Commit 71de1e34 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

doc: Document the rcutree.rcu_divisor kernel boot parameter 



This commit adds kernel-parameters.txt documentation for the
rcutree.rcu_divisor kernel boot parameter, which controls the softirq
callback-invocation batch limit.

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarNeeraj Upadhyay <quic_neeraju@quicinc.com>
parent cb506e13

Documentation/admin-guide/kernel-parameters.txt

+15 −0
Original line number Diff line number Diff line
@@ -4666,6 +4666,21 @@ 
			When RCU_NOCB_CPU is set, also adjust the

			priority of NOCB callback kthreads.



	rcutree.rcu_divisor= [KNL]

			Set the shift-right count to use to compute

			the callback-invocation batch limit bl from

			the number of callbacks queued on this CPU.

			The result will be bounded below by the value of

			the rcutree.blimit kernel parameter.  Every bl

			callbacks, the softirq handler will exit in

			order to allow the CPU to do other work.



			Please note that this callback-invocation batch

			limit applies only to non-offloaded callback

			invocation.  Offloaded callbacks are instead

			invoked in the context of an rcuoc kthread, which

			scheduler will preempt as it does any other task.



	rcutree.rcu_nocb_gp_stride= [KNL]

			Set the number of NOCB callback kthreads in

			each group, which defaults to the square root