Why Gnome 3 sucks for a desktop power user

When Gnome 3 replaced my familiar Gnome 2 user experience I was not very pleased. The point of this post is that instead of just complaining about Gnome 3 I would like to help make it better.

What I noticed first

My productivity suffered. I was spending more time waiting and searching for apps, information and action buttons. I'm used to be able to glance my screen and absorb a lot of information about the state of my files, apps and whatever. Trying to do this on Gnome 3 I would just waste time and get easily distracted. Why can't I even see modification times for files modified on any other day than today? Why isn't there even an option in settings for this? Why can't I change the SElinux security context of my files? I wanted to really know why the user experience sucked for me so I tried to figure out what is the difference between Gnome 2 and 3. My conclusion was that Gnome 3 is a window manager for touch based devices, but tries and fails to be a window manager for desktop as well.

Desktop UI

• Viewing distance: short
• Pointing device: mouse
• Text input: physical keyboard
• Usage: a wide selection of applications that are used with both keyboard and mouse at the same time. Ratio of interactions/time is high.
• Hardware: Fast processor and lots of memory, high resolution

Because the amount of interactions is high even the slightest delays will add up to much time spent waiting.
A desktop UI has evolved to perform most actions with minimal effort.(Minimize mouse travel, use keyboard shortcuts in order to avoid menus)

On a traditional application menu you can pretty much find all the desktop applications available for you and you can very quickly get a picture what's available in each category of applications. It is very suitable for a desktop operating system with lots of applications. On a touch based device this kind of a menu would be difficult to use as the size of items is too small to use with an inaccurate pointing device. A traditional application menu is designed to be used with a mouse.

Touch or gesture based UI

• Viewing distance: short or long
• Pointing device: touch or gesture based
• Text input: mostly on screen keyboard controlled by pointing device but also speech recognition
• Types of devices: Smartphone, tablet and television/multimedia center
• Usage: mostly limited to few applications and does not require custom commands in order to serve its purpose. Ratio of interactions/time is low.
• Hardware: Cheaper processors and less memory, resolution varies

Amount of interactions is relatively low. Delays in areas you don't frequently use(settings, tuning etc.) not that important as long as basic usage is fast.(Answering, changing channels etc.)
Basic usage is with an inaccurate pointing device and limited screen size.(Spreads content into multiple screens and displays on screen navigational cues.)

You can clearly see that Gnome 3 is designed in a way that it would be easy to use by touch. Any touch device must deal with the inaccuracy of fingers as pointing device, this reduces the maximum amount of items you can interact with at any time. Although you can use a mouse to do gestures similar to those done by fingers, it requires moving the mouse more than in a desktop user interface. Using the application menu to find an application becomes time consuming when using a mouse, especially when you have a lot of applications installed. You can expect a touch based device to contain less applications to look for. Thus the amount of applications should not be a problem on a touch device.

When gnome 3 is used on a desktop you naturally have a keyboard available as well. You can quite quickly press the super-key and type the first letters of the application name you wish to launch, provided that you don't blank out on the name of the app. For me it happens quite often. On the plus side, plugins look pretty and are quite easy to install. You can get a traditional application menu with a plugin.

A desktop window manager is fundamentally different from a touch based window manager. A desktop user interface specializes in how to best manage applications with a high on screen item density and a high resolution pointing device. Using a desktop oriented UI is difficult with an inaccurate pointing device such as the finger. Even if you had very accurate fingers it is impossible to see through your finger and thus you can only estimate within some margin of error what are the exact coordinates of the pointer. A finger also produces more random movement even when you try to keep it perfectly still and even more so when you are beginning to touch and releasing your finger from the surface of the screen. In addition to touch devices low on screen item density is suitable for a computer in the living room. It would make sense to control such a device with hand gestures or a motion tracked remote(Kinect or webcam + some OpenCV magic).

It is my belief that by currently trying to satisfy both desktop and touch device users with the same UI, you are not doing a good UI for either one. You should accept that there are fundamental differences and that the user interface should be different. Maybe the window manager should adapt the UI better depending on the input devices available? Touch based user interfaces are still relatively new and there might be some new innovations in that field. I hope that someone comes up with ways to make such interfaces easier and faster to use on a desktop computer as well.

Configuring a 4-port Sun Happy Meal card

Some time ago I rescued a pair of 4 port Oracle/SUN Happy Meal 10/100 Ethernet cards and I decided it was time to play with them. There was an issue with the sunhme driver, so I created an akmod package for Fedora 18 to patch the bug on my system so that the patch would be picked up automatically on every kernel update as well. The akmod package is available on github.

There's another quirk to these cards as well. At least on my system there is an issue with renaming the interface names that leads to one of the interfaces being renamed inconsistently(interface name ends up being something like "rename6"). I wanted to rename the interfaces nicely so that I could tell the sunhme interfaces from other interfaces in my system.

In addition to weird renames these cards have only one shared mac-address assigned to each interface, so you can't just match the interfaces by their mac-address, since they're the same.

These quirks made getting the udev rules to match rather challenging. Eventually I found a nice script that scans for the interfaces and creates a template for a proper matching udev rule.

In order to be able to use just on interface without having packets disappearing on the other interfaces, which might not be physically connected I also set unique mac-addresses for all the interfaces.

/etc/udev/rules.d/30-sun-hme.rules

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNELS=="0000:06:00.1", \
    KERNEL=="eth*", NAME="hme0", RUN+="/usr/local/bin/sunmacchanger %k 00:03:ba:a8:58:e5"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNELS=="0000:06:01.1", \
    KERNEL=="eth*", NAME="hme1", RUN+="/usr/local/bin/sunmacchanger %k 00:03:ba:a8:58:e6"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNELS=="0000:06:02.1", \
    KERNEL=="eth*", NAME="hme2", RUN+="/usr/local/bin/sunmacchanger %k 00:03:ba:a8:58:e7"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNELS=="0000:06:03.1", \
    KERNEL=="eth*", NAME="hme3", RUN+="/usr/local/bin/sunmacchanger %k 00:03:ba:a6:58:e8"

/usr/local/bin/sunmacchanger

#!/bin/bash

#make sure the interface is down, otherwise setting the mac will fail
/sbin/ifconfig $1 down
/usr/bin/macchanger --mac=$2 $1

After the changes I just needed to unload the driver, reload the rules and load the driver again and udev magic would happen

chmod +x /usr/local/bin/sunmacchanger
rmmod sunhme
udevadm control --reload-rules
#loading my patched version of sunhme driver
modprobe sunhme2g

Now I have 4 100M interfaces on one card. It'll come handy when routing traffic outside my LAN and I could have redundancy in case one WAN connection goes down.

Unless I spesifically tell NetworkManager not to bring up interfaces hme1-hme3, NetworkManager will bring those interfaces up. This causes some log spam:

output of dmesg

[ 6438.361078] hme1: Auto-Negotiation unsuccessful, trying force link mode
[ 6438.369059] hme2: Auto-Negotiation unsuccessful, trying force link mode
[ 6438.373052] hme3: Auto-Negotiation unsuccessful, trying force link mode
[ 6447.974274] hme1: Link down, cable problem?
[ 6447.982269] hme2: Link down, cable problem?
[ 6447.986242] hme3: Link down, cable problem?
[ 6459.990561] hme1: Auto-Negotiation unsuccessful, trying force link mode
[ 6459.998551] hme2: Auto-Negotiation unsuccessful, trying force link mode
[ 6460.002549] hme3: Auto-Negotiation unsuccessful, trying force link mode
[ 6469.603795] hme1: Link down, cable problem?
[ 6469.611764] hme2: Link down, cable problem?
[ 6469.615756] hme3: Link down, cable problem?

You can prevent NetworkManager from needlessly bringing up these interfaces by adding the macs to the unmanaged-devices parameter in [keyfile] section and checking that keyfile plugin is loaded in [main] section's plugins parameter.

/etc/NetworkManager/NetworkManager.conf

[main]
plugins=ifcfg-rh,keyfile

[keyfile]
unmanaged-devices=mac:00:03:ba:a8:58:e6;mac:00:03:ba:a8:58:e7;mac:00:03:ba:a8:58:e8

It's not exactly plug and play, but playing with these cards is a good learning opportunity. It wouldn't hurt to have some kind of graphical configuration tools for doing some of this stuff. It requires some knowledge about udev and NetworkManager + a search engine to do this "manually".

