---
name: "sched_getcpu"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/sched_getcpu"
---

# sched\_getcpu(3)

determine CPU on which the calling thread is running

## NAME

sched\_getcpu - determine CPU on which the calling thread is running

## LIBRARY

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

## SYNOPSIS

```
#include <sched.h>
```

**int sched\_getcpu(void);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**sched\_getcpu**():

```
    Since glibc 2.14:
        _GNU_SOURCE
    Before glibc 2.14:
        _BSD_SOURCE || _SVID_SOURCE
            /* _GNU_SOURCE also suffices */
```

## DESCRIPTION

**sched\_getcpu**() returns the number of the CPU on which the calling thread is currently executing.

## RETURN VALUE

On success, **sched\_getcpu**() returns a nonnegative CPU number. On error, -1 is returned and *errno* is set to indicate the error.

## ERRORS

- **ENOSYS**

  This kernel does not implement [**getcpu**(2)](/getcpu/2.md).

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **sched\_getcpu**() | Thread safety | MT-Safe |

## STANDARDS

GNU.

## HISTORY

glibc 2.6.

## NOTES

The call

```
cpu = sched_getcpu();
```

is equivalent to the following [**getcpu**(2)](/getcpu/2.md) call:

```
int c, s;
s = getcpu(&c, NULL);
cpu = (s == -1) ? s : c;
```

## SEE ALSO

[**getcpu**(2)](/getcpu/2.md), [**sched**(7)](/sched/7.md)