---
name: "FUTEX_REQUEUE"
section: "2const"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/FUTEX_REQUEUE"
---

# FUTEX\_REQUEUE(2const)

wake some waiters, and requeue others

## NAME

FUTEX\_REQUEUE - wake some waiters, and requeue others

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <linux/futex.h>  /* Definition of FUTEX_* constants */
#include <sys/syscall.h>  /* Definition of SYS_* constants */
#include <unistd.h>
```

**long syscall(SYS\_futex, uint32\_t \****uaddr***, FUTEX\_REQUEUE,**              **uint32\_t** *val***, uint32\_t** *val2***, uint32\_t \****uaddr2***);**

## DESCRIPTION

This operation performs the same task as [**FUTEX\_CMP\_REQUEUE**(2const)](/FUTEX_CMP_REQUEUE/2const.md), except that the futex word isn't compared.

## RETURN VALUE

On error, -1 is returned, and *errno* is set to indicate the error.

On success, **FUTEX\_REQUEUE** returns the number of waiters that were woken up.

## ERRORS

See [**futex**(2)](/futex/2.md).

- **EFAULT**

  *uaddr2* did not point to a valid user-space address.

- **EINVAL**

  *uaddr2* does not point to a valid object—that is, the address is not four-byte-aligned.

- **EINVAL**

  The kernel detected an inconsistency between the user-space state at *uaddr* and the kernel state—that is, it detected a waiter which waits in [**FUTEX\_LOCK\_PI**(2const)](/FUTEX_LOCK_PI/2const.md) or [**FUTEX\_LOCK\_PI2**(2const)](/FUTEX_LOCK_PI2/2const.md) on *uaddr*.

## STANDARDS

Linux.

## HISTORY

Linux 2.6.0.

## SEE ALSO

[**futex**(2)](/futex/2.md)