From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Thu, 31 Mar 2016 18:00:08 +0000 (-0700)
Subject: documentation: Emphasize the call_rcu() is illegal from idle
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0c7d10e4b998b2f751cebf98435f1ec2dd312c87;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

documentation: Emphasize the call_rcu() is illegal from idle

Although call_rcu()'s fastpath works just fine on an idle CPU,
some branches of the slowpath invoke the scheduler, which uses
RCU.  Therefore, this commit emphasizes the fact that call_rcu()
must not be invoked from an idle CPU.

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

diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html
index 85cf2238fd08..e7e24b3e86e2 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.html
+++ b/Documentation/RCU/Design/Requirements/Requirements.html
@@ -1650,7 +1650,7 @@ situations where neither <tt>synchronize_rcu()</tt> nor
 including within preempt-disable code, <tt>local_bh_disable()</tt> code,
 interrupt-disable code, and interrupt handlers.
 However, even <tt>call_rcu()</tt> is illegal within NMI handlers
-and from offline CPUs.
+and from idle and offline CPUs.
 The callback function (<tt>remove_gp_cb()</tt> in this case) will be
 executed within softirq (software interrupt) environment within the
 Linux kernel,