io\_uring\_prep\_madvise(3) liburing Manual io\_uring\_prep\_madvise(3)

# [NAME](#NAME)

io\_uring\_prep\_madvise - prepare a madvise request

# [SYNOPSIS](#SYNOPSIS)

```
#include <sys/mman.h>
#include <liburing.h>
```

```
void io_uring_prep_madvise(struct io_uring_sqe *sqe,
                           void *addr,
                           __u32 len,
                           int advice);

void io_uring_prep_madvise64(struct io_uring_sqe *sqe,
                             void *addr,
                             off_t len,
                             int advice);
```

# [DESCRIPTION](#DESCRIPTION)

The [**io\_uring\_prep\_madvise**(3)](/man/os/liburing/io_uring_prep_madvise.3) function prepares an madvise request. The submission queue entry *sqe* is setup to start an madvise operation at the virtual address of *addr* and of *len* length in bytes, giving it the advise located in *advice*.

The [**io\_uring\_prep\_madvise64**(3)](/man/os/liburing/io_uring_prep_madvise64.3) function works like [**io\_uring\_prep\_madvise**(3)](/man/os/liburing/io_uring_prep_madvise.3) except that it takes a 64-bit length rather than just a 32-bit one. Older kernels may not support the 64-bit length variant. If this variant is attempted used on a kernel that doesn't support 64-bit lengths, then the request will get errored with **-EINVAL** in the results field of the CQE.

This function prepares an async [**madvise**(2)](/man/os/liburing/madvise.2) request. See that man page for details.

# [RETURN VALUE](#RETURN_VALUE)

None

# [ERRORS](#ERRORS)

The CQE *res* field will contain the result of the operation. See the related man page for details on possible values. Note that where synchronous system calls will return **-1** on failure and set *errno* to the actual error value, io\_uring never uses *errno*. Instead it returns the negated *errno* directly in the CQE *res* field.

# [SEE ALSO](#SEE_ALSO)

[**io\_uring\_get\_sqe**(3)](/man/os/liburing/io_uring_get_sqe.3), [**io\_uring\_submit**(3)](/man/os/liburing/io_uring_submit.3), [**io\_uring\_register**(2)](/man/os/liburing/io_uring_register.2), [**madvise**(2)](/man/os/liburing/madvise.2)

March 13, 2022 liburing-2.2

---

Document: io_uring_prep_madvise64(3) from liburing 2.15-r5 (Chainguard OS)
Source: https://github.com/axboe/liburing.git