CentOS 7.0 - man page for mincore (centos section 2)

Linux & Unix Commands - Search Man Pages

Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


MINCORE(2)			    Linux Programmer's Manual			       MINCORE(2)

NAME
       mincore - determine whether pages are resident in memory

SYNOPSIS
       #include <unistd.h>
       #include <sys/mman.h>

       int mincore(void *addr, size_t length, unsigned char *vec);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       mincore(): _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       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
       address addr, and continuing for length bytes.

       The addr argument must be a multiple of the system page size.  The  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) using sysconf(_SC_PAGESIZE).

       The  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 vec 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.

RETURN VALUE
       On  success, mincore() returns zero.  On error, -1 is returned, and errno is set appropri-
       ately.

ERRORS
       EAGAIN kernel is temporarily out of resources.

       EFAULT vec points to an invalid address.

       EINVAL addr is not a multiple of the page size.

       ENOMEM length is 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 EINVAL was returned for this con-
	      dition.

       ENOMEM addr to addr + length contained unmapped memory.

VERSIONS
       Available since Linux 2.3.99pre1 and glibc 2.2.

CONFORMING TO
       mincore()  is not specified in POSIX.1-2001, and it is not available on all UNIX implemen-
       tations.

BUGS
       Before kernel 2.6.21, mincore() did not return correct information  for	MAP_PRIVATE  map-
       pings, or for nonlinear mappings (established using remap_file_pages(2)).

SEE ALSO
       mlock(2), mmap(2)

COLOPHON
       This  page  is  part of release 3.53 of the Linux man-pages project.  A description of the
       project,    and	  information	 about	  reporting    bugs,	can    be    found     at
       http://www.kernel.org/doc/man-pages/.

Linux					    2008-04-22				       MINCORE(2)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 05:01 AM.

Unix & Linux Forums Content Copyright©1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password





Not a Forum Member?
Forgot Password?