genode/repos/base-hw/run/cpu_quota.run
Martin Stein 8f9355b360 thread API & CPU session: accounting of CPU quota
In the init configuration one can configure the donation of CPU time via
'resource' tags that have the attribute 'name' set to "CPU" and the
attribute 'quantum' set to the percentage of CPU quota that init shall
donate. The pattern is the same as when donating RAM quota.

! <start name="test">
!   <resource name="CPU" quantum="75"/>
! </start>

This would cause init to try donating 75% of its CPU quota to the child
"test".  Init and core do not preserve CPU quota for their own
requirements by default as it is done with RAM quota.

The CPU quota that a process owns can be applied through the thread
constructor. The constructor has been enhanced by an argument that
indicates the percentage of the programs CPU quota that shall be granted
to the new thread. So 'Thread(33, "test")' would cause the backing CPU
session to try to grant 33% of the programs CPU quota to the thread
"test". By now, the CPU quota of a thread can't be altered after
construction. Constructing a thread with CPU quota 0 doesn't mean the
thread gets never scheduled but that the thread has no guaranty to receive
CPU time. Such threads have to live with excess CPU time.

Threads that already existed in the official repositories of Genode were
adapted in the way that they receive a quota of 0.

This commit also provides a run test 'cpu_quota' in base-hw (the only
kernel that applies the CPU-quota scheme currently). The test basically
runs three threads with different physical CPU quota. The threads simply
count for 30 seconds each and the test then checks wether the counter
values relate to the CPU-quota distribution.

fix #1275
2014-11-28 12:02:37 +01:00

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#
# 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="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="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="CAP"/>
<service name="PD"/>
<service name="RM"/>
<service name="CPU"/>
<service name="LOG"/>
<service name="SIGNAL"/>
<service name="Timer"/>
</parent-provides>
<default-route>
<any-service><parent/><any-child/></any-service>
</default-route>
<!-- should receive 10 % of the CPU time -->
<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="CPU"/>
<service name="RM"/>
<service name="CAP"/>
<service name="PD"/>
<service name="LOG"/>
<service name="SIGNAL"/>
<service name="Timer"/>
</parent-provides>
<default-route>
<any-service><parent/></any-service>
</default-route>
<!-- should receive 25 % of the CPU time -->
<start name="test_middle">
<binary name="test-cpu_quota"/>
<resource name="RAM" quantum="10M"/>
<resource name="CPU" quantum="25"/>
</start>
<!-- should receive 65 % of the CPU time -->
<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"
#
# Execution
#
append qemu_args "-nographic -m 64"
run_genode_until "test.*\n.*test.*\n.*test.*\n" 60
#
# Conclusion
#
set slow_opt 0.10
set middle_opt 0.25
set fast_opt 0.65
set err 0.02
regexp {[0-9]+} [regexp -inline {slow.*[0-9]+} $output] slow_cnt
regexp {[0-9]+} [regexp -inline {middle.*[0-9]+} $output] middle_cnt
regexp {[0-9]+} [regexp -inline {fast.*[0-9]+} $output] fast_cnt
set total_cnt [expr $fast_cnt + $middle_cnt + $slow_cnt]
set slow_fac [expr $slow_cnt / double($total_cnt) ]
set middle_fac [expr $middle_cnt / double($total_cnt) ]
set fast_fac [expr $fast_cnt / double($total_cnt) ]
set failed 0
if {[expr $slow_fac > $slow_opt + $err || $slow_fac < $slow_opt - $err]} {
set is_pc [expr round($slow_fac * 10000) / 100]
set opt_pc [expr round($slow_opt * 10000) / 100]
puts stderr "Error: Slow counter received $is_pc% of the CPU time."
puts stderr " Should receive $opt_pc%."
set failed 1
}
if {[expr $middle_fac > $middle_opt + $err || $middle_fac < $middle_opt - $err]} {
set is_pc [expr round($middle_fac * 10000) / 100]
set opt_pc [expr round($middle_opt * 10000) / 100]
puts stderr "Error: Middle counter received $is_pc% of the CPU time."
puts stderr " Should receive $opt_pc%."
set failed 1
}
if {[expr $fast_fac > $fast_opt + $err || $fast_fac < $fast_opt - $err]} {
set is_pc [expr round($fast_fac * 10000) / 100]
set opt_pc [expr round($fast_opt * 10000) / 100]
puts stderr "Error: Fast counter received $is_pc% of the CPU time."
puts stderr " Should receive $opt_pc%."
set failed 1
}
if {$failed} {
exit -1
} else {
puts "Test succeeded"
}