Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 526914a0 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Paul E. McKenney
Browse files

doc: Fix RCU requirements typos 



Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent e73c14eb

Documentation/RCU/Design/Requirements/Requirements.html

+6 −6
Original line number Diff line number Diff line
@@ -1480,7 +1480,7 @@ speed-of-light delays if nothing else. 


<p>

Furthermore, uncertainty about external state is inherent in many cases.

For example, a pair of veternarians might use heartbeat to determine

For example, a pair of veterinarians might use heartbeat to determine

whether or not a given cat was alive.

But how long should they wait after the last heartbeat to decide that

the cat is in fact dead?
@@ -1489,9 +1489,9 @@ mean that a relaxed cat would be considered to cycle between death 
and life more than 100 times per minute.

Moreover, just as with human beings, a cat's heart might stop for

some period of time, so the exact wait period is a judgment call.

One of our pair of veternarians might wait 30 seconds before pronouncing

One of our pair of veterinarians might wait 30 seconds before pronouncing

the cat dead, while the other might insist on waiting a full minute.

The two veternarians would then disagree on the state of the cat during

The two veterinarians would then disagree on the state of the cat during

the final 30 seconds of the minute following the last heartbeat.



<p>
@@ -1945,7 +1945,7 @@ guard against mishaps and misuse: 
<ol>

<li>	It is all too easy to forget to use <tt>rcu_read_lock()</tt>

	everywhere that it is needed, so kernels built with

	<tt>CONFIG_PROVE_RCU=y</tt> will spat if

	<tt>CONFIG_PROVE_RCU=y</tt> will splat if

	<tt>rcu_dereference()</tt> is used outside of an

	RCU read-side critical section.

	Update-side code can use <tt>rcu_dereference_protected()</tt>,
@@ -2421,7 +2421,7 @@ However, there are some restrictions on the code placed within 
<li>	Blocking is prohibited.

	In practice, this is not a serious restriction given that idle

	tasks are prohibited from blocking to begin with.

<li>	Although nesting <tt>RCU_NONIDLE()</tt> is permited, they cannot

<li>	Although nesting <tt>RCU_NONIDLE()</tt> is permitted, they cannot

	nest indefinitely deeply.

	However, given that they can be nested on the order of a million

	deep, even on 32-bit systems, this should not be a serious
@@ -2885,7 +2885,7 @@ APIs for defining and initializing <tt>srcu_struct</tt> structures. 
<h3><a name="Tasks RCU">Tasks RCU</a></h3>



<p>

Some forms of tracing use &ldquo;tramopolines&rdquo; to handle the

Some forms of tracing use &ldquo;trampolines&rdquo; to handle the

binary rewriting required to install different types of probes.

It would be good to be able to free old trampolines, which sounds

like a job for some form of RCU.