[bootlin/training-materials updates] master: Boot time: toolchain optimization lab (2e98aba8)
Michael Opdenacker
michael.opdenacker at bootlin.com
Tue May 21 07:22:37 CEST 2019
Repository : https://github.com/bootlin/training-materials
On branch : master
Link : https://github.com/bootlin/training-materials/commit/2e98aba8dddecf797beb0fe77b6d9945fbb08fc1
>---------------------------------------------------------------
commit 2e98aba8dddecf797beb0fe77b6d9945fbb08fc1
Author: Michael Opdenacker <michael.opdenacker at bootlin.com>
Date: Tue May 21 07:22:37 2019 +0200
Boot time: toolchain optimization lab
Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>
>---------------------------------------------------------------
2e98aba8dddecf797beb0fe77b6d9945fbb08fc1
.../data/0001-ffmpeg-exit-after-first-frame.patch | 41 +++
labs/boot-time-toolchain/boot-time-toolchain.tex | 145 ++++++++
mk/boot-time.mk | 2 +
slides/boot-time-measuring/boot-time-measuring.tex | 1 +
.../boot-time-references/boot-time-references.tex | 20 ++
.../boot-time-toolchain2/boot-time-toolchain2.tex | 11 +-
slides/boot-time-toolchain2/using-time-command.svg | 366 +++++++++++++++++++++
7 files changed, 585 insertions(+), 1 deletion(-)
diff --git a/lab-data/boot-time/rootfs/data/0001-ffmpeg-exit-after-first-frame.patch b/lab-data/boot-time/rootfs/data/0001-ffmpeg-exit-after-first-frame.patch
new file mode 100644
index 00000000..ede40606
--- /dev/null
+++ b/lab-data/boot-time/rootfs/data/0001-ffmpeg-exit-after-first-frame.patch
@@ -0,0 +1,41 @@
+From 2722d61aaa1f2604b3de5bd581b871c6f9d54d7e Mon Sep 17 00:00:00 2001
+From: Michael Opdenacker <michael.opdenacker at bootlin.com>
+Date: Fri, 17 May 2019 19:41:49 +0200
+Subject: [PATCH] ffmpeg - exit after first frame
+
+This writes to the application log and exits after the first frame
+has been decoded and displayed.
+
+Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>
+---
+ fftools/ffmpeg.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
+index 01f04103cf..e2f8785b7a 100644
+--- a/fftools/ffmpeg.c
++++ b/fftools/ffmpeg.c
+@@ -4659,6 +4659,7 @@ static int transcode(void)
+ InputStream *ist;
+ int64_t timer_start;
+ int64_t total_packets_written = 0;
++ static int framecounter=0;
+
+ ret = transcode_init();
+ if (ret < 0)
+@@ -4696,6 +4697,12 @@ static int transcode(void)
+ }
+
+ /* dump report by using the output first video and audio streams */
++ // Bootlin hack to signal when the first frame has been decoded
++ if (framecounter++==0) {
++ // Log on console and exit
++ av_log(NULL, AV_LOG_INFO, "First frame decoded!\n");
++ exit_program(1);
++ }
+ print_report(0, timer_start, cur_time);
+ }
+ #if HAVE_THREADS
+--
+2.17.1
+
diff --git a/labs/boot-time-toolchain/boot-time-toolchain.tex b/labs/boot-time-toolchain/boot-time-toolchain.tex
new file mode 100644
index 00000000..692bc3d8
--- /dev/null
+++ b/labs/boot-time-toolchain/boot-time-toolchain.tex
@@ -0,0 +1,145 @@
+\subchapter{Toolchain optimization}{Get the best cross-compiling
+toolchain for your application and system}
+
+The goal of this lab is to find the best toolchain for your application,
+in terms of performance and code size. Smaller code can be faster to
+load, and save time when using in an initramfs (when the whole
+filesystem is loaded at once in RAM).
