Pedaling Upwards

From my previous article Disable pulseaudio in Ubuntu 9.04 I mentioned a weird experience of random hangs (or more precisely, lockups!) when I am using Ubuntu 9.04. This notice is from my office’s Dell’s PC with Intel Quad-core. Nothing special. But it happens randomly. Some lockup includes mouses and keyboard for as long as 1 to 3 minutes, but some lockups are except for mouse and keyboard. I do a lot of googles but to no avail. Seems like I was using the wrong keywords. I came cross this bug report, which was really giving me an insight into this problem, and its possible solution. (even though this bug report was already marked as “invalid”)

So this definitely is not a pulseaudio problem, nor a video driver problem. It may be a kernel problem. The freezes or lockups happened on my two PCs with different sets of hardwares but with same Ubuntu version. It was more like a kernel problem. So I will see if it will disappear after I compiled my own kernel or using a newer version kernel. Well, this is really the weirdest thing I ever had since Ubuntu 5.10. But at this time I have no time to varify the possible solutions described in this bug report (because the lockup is definitely a really annoying experience.. )

先說一下，這篇炫燿的成份比較多...XD

公司的電腦配的是兩顆實體Intel Xeon的Dell workstation T5400，打開/proc/cpuinfo嚇了一跳，還需要用 | less才看的完(因為會跳頁)，原來是每個Xeon都是Quad Core，所以這台總共有8個CPU.... 這個感覺有點像是，去非洲當研發替代役的朋友的朋友說過的一種fu：非洲直接跳過有線網路的時代，從沒有網路直接跳無線網路，這樣的感覺。我自己使用的電腦還沒有進入multi-core CPU的階段，現在來公司，直跳Quad core x 2.. 電腦用起來只有：哇塞，原來這才是現代的電腦阿... 不管開什麼軟體做什麼事情，總是沒看過CPU跑到一半以上~

於是經由keiko的建議，以及看到他的這篇[Qt 4.5.2]，我利用中午休息的時間來compile一下Qt 4.5.2 opensource edition:

time make -j 8
...
real	17m55.374s
user	97m10.652s
sys	7m46.397s

This is done on this computer:

這該怎麼說呢？18分鐘內compile完，我的NB要跑幾個小時..XD

According to [Ubuntu 9.04 Jaunty – Keeping the beast Pulseaudio at bay] by idyllictux, you can disable (not remove) pulseaudio in Ubuntu 9.04, so that you can use ALSA or OSS for some sakes. As for my sake, my two PCs around got problems using pulseaudio. One was that when I played music via Cmus, there were some sudden audio hangs and system hangs every now and then. It bothered a lot because sometimes it also blocked the usages of all input/output devices! (keyboard, mouse, and often X itself) But I cannot be sure if it resulted from pulseaudio. The other was that I got pure noises playing audio/video in my Ubuntu since a reboot after a kernel upgrade. It happened since last Friday, which also (I cannot be sure, either) caused my PC to hang during the weekends, and I lost two stages’ records of Tour de France 2009 on channel FMTV. It was a miserable thing to me.

Well, after I disabled pulseaudio on my two sets of Ubuntu 9.04 today, I found the above problems gone, at least for longer than 3 hours. I hope this solved the problem, and probably yours too, by trying to fall back on ALSA.

Running commands in the background (e.g. via SSH) without being stopped when logged out
http://www.cyberciti.biz/tips/nohup-execute-commands-after-you-exit-from-a-shell-prompt.html

Basically there are 3 obvious ways to achieve this:

1. nohup ./cmd &
2. echo “abs_path_to_cmd/cmd” | at now + 1 minute

3. ./cmd &; disown -h

A couple of days ago E.Sun Bank released a Firefox Add-on for Linux, which makes it possible for Linuxers like me to use WebATM under Linux. Indeed a great news! With my CASTLES EZ100PU card reader, I can now display my account balance, do transferring, etc. under my Linux PC.

Things keep on coming up to make Linux a complete substitute for Windows now. I should keep a note for those who care about this:
(Note: this may only work on Ubuntu 9.04 or 8.10, since mine is U9.04.)

1. Download necessary tools  (do not install pcscd, you should build it manually to make it support libusb instead of the default libhal)
   sudo apt-get install libccid libpcsclite1 libpcsc-perl pcsc-tools
2. Build your own pcscd (PC/SC Smart Card Daemon)
   wget https://alioth.debian.org/frs/download.php/3017/pcsc-lite-1.5.3.tar.bz2
   ./configure --enable-usbdropdir=/usr/lib/pcsc/drivers --disable-libhal && make
   make check; sudo make install
3. Get driver and install as it suggests
   http://www.casauto.com.tw/in-download-02.aspx?wcid=C_00000017&id=P_00000009&cid=C_00000001
4. put /usr/local/sbin/pcscd to your rc.local script... or run it now
5. run pcsc_scan, if success, it will display something like
   Mon Jun 22 22:01:10 2009
    Reader 0: CASTLES EZ100PU 00 00
     Card state: Card removed
6. Go up on https://netbank.esunbank.com.tw/webatm/default.aspx and use WebATM on Linux for the first time!

Those steps come on #50 reply on this page. If you prefer reading Chinese, go ahead instead.