Messages in this thread | | | From | Wanpeng Li <> | Subject | [PATCH 0/3] KVM: Dynamic halt_poll_ns | Date | Mon, 24 Aug 2015 20:53:21 +0800 |
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There is a downside of halt_poll_ns since poll is still happen for idle VCPU which can waste cpu usage. This patchset add the ability to adjust halt_poll_ns dynamically, grows halt_poll_ns if an interrupt arrives and shrinks halt_poll_ns when idle VCPU is detected.
There are two new kernel parameters for changing the halt_poll_ns: halt_poll_ns_grow and halt_poll_ns_shrink. halt_poll_ns_grow affects halt_poll_ns when an interrupt arrives and halt_poll_ns_shrink does it when idle VCPU is detected.
halt_poll_ns_shrink/ | halt_poll_ns_grow | interrupt arrives | idle VCPU is detected ---------------------+----------------------+------------------- < 1 | = halt_poll_ns | = 0 < halt_poll_ns | *= halt_poll_ns_grow | /= halt_poll_ns_shrink otherwise | += halt_poll_ns_grow | -= halt_poll_ns_shrink
A third new parameter, halt_poll_ns_max, controls the maximal halt_poll_ns; it is internally rounded down to a closest multiple of halt_poll_ns_grow.
Wanpeng Li (3): KVM: make halt_poll_ns per-VCPU KVM: dynamise halt_poll_ns adjustment KVM: trace kvm_halt_poll_ns grow/shrink
include/linux/kvm_host.h | 1 + include/trace/events/kvm.h | 30 ++++++++++++++++ virt/kvm/kvm_main.c | 90 +++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 120 insertions(+), 1 deletion(-)
-- 1.9.1
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