Lines Matching +full:poll +full:- +full:interval

1 .. SPDX-License-Identifier: GPL-2.0
16 the order of a few micro-seconds, although performance benefits are workload
18 interval or some other task on the runqueue is runnable the scheduler is
27 The powerpc kvm-hv specific case is implemented in:
31 Halt Polling Interval
34 The maximum time for which to poll before invoking the scheduler, referred to
35 as the halt polling interval, is increased and decreased based on the perceived
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
47 During polling if a wakeup source is received within the halt polling interval,
48 the interval is left unchanged. In the event that a wakeup source isn't
49 received during the polling interval (and thus schedule is invoked) there are
50 two options, either the polling interval and total block time[0] were less than
51 the global max polling interval (see module params below), or the total block
52 time was greater than the global max polling interval.
54 In the event that both the polling interval and total block time were less than
55 the global max polling interval then the polling interval can be increased in
56 the hope that next time during the longer polling interval the wake up source
58 received. The polling interval is grown in the function grow_halt_poll_ns() and
63 interval then the host will never poll for long enough (limited by the global
64 max) to wakeup during the polling interval so it may as well be shrunk in order
65 to avoid pointless polling. The polling interval is shrunk in the function
70 steady state polling interval but will only really do a good job for wakeups
72 adjustment of the polling interval.
83 polling interval as well as the rate at which the polling interval is grown and
86 powerpc kvm-hv case.
88 +-----------------------+---------------------------+-------------------------+
90 +-----------------------+---------------------------+-------------------------+
92 |			| interval which defines    |			      |
94 |			| polling interval for      | (per arch value)	      |
96 +-----------------------+---------------------------+-------------------------+
98 |			| halt polling interval is  |			      |
102 +-----------------------+---------------------------+-------------------------+
107 +-----------------------+---------------------------+-------------------------+
109 |			| halt polling interval is  |			      |
113 +-----------------------+---------------------------+-------------------------+
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
142   global max polling interval (halt_poll_ns) then the host will always poll for the
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