bus_get_cpus (9)

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Copyright (c) 2016 John H. Baldwin <jhb@FreeBSD.org>
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(The comments found at the beginning of the groff file "man9/bus_get_cpus.9freebsd".)

NAME

BUS_GET_CPUS bus_get_cpus - request a set of device-specific CPUs

SYNOPSIS

In sys/param.h In sys/bus.h In sys/cpuset.h Ft int Fo BUS_GET_CPUS Fa device_t dev device_t child enum cpu_sets op size_t setsize Fa cpuset_t *cpuset Fc Ft int Fo bus_get_cpus Fa device_t dev enum cpu_sets op size_t setsize cpuset_t *cpuset Fc

DESCRIPTION

The Fn BUS_GET_CPUS method queries the parent bus device for a set of device-specific CPUs. The Fa op argument specifies which set of CPUs to retrieve. If successful, the requested set of CPUs are returned in Fa cpuset . The Fa setsize argument specifies the size in bytes of the set passed in Fa cpuset .

Fn BUS_GET_CPUS supports querying different types of CPU sets via the Fa op argument. Not all set types are supported for every device. If a set type is not supported, Fn BUS_GET_CPUS fails with Er EINVAL . These set types are supported:

LOCAL_CPUS

The set of CPUs that are local to the device. If a device is closer to a specific memory domain in a non-uniform memory architecture system (NUMA) this will return the set of CPUs in that memory domain.

INTR_CPUS

The preferred set of CPUs that this device should use for device interrupts. This set type must be supported by all bus drivers.

The Fn bus_get_cpus function is a simple wrapper around Fn BUS_GET_CPUS .

RETURN VALUES

Zero is returned on success, otherwise an appropriate error is returned.

SEE ALSO

cpuset(2), BUS_BIND_INTR9, device(9)

HISTORY

The Fn BUS_GET_CPUS method and Fn bus_get_cpus function first appeared in Fx 11.0 .