616c310e83b872024271c915c1b9ab505b9efad9 - arm/linux

commit	616c310e83b872024271c915c1b9ab505b9efad9	[log] [tgz]
author	Paul E. McKenney <paul.mckenney@linaro.org>	Tue Mar 27 16:02:08 2012 -0700
committer	Paul E. McKenney <paulmck@linux.vnet.ibm.com>	Wed May 02 14:43:23 2012 -0700
tree	1339bc7b3bef920b4641a5af2f182e9dfa2a6632
parent	66f75a5d028beaf67c931435fdc3e7823125730c [diff]

rcu: Move PREEMPT_RCU preemption to switch_to() invocation

Currently, PREEMPT_RCU readers are enqueued upon entry to the scheduler.
This is inefficient because enqueuing is required only if there is a
context switch, and entry to the scheduler does not guarantee a context
switch.

The commit therefore moves the enqueuing to immediately precede the
call to switch_to() from the scheduler.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/drivers/mconsole_kern.c[diff]
include/linux/rcupdate.h[diff]
include/linux/rcutiny.h[diff]
include/linux/sched.h[diff]
kernel/rcutree.c[diff]
kernel/rcutree.h[diff]
kernel/rcutree_plugin.h[diff]
kernel/sched/core.c[diff]

8 files changed

tree: 1339bc7b3bef920b4641a5af2f182e9dfa2a6632