+
+In this lab, we will see how to test an alternative toolchain, measuring:
+\begin{itemize}
+ \item Application execution time
+ \item Application and total filesystem size
+\end{itemize}
+
+\section{Measuring application execution time}
+
+At this stage, measuring the total system boot time is not accurate
+enough. We need to time the execution of the application more precisely.
+
+Hence, we will call the \code{ffmpeg} player directly from the command
+line and temporarily apply a patch that will make \code{ffmpeg}
+exit after processing the first frame.
+
+To achieve this:
+\begin{itemize}
+\item Temporarily replace the
+\code{0001-ffmpeg-log-notification-after-first-frame.patch} patch
+by \code{0001-ffmpeg-exit-after-first-frame.patch} found in
+\code{~/boot-time-labs/rootfs/data/}.
+\item Edit the \code{S50playvideo} script to comment out the line
+starting \code{ffmpeg} automatically.
+\end{itemize}
+
+Now, rebuild the root filesystem:
+\begin{verbatim}
+make ffmpeg-dirclean
+make
+\end{verbatim}
+
+Let's measure the total root filesystem size and the size of the
+\code{ffmpeg} executable:
+
+\begin{verbatim}
+ls -l output/images/rootfs.tar
+tar tvf output/images/rootfs.tar ./usr/bin/ffmpeg
+make
+\end{verbatim}
+
+Write these two numbers in the first row of the below table:
+
+\begin{tabular}{| l | l | r |}
+ \hline
+ & Total rootfs size & \code{/usr/bin/ffmpeg} size \\
+ \hline
+ \hline
+ ARM toolchain & & \\
+ \hline
+ Thumb2 toolchain & & \\
+ \hline
+ Difference (percentage) & & \\
+ \hline
+\end{tabular}
+
+Reflash the root filesystem on the SD card and reboot your board.
+On the serial console, log in and run the video player through the
+\code{time} command (copying and pasting the command from these
+instructions or from the \code{/etc/init.d/S50playvideo} file:
+
+\begin{verbatim}
+time ffmpeg -t 10 -f video4linux2 -video_size 544x288 -input_format mjpeg \
+-i /dev/video0 -pix_fmt rgb565le -f fbdev /dev/fb0
+\end{verbatim}
+
+Write down your first results in the below table (\code{total1},
+\code{user1} and \code{sys1} columns):
+
+\begin{tabular}{| l | l | l | l || l | l | l || l | l | l |}
+ \hline
+ & total1 & user1 & sys1 & total2 & user2 & sys2 & total3 & user3 & sys3 \\
+ \hline
+ \hline
+ ARM toolchain & & & & & & & & & \\
+ \hline
+ Thumb2 toolchain & & & & & & & & & \\
+ \hline
+\end{tabular}
+
+After the first run, the program and its shared libraries are now in the
+file cache. Lets run the command two more times and write down (in the
+\code{2} and \code{3} columns) how fast it can run in this ideal case.
+
+\section{Switching to a Thumb2 toolchain}
+
+Now, let's modify the Buildroot toolchain, so that it generates {\em
+Thumb2} code (instead of {\em ARM}) by default.
+
+Before we switch, let's make a backup of the \code{buildroot} directory,
+in case results are disappointing and we wish to revert the changes without
+having to go through a full build again. In our particular case, we will
+start the next lab using this backup, waiting for the new build to be
+complete.
+
+In case you didn't know, a time and disk space efficient way to do this is by using the
+\code{cp -al} command, which uses hard links instead of making new copies
+of each file:
+
+\begin{verbatim}
+cd ..
+cp -al buildroot buildroot-arm
+\end{verbatim}
+
+You can then check that the files correspond to the same inode:
+\begin{verbatim}
+ls -i buildroot/Makefile buildroot-arm/Makefile
+\end{verbatim}
+
+Back to the \code{buildroot} directory, run \code{make menuconfig}, and
+in \code{Target options}, set \code{ARM instruction set} to
+\code{Thumb2}.
