[FE training-materials-updates] Boot time slides: add 'quiet' measurements
Michael Opdenacker
michael.opdenacker at free-electrons.com
Mon Apr 21 18:34:41 CEST 2014
Repository : git://git.free-electrons.com/training-materials.git
On branch : master
Link : http://git.free-electrons.com/training-materials/commit/?id=a7982fc7f735eaa28df2f781290c4209e76c5737
>---------------------------------------------------------------
commit a7982fc7f735eaa28df2f781290c4209e76c5737
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date: Mon Apr 21 14:46:07 2014 +0200
Boot time slides: add 'quiet' measurements
Signed-off-by: Michael Opdenacker <michael.opdenacker at free-electrons.com>
>---------------------------------------------------------------
a7982fc7f735eaa28df2f781290c4209e76c5737
slides/boottime-kernel/boottime-kernel.tex | 29 +++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/slides/boottime-kernel/boottime-kernel.tex b/slides/boottime-kernel/boottime-kernel.tex
index 84dccbc..dd13798 100644
--- a/slides/boottime-kernel/boottime-kernel.tex
+++ b/slides/boottime-kernel/boottime-kernel.tex
@@ -143,13 +143,26 @@ Conclusion: don't use LZO for now.
\end{frame}
\begin{frame}
-\frametitle{Tuning the command line}
+\frametitle{Turning off console output}
\begin{itemize}
- \item The console output is actually taking a lot of time. You
- probably don't need it in production. It can be disabled by
- passing the \code{quiet} argument on the kernel command line.
- You will still be able to use \code{dmesg} to get the
- messages.
+\item Console output is actually taking a lot of time. You
+ probably don't need it in production. It can be disabled by
+ passing the \code{quiet} argument on the kernel command line.
+\item You will still be able to use \code{dmesg} to get the kernel
+ messages.
+\item Time to start the \code{init} program, on Atmel
+ SAMA5D3 Xplained (ARM), Linux 3.10:
+ \newline\newline
+ \begin{tabular}{| l || c | c | c |}
+ \hline
+ & Time & Diff \\
+ \hline
+ Without \code{quiet} & 20.380 s & \\
+ With \code{quiet} & 19.308 s & -1.072 s\\
+ \hline
+ \end{tabular}
+ \newline
+\item Less time will be saved on a reduced kernel, of course.
\end{itemize}
\end{frame}
@@ -174,7 +187,8 @@ Calibrating delay loop... 262.96 BogoMIPS (lpj=1314816)
Calibrating delay loop (skipped) preset value.. 262.96 BogoMIPS (lpj=1314816)
\end{verbatim}
\end{block}
- \item Tests on the Atmel SAMA5D3 Xplained (ARM), Linux 3.10:
+ \item Tests on Atmel SAMA5D3 Xplained (ARM), Linux 3.10:
+ \newline\newline
\begin{tabular}{| l || c | c | c |}
\hline
& Time & Diff \\
@@ -183,6 +197,7 @@ Calibrating delay loop (skipped) preset value.. 262.96 BogoMIPS (lpj=1314816)
With \code{lpj} & 8 ms & -63 ms\\
\hline
\end{tabular}
+ \newline
\item This calculation was longer before 2.6.39 (about 200 ms).
\end{itemize}
\end{frame}
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