genode/repos/os/run/cpu_quota.run

#
# Check platform
#
# HW is the only kernel that provides appliance of quota to the scheduling.
# On X86, the timer driver uses the PIT with a timeout of max. 54 ms. Thus,
# the driver needs to restart the timer permanently which is a hard job with 6
# high-priority counter-threads in the background. As a consequence, timeouts
# take much longer than requested and the test fails.  However, as the PIT
# tends to be replaced by a better timing source, we simply skip X86 for now.
#
#
assert_spec hw
assert_spec arm

#
# Build
#

build "core init drivers/timer test/cpu_quota"

#
# Boot image
#

create_boot_directory

install_config {
<config prio_levels="4">
	<parent-provides>
		<service name="ROM"/>
		<service name="RAM"/>
		<service name="IRQ"/>
		<service name="IO_MEM"/>
		<service name="IO_PORT"/>
		<service name="CAP"/>
		<service name="PD"/>
		<service name="RM"/>
		<service name="CPU"/>
		<service name="LOG"/>
		<service name="SIGNAL"/>
	</parent-provides>
	<default-route>
		<any-service><parent/><any-child/></any-service>
	</default-route>

	<start name="timer">
		<resource name="RAM" quantum="10M"/>
		<provides><service name="Timer"/></provides>
	</start>

	<start name="test-sync">
		<resource name="RAM" quantum="10M"/>
		<provides><service name="Sync"/></provides>
	</start>

	<start name="init_1" priority="-1">
		<binary name="init"/>
		<resource name="RAM" quantum="10M"/>
		<resource name="CPU" quantum="10"/>
		<config prio_levels="2">
			<parent-provides>
				<service name="ROM"/>
				<service name="RAM"/>
				<service name="IRQ"/>
				<service name="IO_MEM"/>
				<service name="IO_PORT"/>
				<service name="CAP"/>
				<service name="PD"/>
				<service name="RM"/>
				<service name="CPU"/>
				<service name="LOG"/>
				<service name="SIGNAL"/>
				<service name="Timer"/>
				<service name="Sync"/>
			</parent-provides>
			<default-route>
				<any-service><parent/><any-child/></any-service>
			</default-route>

			<start name="test_slow" priority="-1">
				<binary name="test-cpu_quota"/>
				<resource name="RAM" quantum="10M"/>
				<resource name="CPU" quantum="50"/>
			</start>

		</config>
	</start>

	<start name="init_2" priority="-2">
		<binary name="init"/>
		<resource name="RAM" quantum="100M"/>
		<resource name="CPU" quantum="80"/>
		<config>
			<parent-provides>
				<service name="ROM"/>
				<service name="RAM"/>
				<service name="IRQ"/>
				<service name="IO_MEM"/>
				<service name="IO_PORT"/>
				<service name="CAP"/>
				<service name="PD"/>
				<service name="RM"/>
				<service name="CPU"/>
				<service name="LOG"/>
				<service name="SIGNAL"/>
				<service name="Timer"/>
				<service name="Sync"/>
			</parent-provides>
			<default-route>
				<any-service><parent/></any-service>
			</default-route>

			<start name="test_midl">
				<binary name="test-cpu_quota"/>
				<resource name="RAM" quantum="10M"/>
				<resource name="CPU" quantum="25"/>
			</start>

			<start name="test_fast">
				<binary name="test-cpu_quota"/>
				<resource name="RAM" quantum="10M"/>
				<resource name="CPU" quantum="75"/>
			</start>

		</config>
	</start>
</config>
}

build_boot_image "core init timer test-cpu_quota test-sync"

#
# Execution
#

append qemu_args "-nographic -m 64"

run_genode_until ".*done.*\n.*done.*\n.*done.*\n" 100

#
# Conclusion
#

proc check_counter { name opt cnt total_cnt } {

	set err         1
	set is          [expr double($cnt) / $total_cnt ]
	set is_pc       [expr double(round($is  * 100000)) / 1000]
	set opt_pc      [expr double(round($opt * 100000)) / 1000]

	if {[expr $is > $opt + $err || $is < $opt - $err]} {
		puts stderr "Error: $name received $is_pc % of the CPU time."
		puts stderr "       Should receive $opt_pc %."
		exit -1
	}
	puts "$name: $is_pc % (optimal $opt_pc %)"
}