+
+Save the changes and run the full toolchain and root filesystem build
+again:
+
+\begin{verbatim}
+make clean
+make
+\end{verbatim}
+
+This is probably going to run for at least 30 minutes. In the meantime,
+start working on the next lab.
+
+When the build is over:
+\begin{itemize}
+\item Measure the new rootfilesystem archive and \code{ffmpeg}
+executable size, write it down in the table, and compute the difference
+percentages vs. the ARM code.
+\item Update the SD card with the new filesystem, run the same time
+measurements, and write down the results to compare them with the ARM
+ones.
+\end{itemize}
+
+So, was it a good choice to switch to {\em Thumb2}? Where there any size
+and performance benefits?
+
+Don't hesitate to show your results to your instructor.
diff --git a/mk/boot-time.mk b/mk/boot-time.mk
index 753c17b2..c6f06ade 100644
--- a/mk/boot-time.mk
+++ b/mk/boot-time.mk
@@ -24,6 +24,7 @@ BOOT_TIME_SLIDES = \
boot-time-kernel \
boot-time-bootloader \
boot-time-hardware-init \
+ boot-time-references \
BOOT_TIME_LABS = boot-time-goals \
setup \
@@ -33,6 +34,7 @@ BOOT_TIME_LABS = boot-time-goals \
boot-time-build-bootloader \
boot-time-build-kernel-and-start-system \
boot-time-software-measurement \
+ boot-time-toolchain \
boot-time-application \
boot-time-init-scripts \
boot-time-kernel \
diff --git a/slides/boot-time-measuring/boot-time-measuring.tex b/slides/boot-time-measuring/boot-time-measuring.tex
index f4df3568..1ea00545 100644
--- a/slides/boot-time-measuring/boot-time-measuring.tex
+++ b/slides/boot-time-measuring/boot-time-measuring.tex
@@ -130,6 +130,7 @@ was received at that time.}
\frametitle{Dedicated measuring resources}
Later, we will see specific resources for measuring time
\begin{itemize}
+ \item \code{time} for measuring application time
\item \code{strace} for application tracing
\item \code{bootchartd} for tracing the execution of system services
\item \code{CONFIG_PRINTK_TIME} and \code{initcall_debug} for
diff --git a/slides/boot-time-references/boot-time-references.tex b/slides/boot-time-references/boot-time-references.tex
new file mode 100644
index 00000000..ebf1b112
--- /dev/null
+++ b/slides/boot-time-references/boot-time-references.tex
@@ -0,0 +1,20 @@
+\section{References}
+
+\begin{frame}
+\frametitle{Conference presentations}
+\begin{itemize}
+\item Andrew Murray - The Right Approach to Minimal Boot Time (2010) \\
+ Video: \url{https://frama.link/nrf696Hy}\\
+ Slides: \url{https://frama.link/uCBH9jQM} \\
+ Great talk about the methodology.
+\item Chris Simmonds - A Pragmatic Guide to Boot-Time Optimization (2017)\\
+ Video: \url{https://youtu.be/gIK1he6Ocpg}\\
+ Slides: \url{https://frama.link/TC0YKM9N}
+\item Jan Altenberg - How to Boot Linux in One Second (2015)\\
+ Video: \url{https://youtu.be/KTRA1PRJWH8}
+ Slides: \url{https://frama.link/bFkvgLFR}
+\item Michael Opdenacker - Embedded Linux size reduction techniques (2017)
+ Video: \url{https://youtu.be/ynNLlzOElOU}
+ Slides: \url{https://frama.link/fS5gQZZq}
+\end{itemize}
+\end{frame}
diff --git a/slides/boot-time-toolchain2/boot-time-toolchain2.tex b/slides/boot-time-toolchain2/boot-time-toolchain2.tex
index 87ccef97..d4dfd407 100644
--- a/slides/boot-time-toolchain2/boot-time-toolchain2.tex
+++ b/slides/boot-time-toolchain2/boot-time-toolchain2.tex
@@ -1,3 +1,11 @@
+\begin{frame}
+\frametitle{Time your commands using the time command}
+\begin{center}
+\includegraphics[height=0.7\textheight]{slides/boot-time-toolchain2/using-time-command.pdf}
+\end{center}
+This gives you the best time that can possibly be achieved (with the fastest storage).
