xref: /freebsd/share/man/man9/vm_fault_prefault.9 (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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26.\" $FreeBSD$
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28.Dd July 21, 2003
29.Dt VM_FAULT_PREFAULT 9
30.Os
31.Sh NAME
32.Nm vm_fault_prefault
33.Nd cluster page faults into a process's address space
34.Sh SYNOPSIS
35.In sys/param.h
36.In vm/vm.h
37.In vm/pmap.h
38.Ft void
39.Fn vm_fault_prefault "pmap_t pmap" "vm_offset_t addra" "vm_map_entry_t entry"
40.Sh DESCRIPTION
41The
42.Fn vm_fault_prefault
43function provides a means of clustering pagefaults into a process's
44address space.
45It operates upon the physical map
46.Fa pmap .
47The
48.Fa entry
49argument specifies the entry to be prefaulted; the
50.Fa addra
51argument specifies the beginning of the mapping in the process's virtual
52address space.
53.Pp
54It is typically called by
55.Fn vm_fault
56after the first page fault.
57It benefits the
58.Xr execve 2
59system call by eliminating repetitive calls to
60.Fn vm_fault ,
61which would otherwise be made to bring the process's executable pages
62into physical memory.
63.Sh IMPLEMENTATION NOTES
64This is a machine-independent function which calls the machine-dependent
65.Xr pmap_is_prefaultable 9
66helper function to determine if a page may be prefaulted into physical memory.
67.Sh SEE ALSO
68.Xr execve 2 ,
69.Xr pmap_is_prefaultable 9
70.Sh AUTHORS
71This manual page was written by
72.An Bruce M Simpson Aq Mt bms@spc.org .
73