[bootlin/training-materials updates] master: kernel-locking: Enable CONFIG_DEBUG_ATOMIC_SLEEP (7ee8d2fd)

[Miquel Raynal]

Repository : https://github.com/bootlin/training-materials
On branch  : master
Link       : https://github.com/bootlin/training-materials/commit/7ee8d2fd1a027a3c8901a8f8bf35b20936f97549

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commit 7ee8d2fd1a027a3c8901a8f8bf35b20936f97549
Author: Miquel Raynal <miquel.raynal at bootlin.com>
Date:   Tue Oct 18 11:01:45 2022 +0200

    kernel-locking: Enable CONFIG_DEBUG_ATOMIC_SLEEP
    
    This will warn the trainees if they use a function that _may_ sleep (but
    does not) in atomic context.
    
    Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>


>---------------------------------------------------------------

7ee8d2fd1a027a3c8901a8f8bf35b20936f97549
 labs/kernel-locking/kernel-locking.tex | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/labs/kernel-locking/kernel-locking.tex b/labs/kernel-locking/kernel-locking.tex
index d5e817f5..97d16ad9 100644
--- a/labs/kernel-locking/kernel-locking.tex
+++ b/labs/kernel-locking/kernel-locking.tex
@@ -13,6 +13,15 @@ Continue to work with the \code{serial} driver.
 
 You need to have completed the previous two labs to perform this one.
 
+On the kernel side, recompile it with the following option:
+
+\begin{itemize}
+\item \kconfig{CONFIG_DEBUG_ATOMIC_SLEEP}: this will allow you to be
+  (loudly) warned if a function which may sleep is called from atomic
+  context, while sleeping is not allowed. Otherwise, in practice, if the
+  function that may sleep does not need to, you might not notice it!
+\end{itemize}
+
 \section{Adding appropriate locking}
 
 We have two shared resources in our driver: