Mononono? What?

Mononono is a package I just heard and the purpose of it is to conflict with any other packages which needs Mono.

There are quite a few on Linux world, and you probably have one or two apps on your computer and you are not even knowing about. Many people do not like Mono since the fundamental design is from Microsoft's .NET framework. I do not like it, either. Because I have to have another set of libraries in my system.

So this genius, Tim Chase, created a package to solely conflict those packages depend on Mono. This is the most brilliant idea I have ever seen.

Let's do this together: Mono, (pause for a second) NO! NO! (Point your index figure up, then wave it and shake your head a bit)

PS. On Gentoo, use package.mask to do the same thing.

(via Arch Forum post)

Geeqie Image Viewer

A commenter mentioned a image viewer I hadn't heard before, Geeqie. It was forked from gqview. It is not in Gentoo packages, but it is easy to compile. The version I used is 1.0beta2.

It is really fast and most important feature is Raw image support. With feh, I have to use UFRaw to convert raw images into jpeg format. But it's okay for me because I don't view raw image often, well, I don't view other images often, either. The only problem with Geeqie is it has too many features ( :-) ) I do not use, especially those editing functions.

Here is a screenshot of it:

You can see another good feature in the filelist of the screenshot, it merges images with same main filename and different image file types. It's a nice feature, I think.

The other thing I noticed when I was configuring it, a word showed up, “Win32.” I don't know if it is really supporting Windows, I didn't dig in.

Anyway, I will keep Geeqie on my system just for the raw images. Feh is still easier to use since I am usually in $ prompt or MC, I only need to run feh . or use F2 menu to bring up feh.

OpenSUSE 11.2

This is my second time of installing OpenSUSE but I had forgot what it was like for the first time. I downloaded the DVD spin, the installation only took 22 minutes for my computer. KDE was selected by default, I didn't change to GNOME.

Before I put the disc to the computer, I had thought about “I should try to avoid using terminal this time!” Well, that hope didn't last long after the installation finished.

Once the first-time boot, the first thing I had to do was to enable the network, the DSL. It was not hard to use YaST (Administrator Settings) to configure DSL connection, but it needed a required package, smpppd. That was easy again if you know the commandline or you didn't get locked up from that awesome PackageKit. (Which is also as good as NetworkManager, these two have earned my sincere respect, to keep away from them)

I mounted the DVD to /media and use rpm to install /media/suse/i586/smpppd-*.rpm. I added a new DSL connection, it worked very well. In some distros, I had to remove a default gateway from routing table after just brought up the connection without rebooting.

Next thing is to fix the screen resolution, it is relative simple. I added a new software repository from nVidia and searched for driver again, installed it. Then stuck on a smaller resolution 640×480. Switched back to runlevel 3, ran nvidia-xconfig and set the ModeLine (I need this, or I would have Out of Range, I believed this is the driver's fault). The desktop effects works well after the driver installed, I couldn't say it runs fast but smooth enough.

Adobe Flash already in place (or after updated, I couldn't be sure), the non-free media codecs are not problem either, you only need to add additional software repository. KDE's Kaffeine uses Xine, thus libxine1-codecs from Packman repository is the right one. However, it would have dependency conflicts, the resolution on OpenSUSE's YaST is the one thing I have to mention, check the screenshot below:

It provides intelligent options to let you resolve the conflict, in my case, the first one can resolve perfectly. OpenSUSE uses RPM, too, as same as Fedora does. I haven't seen similar thing on Fedora. If I were using Fedora, I have to manually uninstall those conflicts. But think later, the packaging policy in Fedora might be better, it would actually result a several upgrades when you add new repository, therefore conflicts would not be the case usually.

OpenSUSE is nice distribution, I haven't had big problem with it (though I have to use terminal). Too bad, I only have few days to try it out, Fedora 12 is available, I am going to try it next.

Cannot wait for Fedora 12?

Are you expecting Fedora 12?

while [ 1 ]; do wget -q http://fedoraproject.org/en/get-fedora -O - | grep -q "f12" - && notify-send -u critical 'Hooray! Fedora 12 is available!' && break ; sleep 10m ; done

Get notified!

Migrating to tmux from GNU/Screen

If you have heard of or have used GNU/Screen, then you know what tmux is for; if you haven't, you probably do not want to read the following content, or you have wasted lots of time in doing terminal window cycling.

