mincore - determine whether pages are resident in memory
int mincore(void *
length, unsigned char
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
mincore(): Since glibc 2.19: _DEFAULT_SOURCE Glibc 2.19 and earlier: _BSD_SOURCE || _SVID_SOURCE
mincore() returns a vector that indicates whether
pages of the calling process's virtual memory are resident in core
(RAM), and so will not cause a disk access (page fault) if referenced.
The kernel returns residency information about the pages starting at the
addr, and continuing for
addr argument must be a multiple of the system page
length argument need not be a multiple of the page
size, but since residency information is returned for whole pages,
length is effectively rounded up to the next multiple of the
page size. One may obtain the page size (PAGE_SIZE)
vec argument must point to an array containing at least
(length+PAGE_SIZE-1) / PAGE_SIZE bytes. On return, the least
significant bit of each byte will be set if the corresponding page is
currently resident in memory, and be clear otherwise. (The settings of
the other bits in each byte are undefined; these bits are reserved for
possible later use.) Of course the information returned in
is only a snapshot: pages that are not locked in memory can come and go
at any moment, and the contents of
vec may already be stale by
the time this call returns.
On success, mincore() returns zero. On error, -1 is
errno is set appropriately.
EAGAIN kernel is temporarily out of resources.
vec points to an invalid address.
addr is not a multiple of the page size.
length is greater than (
(This could occur if a negative value is specified for
since that value will be interpreted as a large unsigned integer.) In
Linux 2.6.11 and earlier, the error EINVAL was returned
for this condition.
length contained unmapped
Available since Linux 2.3.99pre1 and glibc 2.2.
Before kernel 2.6.21, mincore() did not return correct information for MAP_PRIVATE mappings, or for nonlinear mappings (established using remap_file_pages(2)).
fincore(1), madvise(2), mlock(2), mmap(2), posix_fadvise(2), posix_madvise(3)
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