Manpage of MINCORE
MINCORESection: Linux Programmer's Manual (2)
NAMEmincore - determine whether pages are resident in memory
int mincore(void *addr, size_t length, unsigned char *vec);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
DESCRIPTIONmincore() 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 address addr, and continuing for lengthbytes.
The addrargument must be a multiple of the system page size. The lengthargument need not be a multiple of the page size, but since residency information is returned for whole pages, lengthis effectively rounded up to themultiple of the page size. One may obtain the page size (PAGE_SIZE) using sysconf(_SC_PAGESIZE).
The vecargument must point to an array containing at least (length+PAGE_SIZE-1) / PAGE_SIZEbytes. 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 vecis only a snapshot: pages that are not locked in memory can come and go at any moment, and theof vecmay already be stale by the time this call returns.
RETURN VALUEOn success, mincore() returns zero. On error, -1 is returned, and errnois set appropriately.
ERRORSEAGAINkernel is temporarily out of resources.
- vecpoints to an invalid address.
- addris not a multiple of the page size.
- lengthis greater than (TASK_SIZE - addr). (This could occur if a negative value is specified for length, since that value will be interpreted as a large unsigned integer.) In Linux 2.6.11 and earlier, the error EINVALwas returned for this condition.
- addrto addr+ lengthcontained unmapped memory.
VERSIONSAvailable since Linux 2.3.99pre1 and glibc 2.2.
CONFORMING TOmincore() is not specified in POSIX.1, and it is not available on all UNIX implementations.
BUGSBefore kernel 2.6.21, mincore() did not return correct information for MAP_PRIVATEmappings, or for nonlinear mappings (established using remap_file_pages(2)).
SEE ALSOmadvise(2), mlock(2), mmap(2), posix_fadvise(2), posix_madvise(3)
This document was created by man2html, using the manual pages.
Time: 16:30:10 GMT, March 14, 2017 Click Here!