUTHORS
This manual page was written by
.An Bruce M Simpson Aq Mt bms@spc.org .