Lines Matching +full:allow +full:- +full:set +full:- +full:time
1 # SPDX-License-Identifier: GPL-2.0-only
3 # RCU-related configuration options
24 thousands of CPUs, but for which real-time response
35 designed for UP systems from which real-time response
40 bool "Make expert-level adjustments to RCU configuration"
44 expert-level adjustments to RCU configuration. By default,
45 no such adjustments can be made, which has the often-beneficial
46 side-effect of preventing "make oldconfig" from asking you all
48 obscure RCU options to be set up.
50 Say Y if you need to make expert-level adjustments to RCU.
58 permits arbitrary sleeping or blocking within RCU read-side critical
65 This option selects the single-CPU non-preemptible version of SRCU.
71 This option selects the full-fledged version of SRCU.
78 task-based RCU implementations. Not for manual selection.
83 This option enables a task-based RCU implementation that uses
85 user-mode execution as quiescent states. Not for manual selection.
90 This option enables a task-based RCU implementation that uses
91 only context switch (including preemption) and user-mode
100 This option enables a task-based RCU implementation that uses
101 explicit rcu_read_lock_trace() read-side markers, and allows
110 the TINY and TREE variants of RCU. The purpose is to allow
118 int "Tree-based hierarchical RCU fanout value"
130 systems, but if you are stress-testing the RCU implementation
131 itself, small RCU_FANOUT values allow you to test large-system
138 int "Tree-based hierarchical RCU leaf-level fanout value"
146 This option controls the leaf-level fanout of hierarchical
149 scheduling-clock interrupts for energy-efficiency reasons will
150 want the default because the smaller leaf-level fanout keeps
152 (hundreds or thousands of CPUs) will instead want to set this
154 number of cache misses incurred during RCU's grace-period
155 initialization. These systems tend to run CPU-bound, and thus
158 leaf-level fanouts work well. That said, setting leaf-level
160 lock contention on the leaf-level rcu_node structures unless
166 please understand that you may also need to set the skew_tick
173 bool "Accelerate last non-dyntick-idle CPU's grace periods"
177 This option permits CPUs to enter dynticks-idle state even if
186 don't care about increased grace-period durations.
200 Say Y here if you are working with real-time apps or heavy loads
204 int "Milliseconds to delay boosting after RCU grace-period start"
209 This option specifies the time to wait after the beginning of
210 a given grace period before priority-boosting preempted RCU
217 bool "Offload RCU callback processing from boot-selected CPUs"
223 real-time workloads. It can also be used to offload RCU
224 callback invocation to energy-efficient CPUs in battery-powered
227 workloads will incur significant increases in context-switch
230 This option offloads callback invocation from the set of CPUs
231 specified at boot time by the rcu_nocbs parameter. For each
234 the "x" is "p" for RCU-preempt (PREEMPTION kernels) and "s" for
235 RCU-sched (!PREEMPTION kernels). Nothing prevents this kthread
238 be used to force the kthreads to run on whatever set of CPUs is
255 real-time installations and for battery-powered devices,
259 Say N here if you hate read-side memory barriers.