From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Wed, 15 Dec 2010 01:36:02 +0000 (-0800)
Subject: rcu: reduce __call_rcu()-induced contention on rcu_node structures
X-Git-Tag: v2.6.38-rc1~492^2^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b52573d2796274f7f31cfeff7185c320adcd4f12;p=pandora-kernel.git

rcu: reduce __call_rcu()-induced contention on rcu_node structures

When the current __call_rcu() function was written, the expedited
APIs did not exist.  The __call_rcu() implementation therefore went
to great lengths to detect the end of old grace periods and to start
new ones, all in the name of reducing grace-period latency.  Now the
expedited APIs do exist, and the usage of __call_rcu() has increased
considerably.  This commit therefore causes __call_rcu() to avoid
worrying about grace periods unless there are a large number of
RCU callbacks stacked up on the current CPU.

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

Reading git-diff-tree failed