Computer Systemen 2015: Labbook

October 12, 2015

Looked at the code provide in the directory opt from the Code Examples. There are two files called simd (simd_eq and simd_eq), but they contain no main. Also the files lsb-O1.c lpb-O1.c, ipb-O1.c, fpb-O1.c, fpb-O2.c and dpb-O1.c and dpb-O2.c contain references to simd_v*_combine.
simd_eg and simd_eq calculate the inner product of the SSE vector, only difference is that eg uses a long int i as counter (while eq uses int i).
lsb-O1.c is just a copy of combine.c. combine.c is used to create the executable lsbench, which is accessed with the command MULTIRUN (./multirun.pl -n $(RUNCNT) -p $(RUNPOS), with RUNPOS = 0.8 and RUNCNT = 50).
The command gcc -g -Wall -I. -I../include -mavx2 -mfma -m64 -O1 -DSUM -DLONG -c simd_eg.c works fine (with gcc v4.8.1 on nb-ros), also without the presence of a ../include directory.
simd_v4 is the solution for Problem 1, simd_v4a is the solution of Problem 2. The code for Problem 3-5 is not given.
Made a tar-file, but this one doesn't work on acheron (option -mavx2 not known). On nb-ros this option is known, but running the bench gives an error.
Inspected /proc/cpuinfo. nb-ros has avx (but not avx2), acheron has sse4_1 as max. Changing the level to -mavx solves this for nb-ros. Changing the level to -msse2, -msse3 or -msse4 doesn't work for acheron. Solution was to remove the -mfma flag.
With the -msse4 flag the performance increase is not as large as with the -mavx flag.

Making the practice questions from colorado. Had to add -std=c99 to the Makefiles. The Makefile in if-then-else is missing the file for-loop-bounds.c. Commented this file out of the Makefile.

Moded our HTC Wildfire S (Marvel) Android phone with CyanogenMod 11.
Following this instruction, I went to htcdev and received a code to unlock and modify my bootloader.
First replaced the recovery plugin in my bootloader with the official ClockWorkMod recovery 5.0.2.8, but later found out that I needed a more modern version (6.0.5.0) from the same developer Olivier as the CyanogenMod 11 version for Marvel.
Installed that recovery.img with command fastboot flash recovery.imp.
Rooted the phone by starting recovery with command adb reboot recovery (alternative, power + volume down to start-up after shutdown). Did install from zip -> root.zip. Downloaded in PlayStore SuperUS and let this app update the binary (via the recovery).
Downloaded cm-11-20150308-NIGHTLY-marvel.zip and copied that to the phone with command adb push cm-11-20150308-NIGHTLY-marvel.zip /sdcard/. Did the same with Gapps-light (Gapps-KK-4.4.0).
Performed all wipes from recovery menu, followed by install from zip (both cm-11 and Gapps). Reboot (patience, boot screen was only gone after several minutes) and the HTC Wildfire had Andriod 4.4.0 (KitKat).

Made new bombs with command ./makebomb.pl -i 1 -s ./src -b ./bombs -l CS2015 -u group1@fnwi -v group1. Got the following warnings:gcc -Wall -O1 -DSERVER_NAME=\"tunis.science.uva.nl\" -DSERVER_PORT=15214 -c driverlib.c driverlib.c: In function âlencodeâdriverlib.c:136: warning: pointer targets in passing argument 1 of ârlenâiffer in signedness /usr/include/string.h:399: note: expected ânst char *âut argument is of type âsigned char *âriverlib.c: In function âbmitrâdriverlib.c:243: warning: pointer targets in passing argument 1 of âlencodeâiffer in signedness driverlib.c:134: note: expected âsigned char *âut argument is of type âar *âriverlib.c:243: warning: pointer targets in passing argument 2 of âlencodeâiffer in signedness driverlib.c:134: note: expected âsigned char *âut argument is of type âar *âA. Luckily the other source didn't give any warnings.

Could not download Player 7 under Linux, because I had downloaded that version already from Windows. Downloaded VMware Workstation 11 instead.
I had also a Workstation 10 bundle. Started VMware Player 7.1.0.
Creating a VM from scratch again (same Ubuntu iso).
Could not install gcc-2.95, binutils or valgrind.
Instead, started with sudo apt-get install build-essential manpages-dev.
Followed the instructions from BscKI_y1. Skipped:
sudo aptitude install r-base sudo aptitude install dia sudo aptitude install pspp sudo aptitude install apache2 sudo aptitude install mysql-server php5-mysql sudo aptitude install php5 libapache2-mod-php5 php5-mcrypt php5-cli sudo aptitude install phpmyadmin Also skipped everything after # install Adobe AIR 2.6.
As only addition, I also installed valgrind (version 3.10). binutils is already installed, gcc-2.95 seems to be impossible to install on modern distributions.
Checked what a puzzle should contain, and that are the files README bits.c bits.h decl.c tests.c Makefile btest.c btest.h fshow.c ishow.c driver.pl dlc Driverhdrs.pm Driverlib.pm, so not TEAM, ID or selections.c

Read Chapter 3 from Patterson and Hennessy. The chapter focusses on arithmic, but just gets two messages accross: Intel's design is inferior (based on 8087, which is partly repaired in SSE) and precision is only important for mathematicions (and chip-designers as Intel). That programmers have to be aware is only explained in the context of parallel computing (which the advice to use LPACK).

Checked the lab-assignments and only the Architecture Lab is updated (April 2015).

Looked into our recommendation for BYOD. According to Tweakers, there are 20 laptops with 5 GHz support, although I should check the 802.11 subclasses a and n. The result is 166 laptops, in the price range 300 - 450 euro.
Selecting Linux resulted in just one hit.
Found 5 laptops with Linux preinstalled on htpc beginner. The Dell is the only 13inch, three are too big (15inch), one too small (10inch).
Ubuntu gives a list of manufacturers which provide pre-installed laptops.
De Dell XPS 13 is leverbaar in NL een heeft 802.11ac.
Comparible is the ZaReason X340.
The Ubuntu shop in Belgium has Linux and Double boot systems, yet no 13inch.
ThinkPenguin has the Korora 14inch laptop for $700.
System76 has the 14inch Galago laptop for $1000.
eRacks claims to have 13inch Zenbooks, but I could only configure a 11inch. They also have a 14inch Adelie laptop. Prices start at $1295.
The 13inch Koala systems of EmporerLinux are based on the Dell Latitude. Price starting at $2100.
AvaDirect has both 13 and 14 inch laptops ($1611 and $1228 resp).

Requested an evaluation copy of the 3rd edition.
According to the authors blog, the major changes are in chapter 2-5, 7, 8, 11, 12.