tree 1155e2ed10709b9d3efa87b2f4b826cc886e84eb
parent d117c8aa1d511f76401337620b9c4ffb4c886579
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1446278341 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1449536491 -0800

rcu: Don't redundantly disable irqs in rcu_irq_{enter,exit}()

This commit replaces a local_irq_save()/local_irq_restore() pair with
a lockdep assertion that interrupts are already disabled.  This should
remove the corresponding overhead from the interrupt entry/exit fastpaths.

This change was inspired by the fact that Iftekhar Ahmed's mutation
testing showed that removing rcu_irq_enter()'s call to local_ird_restore()
had no effect, which might indicate that interrupts were always enabled
anyway.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>