virt/kvm/halt-polling.rst

1 .. SPDX-License-Identifier: GPL-2.0
16 the order of a few micro-seconds, although performance benefits are workload
27 The powerpc kvm-hv specific case is implemented in:
39 	kvm_vcpu->halt_poll_ns
41 or in the case of powerpc kvm-hv, in the vcore struct:
43 	kvmppc_vcore->halt_poll_ns
50 two options, either the polling interval and total block time[0] were less than
54 In the event that both the polling interval and total block time were less than
66 shrink_halt_poll_ns() and is divided by the module parameter
86 arch/powerpc/kvm/book3s_hv.c in the powerpc kvm-hv case.
88 +-----------------------+---------------------------+-------------------------+
89 |Module Parameter	|   Description		    |	     Default Value    |
90 +-----------------------+---------------------------+-------------------------+
96 +-----------------------+---------------------------+-------------------------+
102 +-----------------------+---------------------------+-------------------------+
107 +-----------------------+---------------------------+-------------------------+
113 +-----------------------+---------------------------+-------------------------+
119 Note: these module parameters are system-wide values and are not able to
130 on a per-VM basis. VMs using KVM_CAP_HALT_POLL ignore halt_poll_ns completely (but
138 - Care should be taken when setting the halt_poll_ns module parameter as a large value
145 - Halt polling essentially presents a trade-off between power usage and latency and
150 - Halt polling will only be conducted by the host when no other tasks are runnable on