Section 9.12. RCU Options

9.12. RCU Options

Read Copy Update (RCU) is a portion of the kernel that handles mutual exclusion for a variety of subsystems in a lockless manner. There are a number of options that can be used to tune RCU in different ways:

RCU batch limit.

rcu.blimit= n

Set the maximum number of finished RCU callbacks to process in one batch.

RCU queue high level.

rcu.qhimark= n

Batch limiting is disabled when the number of queued RCU callbacks rises above n.

RCU queue low level.

rcu.qlowmark= n

Batch limiting is re-enabled when the number of queued RCU callbacks falls below n.

RCU callback queue length.

rcu.rsinterval= n

Set the number of additional RCU callbacks that should be queued before forcing a reschedule on all CPUs.