---
name: "mincore"
section: "2"
platform: "macos"
package: "xnu"
version: "12377.121.6"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/mincore"
---

# mincore(2)

determine residency of memory pages

## NAME

**mincore** – determine residency of memory pages

## SYNOPSIS

**#include \<sys/types.h\>**

**#include \<sys/mman.h\>**

*int*\

**mincore**(*caddr\_t addr*, *size\_t len*, *char \*vec*);

## DESCRIPTION

The **mincore**() system call allows a process to obtain information about whether pages are core resident. The current core residency of the pages is returned in the character array  *vec*. For each entry in the character array *vec*, the following bit values may be set depending upon the state of the page:

```
MINCORE_INCORE           0x1     /* Page is incore */
MINCORE_REFERENCED       0x2     /* Page has been referenced by us */
MINCORE_MODIFIED         0x4     /* Page has been modified by us */
MINCORE_REFERENCED_OTHER 0x8     /* Page has been referenced */
MINCORE_MODIFIED_OTHER  0x10     /* Page has been modified */
```

## RETURN VALUES

Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and *errno* is set to indicate the error.

## ERRORS

- \[EINVAL\]

  *addr* is not a valid address for user mode.

- \[EFAULT\]

  an error occurred trying to copy to the output character array *vec*.

## SEE ALSO

[madvise(2)](/madvise/2.md), [minherit(2)](/minherit/2.md), [mlock(2)](/mlock/2.md), [mprotect(2)](/mprotect/2.md), [msync(2)](/msync/2.md), [munmap(2)](/munmap/2.md)

## HISTORY

The **mincore**() function first appeared in 4.4BSD.