Preemptible RCU

modulename: rcupreempt.ko

configname: CONFIG_PREEMPT_RCU

Linux Kernel Configuration
└─>Preemptible RCU
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
This option reduces the latency of the kernel by making certain
RCU sections preemptible. Normally RCU code is non-preemptible, if
this option is selected then read-only RCU sections become
preemptible. This helps latency, but may expose bugs due to
now-naive assumptions about each RCU read-side critical section
remaining on a given CPU through its execution.

Say N if you are unsure.

source code:
depends
CONFIG_PREEMPT

is selected by
CONFIG_RCU_TRACE