fundal_dev_handling

FUNDAL, device handling module.

Source: src/lib/fundal_dev_handling.F90

Dependencies

Contents

• host_fallback_policy
• dev_get_device_memory_info
• dev_get_property_string
• dev_set_device_num
• dev_init
• dev_is_host_fallback
• env_upper
• dev_get_device_num
• dev_get_device_type
• dev_get_host_num
• dev_get_num_devices

Variables

Name	Type	Attributes	Description
fallback_warned	logical		Host fallback warning already issued (once per process).

Subroutines

host_fallback_policy

Apply the host-fallback policy once dev_host_fallback is known: if a device is required (argument or environment) fail, returning FUNDAL_ERR_NO_DEVICE if ierr is present or stopping otherwise; else warn (once per process) that the run is on the host, unless the host was explicitly requested through the environment.

subroutine host_fallback_policy(require_device, forced_by, host_requested, ierr)

Arguments

Name	Type	Intent	Attributes	Description
require_device	logical	in		Device required by the caller.
forced_by	character(len=*)	in		Environment setting requiring a device, empty if none.
host_requested	logical	in		Host explicitly requested by the environment.
ierr	integer(kind=I4P)	out	optional	Error status.

dev_get_device_memory_info

Get the current device memory status.

subroutine dev_get_device_memory_info(mem_free, mem_total)

Arguments

Name	Type	Intent	Attributes	Description
mem_free	integer(kind=I8P)	out	optional	Free memory.
mem_total	integer(kind=I8P)	out	optional	Total memory.

Call graph

dev_get_property_string

Return the value of a device-property for the specified device. Note: host fallback does not provide such a runtime routine, added only for seamless unified API.

subroutine dev_get_property_string(dev_num, string, prefix, memory)

Arguments

Name	Type	Intent	Attributes	Description
dev_num	integer	in	value	Device ID.
string	character(len=*)	out		Stringified device property.
prefix	character(len=*)	in	optional	String prefix.
memory	integer(kind=I8P)	out	optional	Device memory.

dev_set_device_num

Set the runtime for the specified device type and device number, and make it the default device of FUNDAL (mydev). Note: host fallback does not provide such a runtime routine, added only for seamless unified API: mydev stays 0.

subroutine dev_set_device_num(dev_num)

Arguments

Name	Type	Intent	Attributes	Description
dev_num	integer	in	value	Device ID.

Call graph

dev_init

Initialize device. Note: the compile-time CPU mode (no device backend) is an explicit build choice, not a host fallback: nothing to initialize, dev_is_host_fallback stays false and require_device is ignored. Same signature as the device backends.

subroutine dev_init(local_rank, require_device, ierr)

Arguments

Name	Type	Intent	Attributes	Description
local_rank	integer(kind=I4P)	in	optional	Local rank in multi-processes split ID (unused).
require_device	logical	in	optional	Forbid the host fallback (unused).
ierr	integer(kind=I4P)	out	optional	Error status, always 0.

Call graph

Functions

dev_is_host_fallback

Return true if the library is compiled for a device backend (OpenACC/OpenMP) but dev_init found no device, so that "device" memory and kernels live on the host. Always false in the compile-time CPU mode (no backend) and before dev_init.

Returns: logical

function dev_is_host_fallback() result(is_fallback)

env_upper

Return the value of an environment variable, upper case and trimmed; empty if not set.

Returns: character(len=:)

function env_upper(name) result(val)

Arguments

Name	Type	Intent	Attributes	Description
name	character(len=*)	in		Variable name.

dev_get_device_num

Return the value of current device ID for the current thread. Note: host fallback does not provide such a runtime routine, added only for seamless unified API.

Returns: integer(kind=I4P)

function dev_get_device_num() result(device_num)

Call graph

dev_get_device_type

Return the device type. Note: host fallback does not provide such a runtime routine, added only for seamless unified API.

Returns: integer(kind=I4P)

function dev_get_device_type() result(devtype_)

dev_get_host_num

Return the value of current host ID for the current thread. Note: host fallback does not provide such a runtime routine, added only for seamless unified API.

Returns: integer(kind=I4P)

function dev_get_host_num() result(host_num)

dev_get_num_devices

Return the number of available (non host) devices. Note: host fallback does not provide such a runtime routine, added only for seamless unified API.

Returns: integer(kind=I4P)

function dev_get_num_devices() result(devices_number)