rcu: Make expedited RCU-sched grace period immediately detect idle
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tue, 12 Jan 2016 16:33:37 +0000 (08:33 -0800)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Thu, 31 Mar 2016 20:34:03 +0000 (13:34 -0700)
commit28728dd310d48834cd486dac3cac9ae96b9deb96
tree507e605d6e89567f62d8148b779a45d6f369d52e
parent274529ba9bda86c91c2c06da3a641aaf617dd30f
rcu: Make expedited RCU-sched grace period immediately detect idle

Currently, sync_sched_exp_handler() will force a reschedule unless
this CPU has already checked in or unless a reschedule has already
been called for.  This is clearly wasteful if sync_sched_exp_handler()
interrupted an idle CPU, so this commit immediately reports the
quiescent state in that case.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
kernel/rcu/tree.c