What's the major difference between these two? The splitting:

The numbers in blue indicate the pane number

(Default key: Ctrl+b q)

That maybe over-splitting. Anyway, it's the main reason that I decided to switch to tmux. I know somewhere on the internet has patch for Screen. But I didn't manually compile program, it would be not easy for me to maintain. If you have a good alternative, why bother to keep to the one lacking the functionality which you need. And Screen is no longer to add new feature, it's in bugfix-only. tmux is new, highly active.

tmux's current version is 1.1. I had encounter a problem with version 1.0 when with 256 colors. Some color escape code doesn't do what it suppose to do.

It only took me an hour to create my own configuration to get similar key bindings and status bar.

The one on top is tmux. They are nearly identical and tmux is actually better.

The memory footprint is much smaller than Screen if you usually use several sessions. On my Gentoo amd64, when you start a tmux server, it takes 2.35 MB without counting Bash's; Screen takes 2.6 MB. If you fire up a second session, tmux use 1.0 MB more but Screen uses another 2.6 MB.

My configuraion ~/.tmux.conf

# Last modified: 2009-11-12T05:59:41+0800

# Change prefix key to Ctrl+a
unbind C-b
set -g prefix C-a

# Last active window
unbind l
bind C-a last-window

# Copy mode
unbind [
bind Escape copy-mode
# Use Vi mode
setw -g mode-keys vi
# Make mouse useful in copy mode
setw -g mode-mouse on

# More straight forward key bindings for splitting
unbind %
bind | split-window -h
bind h split-window -h
unbind '"'
bind - split-window -v
bind v split-window -v

# History
set -g history-limit 1000

# Pane
unbind o
bind C-s down-pane

# Terminal emulator window title
set -g set-titles on
set -g set-titles-string '#S:#I.#P #W'

# Status Bar
set -g status-bg black
set -g status-fg white
set -g status-interval 1
set -g status-left '#[fg=green]#H#[default]'
set -g status-right '#[fg=yellow]#(cut -d " " -f 1-4 /proc/loadavg)#[default] #[fg=cyan,bold]%Y-%m-%d %H:%M:%S#[default]'

# Notifying if other windows has activities
setw -g monitor-activity on
set -g visual-activity on

# Highlighting the active window in status bar
setw -g window-status-current-bg red

# Clock
setw -g clock-mode-colour green
setw -g clock-mode-style 24

There is really no much need to explain. The first thing I did was to change the prefix key  to C-a, C-b is really hard to press.

The other thing I like is you can specify the terminal window's title with the format you like.

Panes — Splitting, cycling, etc

Basically, you only need to know four keys for controlling:

Key Default Action
h,|    %    Split window horizontally
v,-    "    Split window vertically
C-s    o    Go to next pane
x      x    Kill the active pane
q      q    Show pane numbers
A-Arrow Key Resize the active pane
C-Arrow Key Resize the active pane by one line or on character 

I think h, v are more straight forward in thinking then %, ", and |, - are more clear but it's harder to press because you have to use Shift key for |.

C-s is better than o, it would be even better if you use C-a as prefix key. You can press in this sequence: C-a (still hold Ctrl) s. A key is next to S, it's much easier to go next pane.

One thing I am not satisfied with panes is it's not easy to know which pane is active if you do not pay attention and the programs do not have blinking cursor. I have the terminal title to indicate the active pane number, so I am able to tell which pane I am in.

Scripting

Sometimes you will want to have presetting windows to be prepared automatically. For example, you may want to have foo program in window 0, window 1 has two split panes, and have bar program in pane 1. Because tmux is highly script-able.

I was actually hoping to use alternative configuration using -f argument when fire up tmux, but I didn't get it well after some time point. I don't why it didn't seem to work.

Anyway, if you create a script, there is no problem at all.

Here is an example of how I bring up centerim:

#!/bin/sh
tmux new-session -d -s centerim centerim
tmux new-window -t centerim:1 CIM_status_setter.py
tmux select-window -t centerim:0
tmux -2 attach-session -t centerim

The first command creates a detached (-d) new session named (-s) centerim and also run centerim in the first window of this new session. It then creates a new window and assigns (-t) to session centerim's window 1, and also run a Python script. The third one selects the window 0 as the active window.

The last one attaches to session centerim, from here, we would be using this session centerim. The -2 forces tmux to use 256 colors.

Note that if you need to run a program with arguments, you will need to use quotes, for example:

tmux new-session -d -s session_name 'program arg1 arg2'

Vim

After I switched to tmux, I found out the mouse support in Vim didn't work. My original setting for mouse is:

set mouse=a
set ttymouse=xterm2

Now I have to use:

set mouse=a
set ttymouse=xterm

I still can move the cursor using mouse but the visual selection is different than when ttymouse=xterm2.

xterm2       Works like "xterm", but with the xterm reporting the
             mouse position while the mouse is dragged.  This works
             much faster and more precise.