+\end{frame}
+
\setuplabframe {Trying a Thumb2 toolchain}
{
\begin{itemize}
@@ -8,6 +16,7 @@
\end{itemize}
}
+
\begin{frame}
\frametitle{Lessons from labs: ARM vs Thumb2}
\begin{itemize}
@@ -32,7 +41,7 @@ class)}\\
Tried to replace {\em uClibc} by {\em musl} in our video player lab:
\begin{itemize}
- \item musl library size: 680 KB (size of the \code{lib/} \code{tar} archive)
+ \item musl library size: 680 KB (size of the \code{tar} archive for \code{lib/})
\item uClibc library size: 570 KB
\item uClibc saves 110 KB (useful), but otherwise no other significant change
in filesystem and code size. Not a surprise when the system is mostly filled
diff --git a/slides/boot-time-toolchain2/using-time-command.svg b/slides/boot-time-toolchain2/using-time-command.svg
new file mode 100644
index 00000000..c01147c6
--- /dev/null
+++ b/slides/boot-time-toolchain2/using-time-command.svg
@@ -0,0 +1,366 @@
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+ x="12.851191"
+ y="109.03167"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.81944466px;font-family:'Courier 10 Pitch';-inkscape-font-specification:'Courier 10 Pitch, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.26458332px"
+ id="tspan843">> time ffmpeg...</tspan><tspan
+ sodipodi:role="line"
+ x="12.851191"
+ y="120.21642"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.81944466px;font-family:'Courier 10 Pitch';-inkscape-font-specification:'Courier 10 Pitch, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.26458332px"
+ id="tspan825">real 0m 0.66s</tspan><tspan
+ sodipodi:role="line"
+ x="12.851191"
+ y="131.40117"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.81944466px;font-family:'Courier 10 Pitch';-inkscape-font-specification:'Courier 10 Pitch, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.26458332px"
+ id="tspan827">user 0m 0.17s</tspan><tspan
+ sodipodi:role="line"
+ x="12.851191"
+ y="142.58592"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.81944466px;font-family:'Courier 10 Pitch';-inkscape-font-specification:'Courier 10 Pitch, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.26458332px"
+ id="tspan829">sys 0m 0.25s</tspan><tspan
+ sodipodi:role="line"
+ x="12.851191"
+ y="153.77068"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.81944466px;font-family:'Courier 10 Pitch';-inkscape-font-specification:'Courier 10 Pitch, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.26458332px"
+ id="tspan835" /><tspan
+ sodipodi:role="line"
+ x="12.851191"
+ y="164.79498"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.81944466px;font-family:sans-serif;-inkscape-font-specification:'sans-serif, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.26458332px"
+ id="tspan837">real = user + sys + waiting time</tspan></text>
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="12.533006"
+ y="24.812538"
+ id="text841"><tspan
+ sodipodi:role="line"
+ id="tspan839"
+ x="12.533006"
+ y="24.812538"
+ style="fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-opacity:1">First run</tspan></text>
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="12.817226"
+ y="95.986916"
+ id="text841-7"><tspan
+ sodipodi:role="line"
+ id="tspan839-4"
+ x="12.817226"
+ y="95.986916"
+ style="fill:#000000;fill-opacity:1;stroke-width:0.26458332px">Second run (program and librairies already in file cache)</tspan></text>
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="112.79565"
+ y="64.267433"
+ id="text841-4"><tspan
+ sodipodi:role="line"
+ x="112.79565"
+ y="64.267433"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:7.05555534px;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;fill:#ca0b0b;fill-opacity:1;stroke-width:0.26458332px"
+ id="tspan881">Time in userspace (running the program and shared libs)</tspan></text>
