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.
88 task-based RCU implementations. Not for manual selection.
96 This option force-enables a task-based RCU implementation
98 idle, and user-mode execution as quiescent states. Not for
116 This option force-enables a task-based RCU implementation
118 user-mode execution as quiescent states. It forces IPIs and
133 This option enables a task-based RCU implementation that uses
134 explicit rcu_read_lock_trace() read-side markers, and allows
157 int "Tree-based hierarchical RCU fanout value"
169 systems, but if you are stress-testing the RCU implementation
170 itself, small RCU_FANOUT values allow you to test large-system
177 int "Tree-based hierarchical RCU leaf-level fanout value"
185 This option controls the leaf-level fanout of hierarchical
188 scheduling-clock interrupts for energy-efficiency reasons will
189 want the default because the smaller leaf-level fanout keeps
193 number of cache misses incurred during RCU's grace-period
194 initialization. These systems tend to run CPU-bound, and thus
197 leaf-level fanouts work well. That said, setting leaf-level
199 lock contention on the leaf-level rcu_node structures unless
200 you boot with the skew_tick kernel parameter.
206 kernel boot parameter to avoid contention on the rcu_node
221 Say Y here if you are working with real-time apps or heavy loads
225 int "Milliseconds to delay boosting after RCU grace-period start"
231 a given grace period before priority-boosting preempted RCU
238 bool "Perform RCU expedited work in a real-time kthread"
246 disable expedited grace periods after boot by unconditionally
252 bool "Offload RCU callback processing from boot-selected CPUs"
258 real-time workloads. It can also be used to offload RCU
259 callback invocation to energy-efficient CPUs in battery-powered
262 workloads will incur significant increases in context-switch
266 CPUs specified at boot time by the rcu_nocbs parameter.
269 and where the "x" is "p" for RCU-preempt (PREEMPTION kernels)
270 and "s" for RCU-sched (!PREEMPTION kernels). This option
280 rcutree.rcu_nocb_gp_stride kernel boot parameter. This can
293 by default, in the absence of the rcu_nocbs or nohz_full boot
294 parameter. This also avoids the need to use any boot parameters
295 to achieve the effect of offloading all CPUs on boot.
297 Say Y here if you want offload all CPUs by default on boot.
301 bool "Offload RCU callback from real-time kthread"
310 it is your responsibility to ensure that latency-sensitive
324 the rcupdate.rcu_task_ipi_delay kernel boot parameter
327 real-time installations and for battery-powered devices,
331 Say N here if you hate read-side memory barriers.
348 Use the rcutree.enable_rcu_lazy=0 kernel-boot parameter to
357 to boot with these energy-efficiency delays disabled. Use the
358 rcutree.enable_rcu_lazy=0 kernel-boot parameter to override
359 the this option at boot time, thus re-enabling these delays.
362 bool "RCU callback-batch backup time check"
369 thus defeating the 32-callback batching used to amortize the
370 cost of the fine-grained but expensive local_clock() function.
372 This option rounds rcutree.rcu_resched_ns up to the next
373 jiffy, and overrides the 32-callback batching if this limit
376 Say Y here if you need tighter callback-limit enforcement.