Hardcopy and Logging

Currently I don't see tmux has both. In Screen, you can use them by press C-a h and C-a H, respectively.

A related operation is to use copy mode, manually select the area, copy to buffer, then use save-buffer command to save to file.

Clock

You can show the current time in active pane, default key is t.

The only customization of this clock mode is the color, not really useful feature for me.

Other keys

I think the following keys are most useful for me:

Key    Default Action
C-a       l    Last active window
Escape    [    Enter copy-mode
PageUp  PageUp Same as above
:         :    Enter command
?         ?    Show keybindings
s         s    Choose session to attach
d         d    Detach from current session

Conclusion

tmux is easy to learn, you only need the manual of it. The man page is written clear and very useful. Only few things that I could not have tmux to do for me as I had in Screen. I have been using tmux for days, I really don't have a big problem with it. I may uninstall Screen very soon.

My mother now uses Arch Linux... and...

Another interesting thread got me, I subscribed to the updates when it was just posted. I was wondering how they got someone to use Linux, especially the older. I had tried but I had no victims so far. ;p

The discussion went normally until post #17. In case the post or thread got removed. I saved a screenshot.



Wtf? (Updated: that post got moderated)

This thread is getting more interesting... The OP replied something:

“... I know that when I get older and get married, I'm going to be running a Linux house. It may seem horrible of me, but I couldn't marry a Windows user. I'd compromise with OS X, probably, if that's what my wife really prefers. It's that important to me...”

Serious?

BFS (Brain Fuck Scheduler) Test

A post caught my interesting, which is about the huge boost on x264 encoding. We will all see the change when the kernel 2.6.32 comes, it uses BFS, a new process scheduler. The current kernel uses CFS (Completely Fair Scheduler). Phoronix has a benchmark report for BFS.

I decided to do a little test. Because I have no background, so the test is just a rough numbers. Here is my system:

• Core 2 Duo T5600 1.83GHz
  
• Gentoo amd64
  
• Kernel 2.6.31-gentoo-r4 (It's kernel 2.6.31 with genpatch)
• Kernel 2.6.32-rc5 (Just for reference)
  
• kernel config file from my 2.6.30 configuration
• BFS v304
  

Simple concurrent process test

First, I have no idea how should I test. I just want to get some number to read. My test program is written in Python (So you knew I really have no idea), because Python's threading could only use one core, therefore I used processing to utilize my two cores. The test code shows as follows:

#!/usr/bin/env python

from time import sleep
from time import time
import os

from processing import activeChildren
from processing import Process


MAX_COUNT = 1000000
MAX_PROCESS = 32
PASSES = 5


def counter():
  
  c = 0
  while c < MAX_COUNT:
    c += 1


def do_test(PROCESS_COUNT):

  processes = []
  for i in range(PROCESS_COUNT):
    p = Process(target=counter)
    p.setDaemon(True)
    processes.append(p)

  t_start = time()
  for p in processes:
    p.start()
  while activeChildren():
    sleep(0.001)
  t_end = time()
  return t_end - t_start


def main():

  avg_times = []
  for concurr in range(1, MAX_PROCESS + 1):
    print 'Running concurrent %3d processes...' % concurr,
    acc_time = 0.0    
    for i in range(PASSES):
      acc_time += do_test(concurr)
    avg_time = acc_time / PASSES
    avg_times.append(avg_time)
    print '%9f seconds' % avg_time

  fname = 'test-c%d-p%d-%s' % (MAX_COUNT, MAX_PROCESS, os.uname()[2])
  f = open(fname, 'w')
  data = (os.uname()[2], avg_times)
  f.write(repr(data))
  f.close()
  print
  print 'Data written to %s.' % fname


if __name__ == '__main__':
  main()

As you can see, the created process doesn't do actual things. It just keeps counting up. Each test would run five times and get an average of elapsed time.

