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28 .\" @(#)mincore.2 8.1 (Berkeley) 6/9/93
35 .Nd determine residency of memory pages
41 .Fn mincore "const void *addr" "size_t len" "char *vec"
45 system call determines whether each of the pages in the region beginning at
49 bytes is resident or mapped, depending on the value of sysctl
50 .Va vm.mincore_mapped .
51 .\"The beginning address,
53 .\"is first rounded down to a multiple of the page size (see
54 .\".Xr getpagesize 3 ) .
56 .\".Fa addr No + Fa len ,
57 .\"is rounded up to a multiple of the page size.
58 The status is returned in the
60 array, one character per page.
61 Each character is either 0 if the page is not resident, or a combination of
62 the following flags (defined in
64 .Bl -tag -width ".Dv MINCORE_REFERENCED_OTHER"
66 Page is in core (resident).
67 .It Dv MINCORE_REFERENCED
68 Page has been referenced by us.
69 .It Dv MINCORE_MODIFIED
70 Page has been modified by us.
71 .It Dv MINCORE_REFERENCED_OTHER
72 Page has been referenced.
73 .It Dv MINCORE_MODIFIED_OTHER
74 Page has been modified.
75 .It Dv MINCORE_PSIND(i)
76 Page is part of a large
78 page with size given by index
80 in the array returned by
86 If any bits in this mask are set, the page is part of a large
91 The information returned by
93 may be out of date by the time the system call returns.
94 The only way to ensure that a page is resident is to lock it into memory
100 .Va vm.mincore_mapped
101 sysctl is set to a non-zero value (default), only the current process'
102 mappings of the pages in the specified virtual address range are examined.
103 This does not preclude the system from returning
104 .Dv MINCORE_REFERENCED_OTHER
106 .Dv MINCORE_MODIFIED_OTHER
108 Otherwise, if the sysctl value is zero, all resident pages backing the
109 specified address range are examined, regardless of the mapping state.
110 .Sh IMPLEMENTATION NOTES
111 Prior to the introduction of
116 consisted of a single bit equal to
117 .Dv MINCORE_PSIND(1) .
118 In particular, applications compiled using the old value of
120 will not identify large pages with size index 2 as being large pages.
126 system call will fail if:
129 The virtual address range specified by the
133 arguments is not fully mapped.
137 argument points to an illegal address.
150 system call first appeared in