pr_sve_get_vl(2const)

NAME#

PR_SVE_GET_VL - get the thread's SVE vector length

LIBRARY#

Standard C library (libc, -lc)

SYNOPSIS#

#include <linux/prctl.h>\n  /* Definition of \nPR_*\n constants */
\n#include <sys/prctl.h>

int prctl(PR_SVE_GET_VL);

DESCRIPTION#

Get the thread's current SVE vector length configuration.

This operation returns a nonnegative value that describes the current configuration. The bits corresponding to PR_SVE_VL_LEN_MASK contain the currently configured vector length in bytes. The bit corresponding to PR_SVE_VL_INHERIT indicates whether the vector length will be inherited across execve(2).

RETURN VALUE#

On success, PR_SVE_GET_VL, return the nonnegative values described above. On error, -1 is returned, and errno is set to indicate the error.

ERRORS#

EINVAL

SVE is not available on this platform.

STANDARDS#

Linux. arm64 only.

HISTORY#

Linux 4.15 (arm64).

CAVEATS#

There is no way to determine whether there is a pending vector length change that has not yet taken effect.

SEE ALSO#

prctl(2), PR_SVE_SET_VL(2const)

For more information, see the kernel source file Documentation/arm64/sve.rst (or Documentation/arm64/sve.txt before Linux 5.3).