RCU_READ_LOCK_BH_HEL(9)                   Driver Basics                   RCU_READ_LOCK_BH_HEL(9)



NAME
       rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section?

SYNOPSIS
       int rcu_read_lock_bh_held(void);

ARGUMENTS
       void
           no arguments

DESCRIPTION
       Check for bottom half being disabled, which covers both the CONFIG_PROVE_RCU and not
       cases. Note that if someone uses rcu_read_lock_bh, but then later enables BH, lockdep (if
       enabled) will show the situation. This is useful for debug checks in functions that
       require that they be called within an RCU read-side critical section.

       Check debug_lockdep_rcu_enabled to prevent false positives during boot.

       Note that rcu_read_lock is disallowed if the CPU is either idle or offline from an RCU
       perspective, so check for those as well.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   RCU_READ_LOCK_BH_HEL(9)