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="112.79565"
+ y="74.701973"
+ id="text841-4-6"
+ inkscape:transform-center-x="6.1471991"
+ inkscape:transform-center-y="-18.708867"><tspan
+ sodipodi:role="line"
+ x="112.79565"
+ y="74.701973"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:7.05555534px;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;fill:#ca0b0b;fill-opacity:1;stroke-width:0.26458332px"
+ id="tspan881-8">Time in kernel space (accessing files, accessing device data)</tspan></text>
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="112.79565"
+ y="53.560822"
+ id="text841-4-4"><tspan
+ sodipodi:role="line"
+ x="112.79565"
+ y="53.560822"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:7.05555534px;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;fill:#ca0b0b;fill-opacity:1;stroke-width:0.26458332px"
+ id="tspan881-89">Total observed time</tspan></text>
+ <path
+ style="fill:none;fill-rule:evenodd;stroke:#ca0b0b;stroke-width:1;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;marker-end:url(#Arrow1Mstart)"
+ d="m 107.17508,51.646573 c -16.837981,0 -17.10525,0 -17.10525,0 v 0"
+ id="path921"
+ inkscape:connector-curvature="0" />
+ <path
+ style="fill:none;fill-rule:evenodd;stroke:#ca0b0b;stroke-width:1;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;marker-end:url(#Arrow1Mstart-8)"
+ d="m 106.5568,62.497183 c -16.837977,0 -17.105246,0 -17.105246,0 v 0"
+ id="path921-7"
+ inkscape:connector-curvature="0" />
+ <path
+ style="fill:none;fill-rule:evenodd;stroke:#ca0b0b;stroke-width:1;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;marker-end:url(#Arrow1Mstart-8-0)"
+ d="m 106.5568,73.080523 c -16.837975,0 -17.105244,0 -17.105244,0 v 0"
+ id="path921-7-1"
+ inkscape:connector-curvature="0" />
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="108.51142"
+ y="173.52148"
+ id="text1893"><tspan
+ sodipodi:role="line"
+ id="tspan1891"
+ x="108.51142"
+ y="181.32463"
+ style="stroke-width:0.26458332px" /></text>
+ <path
+ style="fill:none;fill-rule:evenodd;stroke:#ca0b0b;stroke-width:1;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;marker-start:url(#marker3024);marker-end:url(#Arrow1Mstart-1)"
+ d="m 87.3134,171.73531 -42.228587,-0.26727 v 0"
+ id="path921-8"
+ inkscape:connector-curvature="0"
+ sodipodi:nodetypes="ccc" />
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="12.805789"
+ y="183.17181"
+ id="text841-4-4-2"><tspan
+ sodipodi:role="line"
+ x="12.805789"
+ y="183.17181"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:7.05555534px;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;fill:#ca0b0b;fill-opacity:1;stroke-width:0.26458332px"
+ id="tspan881-89-9">Your program cannot run faster than user + sys (unless you optimize the code)</tspan></text>
+ <text
+ xml:space="preserve"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:8.8194437px;line-height:125%;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1"
+ x="112.78773"
+ y="119.57751"
+ id="text841-4-4-9"><tspan
+ sodipodi:role="line"
+ x="112.78773"
+ y="119.57751"
+ style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:7.05555534px;font-family:Sans;-inkscape-font-specification:'Sans, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;fill:#ca0b0b;fill-opacity:1;stroke-width:0.26458332px"
+ id="tspan881-89-4">Less waiting time!</tspan></text>
+ <path
+ style="fill:none;fill-rule:evenodd;stroke:#ca0b0b;stroke-width:1;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1;marker-end:url(#Arrow1Mstart-6)"
+ d="m 107.16717,117.66326 c -16.837981,0 -17.10525,0 -17.10525,0 v 0"
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+ </g>
+</svg>
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