---
name: "io_uring_cq_eventfd_toggle"
section: "3"
platform: "linux"
package: "liburing"
version: "2.15-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/io_uring_cq_eventfd_toggle"
---

# io\_uring\_cq\_eventfd\_toggle(3)

toggle eventfd notifications on or off

## NAME

io\_uring\_cq\_eventfd\_toggle - toggle eventfd notifications on or off

## SYNOPSIS

```
#include <liburing.h>
```

**int io\_uring\_cq\_eventfd\_toggle(struct io\_uring \****ring***, bool** *enabled***);**

## DESCRIPTION

The [**io\_uring\_cq\_eventfd\_toggle**(3)](/io_uring_cq_eventfd_toggle/3.md) function toggles eventfd notifications for the io\_uring instance specified by *ring*. If *enabled* is **true**, eventfd notifications are enabled. If *enabled* is **false**, they are disabled.

An eventfd must first be registered with the ring using [**io\_uring\_register\_eventfd**(3)](/io_uring_register_eventfd/3.md) or [**io\_uring\_register\_eventfd\_async**(3)](/io_uring_register_eventfd_async/3.md) before this function can be used.

This can be useful when the application wants to temporarily stop receiving eventfd notifications, for example during a batch processing phase.

## RETURN VALUE

Returns 0 on success. On error, a negative errno value is returned:

- **-EOPNOTSUPP**

  The kernel does not support toggling eventfd notifications, or no eventfd is registered.

## SEE ALSO

[**io\_uring\_register\_eventfd**(3)](/io_uring_register_eventfd/3.md), [**io\_uring\_register\_eventfd\_async**(3)](/io_uring_register_eventfd_async/3.md), [**io\_uring\_cq\_eventfd\_enabled**(3)](/io_uring_cq_eventfd_enabled/3.md)