ovni/test/rt/nosv/nosv.toml

# This file is part of nOS-V and is licensed under the terms contained in the COPYING file
#
# Copyright (C) 2021-2022 Barcelona Supercomputing Center (BSC)

# Default nOS-V configuration file.
# Note that every process in the same nOS-V instance should load an identical configuration file,
# otherwise, the behaviour is unspecified

# Shared memory configuration
[shared_memory]
	# Name of the shared memory section. This can be leveraged to create two separate nOS-V instances
	# in the same system. Generally this has to remain unchanged
	name = "nosv"
	# Size of the shared memory section. Choose powers of two
	size = "2G"
	# Start of the shared memory mapping
	# This option should be memory address codified in hexadecimal (start with 0x)
	start = 0x0000200000000000

# Scheduler configuration
# These parameters allow to fine tune the scheduler's behaviour
[scheduler]
	# Number of logical CPUs mapped to a single scheduler SPSC for ready tasks
	# Minimum is 1, there is no maximum. Try to choose numbers that divide evenly the number
	# of CPUs in the system.
	# A lower number will yield more scheduling throughput and is adequate when using
	# multiple task creator processes.
	# A higher number will yield lower scheduling latency and is adequate when using one or few
	# task creator processes
	cpus_per_queue = 1
	# Number of tasks that are grabbed off of a queue when processing ready tasks.
	# Lowering the number may be better if there are very few ready tasks during execution.
	# Increasing the batch may help if your CPU has bad single-thread performance.
	# In general, the default value of 64 should result in a good trade-off
	queue_batch = 64
	# Scheduler quantum in ns. This is a guideline for how long should we execute one process' tasks
	# until we have to switch to the next one. However, as nOS-V tasks are not preemptable, it isn't enforced.
	# This parameter is specially relevant for the nosv_schedpoint function, which will try to schedule
	# each quantum ns.
	# A lower value will cause more inter-process context switches but may provide more uniform progress,
	# while a higher value will minimize context switches but may stall applications for longer
	quantum_ns = 20000000 # nanoseconds
	# Size of the queues that are used to place tasks into the scheduler
	# A good value should be a multiple of queue_batch
	in_queue_size = 256

# CPU Governor configuration
# Controls the policy that nOS-V follows to block idle CPUs to save energy and resources
[governor]
	# There is a choice between three different governor policies:
	# - hybrid: CPUs will spin for governor.spins before going to sleep when no work is available
	# - idle: CPUs will sleep immediately when no work is available
	# - busy: CPUs will never sleep
	# In general, use idle when targeting minimum power usage, and busy when targeting maximum performance
	# The default is hybrid as it provides a good balance between power and performance.
	policy = "hybrid"
	# Number of times a CPU will spin without sleeping in the "hybrid" policy.
	# When "idle" or "busy" are selected, this setting is ignored
	spins = 10000

# Debug options
[debug]
	# Dump all the configuration options nOS-V is running with, its final parsed values and the
	# path of the config file being used
	dump_config = false

# Hardware Counters configuration
[hwcounters]
	# Whether to print verbose information if a backend is enabled
	verbose = false
	# The enabled HWCounter backends. Possible options: "papi", "none"
	backend = "none"
	# The list of PAPI counters to read. By default only "PAPI_TOT_INS" and "PAPI_TOT_CYC"
	papi_events = [
		"PAPI_TOT_INS",
		"PAPI_TOT_CYC"
	]

# Enabling turbo will cause nOS-V to set architecture-specific optimization flags on every created
# or attached threads. In x86, this will cause the FTZ and DAZ flags of the SSE FPU to be enabled,
# causing a significant performance increase in floating-point applications, but disabling IEEE-754
# compatibility.
[turbo]
	enabled = false

# Monitoring cappabilities and configuration.
[monitoring]
	enabled = false
	# Whether to print verbose information if monitoring is enabled
	verbose = false