proc check_quota { name opt_sp quota_sp opt quota } {

	if {[expr $quota != $opt]} {
		puts stderr "Error: $name has CPU quota of $quota us."
		puts stderr "       Should have $opt us."
		exit -1
	}
	if {[expr $quota_sp != $opt_sp]} {
		puts stderr "Error: $name has CPU quota super-period of $quota_sp us."
		puts stderr "       Should have $opt_sp us."
		exit -1
	}
}

regexp {[0-9]+} [regexp -inline {slow. quota [0-9]+} $output] slow_quota
regexp {[0-9]+} [regexp -inline {midl. quota [0-9]+} $output] midl_quota
regexp {[0-9]+} [regexp -inline {fast. quota [0-9]+} $output] fast_quota

regexp {[0-9]+} [regexp -inline {slow. quota super period [0-9]+} $output] slow_quota_sp
regexp {[0-9]+} [regexp -inline {midl. quota super period [0-9]+} $output] midl_quota_sp
regexp {[0-9]+} [regexp -inline {fast. quota super period [0-9]+} $output] fast_quota_sp

#
# We have to consider the rounding errors as the two translations from init to
# core and then from core to the user are distinct.
#
# Slow quota (1000000 * (0x8000 *  5 / 100)) / 0x8000 =  49987
# Slow quota (1000000 * (0x8000 * 20 / 100)) / 0x8000 = 199981
# Slow quota (1000000 * (0x8000 * 60 / 100)) / 0x8000 = 599975
#
check_quota "Slow test"   1000000 $slow_quota_sp  49987 $slow_quota
check_quota "Middle test" 1000000 $midl_quota_sp 199981 $midl_quota
check_quota "Fast test"   1000000 $fast_quota_sp 599975 $fast_quota

regexp {[0-9]+} [regexp -inline {slow. counter A [0-9]+} $output] slow_a_cnt
regexp {[0-9]+} [regexp -inline {midl. counter A [0-9]+} $output] midl_a_cnt
regexp {[0-9]+} [regexp -inline {fast. counter A [0-9]+} $output] fast_a_cnt
regexp {[0-9]+} [regexp -inline {slow. counter B [0-9]+} $output] slow_b_cnt
regexp {[0-9]+} [regexp -inline {midl. counter B [0-9]+} $output] midl_b_cnt
regexp {[0-9]+} [regexp -inline {fast. counter B [0-9]+} $output] fast_b_cnt

set total_cnt [expr $fast_a_cnt + $midl_a_cnt + $slow_a_cnt + $fast_b_cnt + $midl_b_cnt + $slow_b_cnt]

#
# Slow   5.0 % claim + 5.0 % fill = 10 %
#   Stage 1
#     A  0.5 % claim + 2.5 % fill =  3 %
#     B  4.5 % claim + 2.5 % fill =  7 %
#   Stage 2
#     A  5.0 % claim + 5.0 % fill = 10 %
#   Total
#     A  3/4 * 3 + 1/4 * 10 = 4.75 %
#     A  3/4 * 7 + 1/4 *  0 = 5.25 %
#
check_counter "Slow counter A"   0.0475 $slow_a_cnt $total_cnt
check_counter "Slow counter B"   0.0525 $slow_b_cnt $total_cnt

#
# Middle 20 % claim + 5.0 % fill = 25.0 %
#   Stage 1
#     A   2 % claim + 2.5 % fill =  4.5 %
#     B  18 % claim + 2.5 % fill = 20.5 %
#   Stage 2
#     A  20 % claim + 5.0 % fill = 25.0 %
#   Total
#     A  3/4 *  4.5 + 1/4 * 25 =  9.625 %
#     A  3/4 * 20.5 + 1/4 *  0 = 15.375 %
#
check_counter "Middle counter A" 0.09625 $midl_a_cnt $total_cnt
check_counter "Middle counter B" 0.15375 $midl_b_cnt $total_cnt

#
# Fast   60 % claim + 5.0 % fill = 65.0 %
#   Stage 1
#     A   6 % claim + 2.5 % fill =  8.5 %
#     B  54 % claim + 2.5 % fill = 56.5 %
#   Stage 2
#     A  60 % claim + 5.0 % fill = 65.0 %
#   Total
#     A  3/4 *  8.5 + 1/4 * 65 = 22.625 %
#     A  3/4 * 56.5 + 1/4 *  0 = 42.375 %
#
check_counter "Fast counter A" 0.22625 $fast_a_cnt $total_cnt
check_counter "Fast counter B" 0.42375 $fast_b_cnt $total_cnt

puts "Test succeeded"