From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Wed, 22 May 2013 09:41:36 +0000 (-0700)
Subject: trace: Allow idle-safe tracepoints to be called from irq
X-Git-Tag: v3.10-rc6~13^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d62840995a99c9766803d54e9d7923f247a1c1db;p=pandora-kernel.git

trace: Allow idle-safe tracepoints to be called from irq

__DECLARE_TRACE_RCU() currently creates an _rcuidle() tracepoint which
may safely be invoked from what RCU considers to be an idle CPU.
However, these _rcuidle() tracepoints may -not- be invoked from the
handler of an irq taken from idle, because rcu_idle_enter() zeroes
RCU's nesting-level counter, so that the rcu_irq_exit() returning to
idle will trigger a WARN_ON_ONCE().

This commit therefore substitutes rcu_irq_enter() for rcu_idle_exit()
and rcu_irq_exit() for rcu_idle_enter() in order to make the _rcuidle()
tracepoints usable from irq handlers as well as from process context.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
---

Reading git-diff-tree failed