[FE training-materials-updates] RT slides: remove the big "Real-time approaches" slide

Michael Opdenacker michael.opdenacker at free-electrons.com
Tue Nov 12 10:09:00 CET 2013


Repository : git://git.free-electrons.com/training-materials.git

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=164fcd65f5efbbd92f8eee8e6ff681ac86937406

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

commit 164fcd65f5efbbd92f8eee8e6ff681ac86937406
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date:   Tue Nov 12 09:59:21 2013 +0100

    RT slides: remove the big "Real-time approaches" slide
    
    - Very difficult to explain as it is covers many approaches
      which aren't event mentioned in our presentation.
    
    - This slide looked very "disconnected" from the rest of the
      presentation.
    
    - If we decided to keep it as conclusion, it would be best
      to conclude by only showing comparisons between Xenomai and PREEMPT_RT
      on the same hardware.
    
    Signed-off-by: Michael Opdenacker <michael.opdenacker at free-electrons.com>


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

164fcd65f5efbbd92f8eee8e6ff681ac86937406
 slides/sysdev-realtime/sysdev-realtime.tex |   46 ++++++++++------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/slides/sysdev-realtime/sysdev-realtime.tex b/slides/sysdev-realtime/sysdev-realtime.tex
index b893c26..45551da 100644
--- a/slides/sysdev-realtime/sysdev-realtime.tex
+++ b/slides/sysdev-realtime/sysdev-realtime.tex
@@ -413,6 +413,22 @@
   \end{itemize}
 \end{frame}
 
+\begin{frame}
+  \frametitle{The future of the PREEMPT\_RT patchset}
+  Conclusion of the Realtime Linux minisummit (Nov. 2013):
+  \begin{itemize}
+  \item {\em The PREEMPT\_RT project will be done in 2014, "one way or another".
+        The first way would be to get most of the rest of the code upstream, but
+        that will require more of an effort, from a wider group than is
+        currently involved. The alternative is to decide that the 95\% of the
+        realtime work already upstream is good enough and to drop further
+        efforts.} 
+  \item Main issue: lack of companies devoting enough engineering
+        resources to complete the job. 
+  \item See \url{http://lwn.net/Articles/572740/}
+  \end{itemize}
+\end{frame}
+
 \subsection{PREEMPT\_RT specifics}
 
 \begin{frame}
@@ -1370,36 +1386,6 @@ ARCH-gcc $CFL -o rttest rttest.c $LDF
 \end{frame}
 
 \begin{frame}
-  \frametitle{Real-time approaches} The following table is Paul Mac
-  Kenney's summary of his own article describing the various
-  approaches for real-time on Linux:\\
-  \vspace{0.3cm}
-  \tiny
-  \begin{tabular}{|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|}
-    \hline
-    {\bf Approach} & {\bf Quality} & {\bf Inspection} & {\bf API} & {\bf Complexity} & {\bf Fault isolation} & {\bf HW/SW config} \\
-    \hline
-    Vanilla Linux & 10s of ms, all services & All & POSIX+RT & N/A & None & All \\
-    \hline
-    PREEMPT & 100s of us, sched, int & preempt or irq disable & POSIX+RT & N/A & None & All \\
-    \hline
-    Nested OS (co-kernel) & around 10us, RTOS services & RTOS, hw irq disable & RTOS (can be POSIX RT) & Dual env. & Good & All \\
-    \hline
-    Dual-OS/Dual-Core (ASMP) & less than 1us, RTOS serivces & RTOS & RTOS (can be POSIX RT) & Dual Env. & Excellent & Specialized \\
-    \hline
-    PREEMPT\_RT & 10s of us, sched, int & preempt and irq disable (most ints in process context) & POSIX+RT & {\em Modest} patch & None & All (except some drivers) \\
-    \hline
-    Migration between OSes & ? us, RTOS services & RTOS, hw irq disable & RTOS (can be POSIX RT) & Dual env. & OK & All \\
-    \hline
-    Migration within OS & ? us, RTOS services & Sched, RTOS services & POSIX+RT & Small patch & None & All? \\
-    \hline
-  \end{tabular}\\
-  \vspace{0.3cm}
-  \normalsize
-  Full story at \url{http://lwn.net/Articles/143323}
-\end{frame}
-
-\begin{frame}
   \frametitle{Books}
   \begin{columns}[T]
     \column{0.8\textwidth}



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