#Proc  2.6.31   (Cost)  2.6.31-bfs   (Cost)  2.6.32-rc5   (Cost)     Impr%
  1  0.156739( 0.156739)  0.151051( 0.151051)  0.156921( 0.156921)   3.63%
  2  0.220114( 0.110057)  0.152029( 0.076014)  0.155770( 0.077885)  30.93%
  3  0.311475( 0.103825)  0.230545( 0.076848)  0.238812( 0.079604)  25.98%
  4  0.318061( 0.079515)  0.316369( 0.079092)  0.307760( 0.076940)   0.53%
  5  0.451945( 0.090389)  0.379189( 0.075838)  0.390504( 0.078101)  16.10%
  6  0.493751( 0.082292)  0.462939( 0.077157)  0.466906( 0.077818)   6.24%
  7  0.617738( 0.088248)  0.534748( 0.076393)  0.542779( 0.077540)  13.43%
  8  0.639118( 0.079890)  0.614359( 0.076795)  0.619499( 0.077437)   3.87%
  9  0.759511( 0.084390)  0.685477( 0.076164)  0.698372( 0.077597)   9.75%
 10  0.782722( 0.078272)  0.766383( 0.076638)  0.775433( 0.077543)   2.09%
 11  0.883538( 0.080322)  0.834171( 0.075834)  0.852352( 0.077487)   5.59%
 12  0.942532( 0.078544)  0.913356( 0.076113)  0.930670( 0.077556)   3.10%
 13  1.056529( 0.081271)  0.998580( 0.076814)  1.014098( 0.078008)   5.48%
 14  1.096089( 0.078292)  1.062566( 0.075898)  1.092146( 0.078010)   3.06%
 15  1.207977( 0.080532)  1.136702( 0.075780)  1.172611( 0.078174)   5.90%
 16  1.276357( 0.079772)  1.215091( 0.075943)  1.253329( 0.078333)   4.80%
 17  1.360708( 0.080042)  1.289036( 0.075826)  1.323230( 0.077837)   5.27%
 18  1.415339( 0.078630)  1.372739( 0.076263)  1.408926( 0.078274)   3.01%
 19  1.507686( 0.079352)  1.442193( 0.075905)  1.486329( 0.078228)   4.34%
 20  1.617503( 0.080875)  1.510492( 0.075525)  1.562270( 0.078114)   6.62%
 21  1.652496( 0.078690)  1.592773( 0.075846)  1.644975( 0.078332)   3.61%
 22  1.737832( 0.078992)  1.680954( 0.076407)  1.735154( 0.078871)   3.27%
 23  1.797144( 0.078137)  1.738987( 0.075608)  1.833433( 0.079714)   3.24%
 24  1.873404( 0.078058)  1.814224( 0.075593)  1.880322( 0.078347)   3.16%
 25  1.959188( 0.078368)  1.886172( 0.075447)  1.958433( 0.078337)   3.73%
 26  2.044073( 0.078618)  1.967344( 0.075667)  2.041252( 0.078510)   3.75%
 27  2.094033( 0.077557)  2.032489( 0.075277)  2.110076( 0.078151)   2.94%
 28  2.186407( 0.078086)  2.112829( 0.075458)  2.197447( 0.078480)   3.37%
 29  2.256274( 0.077803)  2.187584( 0.075434)  2.267832( 0.078201)   3.04%
 30  2.341825( 0.078061)  2.263803( 0.075460)  2.344355( 0.078145)   3.33%
 31  2.413136( 0.077843)  2.338420( 0.075433)  2.446170( 0.078909)   3.10%
 32  2.500092( 0.078128)  2.429601( 0.075925)  2.522627( 0.078832)   2.82%

Note that Improvement% is 2.6.31-bfs improvement over 2.6.31, cost means the time to run 1000000 count per process,

Compilation Test

For a real use test, I think compilation is a good one to do. So I chose e2fsprog 1.41.9 to test, here are the result:

#Job 2.6.31  2.6.31-bfs 2.6.32-rc5  Impr%
  1 36.232000 35.235000 35.746000   2.75%
  2 23.511000 20.168000 20.327000  14.22%
  3 21.740000 20.885000 20.902000   3.93%
  4 21.700000 21.308000 21.397000   1.81%
  5 21.954000 21.433000 21.741000   2.37%

Note that Improvement% is 2.6.31-bfs improvement over 2.6.31.

Conclusion

In both tests, all got improved. With the number of concurrent running processes and the number of jobs are the same as the number of cores, the improvements have reached peaks.

One thing more interesting is, with CFS, the performance is better when you use 3 to 4 jobs, especially 4 jobs, it has best time. And the cost comes to minimum.

With BFS, the cost time reaches minimum just 2 jobs. It begins slightly reducing improvement after 2 jobs, the number of cores.

Also BFS has resulted smaller kernel build:

Size    Kernel
1991232 kernel-x86_64-2.6.31-gentoo-r4
1974720 kernel-x86_64-2.6.31-gentoo-r4-bfs

It seems that CFS reaches the best performance at 2*N processes and BFS reaches the best performance at N processes, where N is the number of cores. And BFS always got the better performance in these tests.

CFS doesn't stay steady after 2*N processes, the curve finally becomes steady after 24 processes. But BFS is already steady at N processes.

BFS does look good.

(results ploting python codes: 1, 2, 3)