Lines Matching +full:allow +full:- +full:set +full:- +full:time
1 # SPDX-License-Identifier: GPL-2.0-only
3 # RCU-related configuration options
11 # Dynticks-idle tracking
26 thousands of CPUs, but for which real-time response
37 designed for UP systems from which real-time response
42 bool "Make expert-level adjustments to RCU configuration"
46 expert-level adjustments to RCU configuration. By default,
47 no such adjustments can be made, which has the often-beneficial
48 side-effect of preventing "make oldconfig" from asking you all
50 obscure RCU options to be set up.
52 Say Y if you need to make expert-level adjustments to RCU.
60 This option selects the single-CPU non-preemptible version of SRCU.
66 This option selects the full-fledged version of SRCU.
75 task-based RCU implementations. Not for manual selection.
83 This option force-enables a task-based RCU implementation
85 idle, and user-mode execution as quiescent states. Not for
99 This option force-enables a task-based RCU implementation
101 user-mode execution as quiescent states. It forces IPIs and
116 This option enables a task-based RCU implementation that uses
117 explicit rcu_read_lock_trace() read-side markers, and allows
132 the TINY and TREE variants of RCU. The purpose is to allow
140 int "Tree-based hierarchical RCU fanout value"
152 systems, but if you are stress-testing the RCU implementation
153 itself, small RCU_FANOUT values allow you to test large-system
160 int "Tree-based hierarchical RCU leaf-level fanout value"
168 This option controls the leaf-level fanout of hierarchical
171 scheduling-clock interrupts for energy-efficiency reasons will
172 want the default because the smaller leaf-level fanout keeps
174 (hundreds or thousands of CPUs) will instead want to set this
176 number of cache misses incurred during RCU's grace-period
177 initialization. These systems tend to run CPU-bound, and thus
180 leaf-level fanouts work well. That said, setting leaf-level
182 lock contention on the leaf-level rcu_node structures unless
188 please understand that you may also need to set the skew_tick
204 Say Y here if you are working with real-time apps or heavy loads
208 int "Milliseconds to delay boosting after RCU grace-period start"
213 This option specifies the time to wait after the beginning of
214 a given grace period before priority-boosting preempted RCU
221 bool "Perform RCU expedited work in a real-time kthread"
235 bool "Offload RCU callback processing from boot-selected CPUs"
241 real-time workloads. It can also be used to offload RCU
242 callback invocation to energy-efficient CPUs in battery-powered
245 workloads will incur significant increases in context-switch
248 This option offloads callback invocation from the set of CPUs
249 specified at boot time by the rcu_nocbs parameter. For each
252 the "x" is "p" for RCU-preempt (PREEMPTION kernels) and "s" for
253 RCU-sched (!PREEMPTION kernels). Nothing prevents this kthread
256 be used to force the kthreads to run on whatever set of CPUs is
276 bool "Offload RCU callback from real-time kthread"
285 it is your responsibility to ensure that latency-sensitive
288 Say Y here if you want to set RT priority for offloading kthreads.
302 real-time installations and for battery-powered devices,
306 Say N here if you hate read-side memory barriers.
318 bool "RCU callback-batch backup time check"
325 thus defeating the 32-callback batching used to amortize the
326 cost of the fine-grained but expensive local_clock() function.
329 jiffy, and overrides the 32-callback batching if this limit
332 Say Y here if you need tighter callback-limit enforcement.