11686d59fe
As the cpu-partitioning profile does not use isolcpus=,
the kernel can end up creating long living timers on
nohz_full CPUs during early boot. Those timers will
fire later, causing jitter.
However, recent Linux kernel will always try to migrate
unpinned timers away from nohz_full CPUs when timer
migration is enabled which is what we want.
NOTE: Older kernels would migrate unpinned timers from
idle CPUs to busy CPUs without regard if the
CPU is nohz_full. This would certainly cause
trouble to applications that takes 100% of the
CPU in user-space (eg. DPDK). So, enabling
timer migration is only safe on recent kernels.
Resolves: rhbz#1408308
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
40 lines
1.4 KiB
Text
40 lines
1.4 KiB
Text
# tuned configuration
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#
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[main]
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summary=Optimize for CPU partitioning
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include=network-latency
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[variables]
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# User is responsible for updating variables.conf with variable content such as isolated_cores=X-Y
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include=/etc/tuned/cpu-partitioning-variables.conf
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# Non-isolated cores cpumask including offline cores
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isolated_cores_expanded=${f:cpulist_unpack:${isolated_cores}}
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isolated_cpumask=${f:cpulist2hex:${isolated_cores_expanded}}
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not_isolated_cores_expanded=${f:cpulist_invert:${isolated_cores_expanded}}
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isolated_cores_present_expanded=${f:cpulist_present:${isolated_cores}}
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not_isolated_cores_present_expanded=${f:cpulist_present:${not_isolated_cores_expanded}}
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not_isolated_cpumask=${f:cpulist2hex:${not_isolated_cores_expanded}}
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# Fail if isolated_cores contains CPUs which are not present
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assert=${f:assertion:isolated_cores contains present CPU(s):${isolated_cores_expanded}:${isolated_cores_present_expanded}}
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[sysctl]
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kernel.hung_task_timeout_secs = 600
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kernel.nmi_watchdog = 0
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vm.stat_interval = 10
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kernel.timer_migration = 1
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[sysfs]
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/sys/bus/workqueue/devices/writeback/cpumask = ${not_isolated_cpumask}
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/sys/devices/virtual/workqueue/cpumask = ${not_isolated_cpumask}
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/sys/devices/system/machinecheck/machinecheck*/ignore_ce = 1
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[script]
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script=script.sh
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[systemd]
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cpu_affinity=${not_isolated_cores_expanded}
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[bootloader]
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cmdline= nohz=on nohz_full=${isolated_cores} rcu_nocbs=${isolated_cores} intel_pstate=disable nosoftlockup
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