Lines Matching +full:boot +full:- +full:up
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
103 This option force-enables a task-based RCU implementation
105 user-mode execution as quiescent states. It forces IPIs and
120 This option enables a task-based RCU implementation that uses
121 explicit rcu_read_lock_trace() read-side markers, and allows
144 int "Tree-based hierarchical RCU fanout value"
156 systems, but if you are stress-testing the RCU implementation
157 itself, small RCU_FANOUT values allow you to test large-system
164 int "Tree-based hierarchical RCU leaf-level fanout value"
172 This option controls the leaf-level fanout of hierarchical
175 scheduling-clock interrupts for energy-efficiency reasons will
176 want the default because the smaller leaf-level fanout keeps
180 number of cache misses incurred during RCU's grace-period
181 initialization. These systems tend to run CPU-bound, and thus
184 leaf-level fanouts work well. That said, setting leaf-level
186 lock contention on the leaf-level rcu_node structures unless
187 you boot with the skew_tick kernel parameter.
193 kernel boot parameter to avoid contention on the rcu_node
208 Say Y here if you are working with real-time apps or heavy loads
212 int "Milliseconds to delay boosting after RCU grace-period start"
218 a given grace period before priority-boosting preempted RCU
225 bool "Perform RCU expedited work in a real-time kthread"
233 disable expedited grace periods after boot by unconditionally
239 bool "Offload RCU callback processing from boot-selected CPUs"
245 real-time workloads. It can also be used to offload RCU
246 callback invocation to energy-efficient CPUs in battery-powered
249 workloads will incur significant increases in context-switch
253 CPUs specified at boot time by the rcu_nocbs parameter.
256 and where the "x" is "p" for RCU-preempt (PREEMPTION kernels)
257 and "s" for RCU-sched (!PREEMPTION kernels). This option
267 rcutree.rcu_nocb_gp_stride kernel boot parameter. This can
280 by default, in the absence of the rcu_nocbs or nohz_full boot
281 parameter. This also avoids the need to use any boot parameters
282 to achieve the effect of offloading all CPUs on boot.
284 Say Y here if you want offload all CPUs by default on boot.
288 bool "Offload RCU callback from real-time kthread"
297 it is your responsibility to ensure that latency-sensitive
311 the rcupdate.rcu_task_ipi_delay kernel boot parameter
314 real-time installations and for battery-powered devices,
318 Say N here if you hate read-side memory barriers.
331 Use rcutree.enable_rcu_lazy=0 to turn it off at boot time.
339 off. Boot time param rcutree.enable_rcu_lazy=1 can be used to switch
343 bool "RCU callback-batch backup time check"
350 thus defeating the 32-callback batching used to amortize the
351 cost of the fine-grained but expensive local_clock() function.
353 This option rounds rcutree.rcu_resched_ns up to the next
354 jiffy, and overrides the 32-callback batching if this limit
357 Say Y here if you need tighter callback-limit enforcement.