rcu: Clean up flavor-related definitions and comments in Kconfig

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2018-07-07 18:12:26 -07:00
parent df8561a0d7
commit 8c1cf2da6f

View File

@ -196,7 +196,7 @@ config RCU_BOOST
This option boosts the priority of preempted RCU readers that
block the current preemptible RCU grace period for too long.
This option also prevents heavy loads from blocking RCU
callback invocation for all flavors of RCU.
callback invocation.
Say Y here if you are working with real-time apps or heavy loads
Say N here if you are unsure.
@ -225,15 +225,15 @@ config RCU_NOCB_CPU
callback invocation to energy-efficient CPUs in battery-powered
asymmetric multiprocessors.
This option offloads callback invocation from the set of
CPUs specified at boot time by the rcu_nocbs parameter.
For each such CPU, a kthread ("rcuox/N") will be created to
invoke callbacks, where the "N" is the CPU being offloaded,
and where the "p" for RCU-preempt and "s" for RCU-sched.
Nothing prevents this kthread from running on the specified
CPUs, but (1) the kthreads may be preempted between each
callback, and (2) affinity or cgroups can be used to force
the kthreads to run on whatever set of CPUs is desired.
This option offloads callback invocation from the set of CPUs
specified at boot time by the rcu_nocbs parameter. For each
such CPU, a kthread ("rcuox/N") will be created to invoke
callbacks, where the "N" is the CPU being offloaded, and where
the "p" for RCU-preempt (PREEMPT kernels) and "s" for RCU-sched
(!PREEMPT kernels). Nothing prevents this kthread from running
on the specified CPUs, but (1) the kthreads may be preempted
between each callback, and (2) affinity or cgroups can be used
to force the kthreads to run on whatever set of CPUs is desired.
Say Y here if you want to help to debug reduced OS jitter.
Say N here if you are unsure.