Google Redirect Rewrite memory usage

Image courtesy of Open Clip Art Library

I previously found out that you can pretty easily rewrite url's for Squid. Today I noticed Squid launches a bunch of child processes to do the url rewriting. I got curious about the memory usage. I had a feeling that the Perl version would not consume as much memory as PHP and it appears it is indeed so.

I tested both PHP and Perl versions to see how much memory they would consume. First I checked the memory usage of the PHP version after browsing a bit. Then I changed squid.conf to use the Perl version and again checked the memory usage. Squid had just launched one googlerewriter child process, so I browsed some more and then checked again. I'm guessing Squid starts the processes when it actually needs them.(ps. Documentation confirmes this) Anyway some processes then appeared to have been launched.

Fields

MAJFL

Major page fault: The number of major page faults that have occurred with this process

TRS (kB)

Text resident set: The amount of physical memory devoted to executable code

DRS (kB)

Data resident set: The amount of physical memory devoted to other than executable code

RSS (kB)

Resident set size: The portion of a process's memory that is held in RAM. The rest of the memory exists in swap or the filesystem (never loaded or previously unloaded parts of the executable).

Even for a tiny script php version caused some page faults and it's using way too much memory for the task it's doing.

PHP

$ ps faxv
  PID TTY      STAT   TIME  MAJFL   TRS   DRS   RSS %MEM COMMAND
13098 ?        Ss     0:00      0  5047 12668  2608  0.0 /usr/sbin/squid -a 3128 -f /etc/squid/squid.conf
13100 ?        S      0:01      5  5047 35240 25052  0.4  \_ (squid-1) -a 3128 -f /etc/squid/squid.conf
13101 ?        S      0:00      0     5  3942   992  0.0      \_ (logfile-daemon) /var/log/squid/access.log
13102 ?        S      0:00      1     2  3793   740  0.0      \_ (unlinkd)
13109 ?        S      0:00     50  3385 43962  7812  0.1      \_ /usr/bin/php /usr/local/bin/googlerewriter.php
13111 ?        S      0:00      0  3385 43962  7816  0.1      \_ /usr/bin/php /usr/local/bin/googlerewriter.php
13115 ?        S      0:00      0  3385 43962  7816  0.1      \_ /usr/bin/php /usr/local/bin/googlerewriter.php
13116 ?        S      0:00      0  3385 43962  7812  0.1      \_ /usr/bin/php /usr/local/bin/googlerewriter.php
13117 ?        S      0:00      0  3385 43962  7816  0.1      \_ /usr/bin/php /usr/local/bin/googlerewriter.php

$ top
  PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
15552 squid     20   0 47348 7812 5428 S   0.0  0.1   0:00.05 googlerewriter.
15735 squid     20   0 47348 7816 5428 S   0.0  0.1   0:00.03 googlerewriter.
15736 squid     20   0 47348 7816 5428 S   0.0  0.1   0:00.03 googlerewriter.
15741 squid     20   0 47348 7816 5428 S   0.0  0.1   0:00.03 googlerewriter.

The resident set size of the Perl version is 31% that of the PHP version, or in other words the PHP version is using 3 times as much memory per process. By using the Perl version you'd save at least 5.2MiB. Not that this matters much on my current proxy server, but for an embedded server it would matter.

Perl

$ ps faxv
  PID TTY      STAT   TIME  MAJFL   TRS   DRS   RSS %MEM COMMAND
13382 ?        Ss     0:00      0  5047 12668  2608  0.0 /usr/sbin/squid -a 3128 -f /etc/squid/squid.conf
13384 ?        S      0:01      0  5047 37988 25308  0.4  \_ (squid-1) -a 3128 -f /etc/squid/squid.conf
13387 ?        S      0:00      0     5  3942   992  0.0      \_ (logfile-daemon) /var/log/squid/access.log
13388 ?        S      0:00      0     2  3793   740  0.0      \_ (unlinkd)
13396 ?        S      0:00      0     3  8700  2460  0.0      \_ /usr/bin/perl /usr/local/bin/googlerewriter.pl
13426 ?        S      0:00      0     3  8700  2376  0.0      \_ /usr/bin/perl /usr/local/bin/googlerewriter.pl
13427 ?        S      0:00      0     3  8700  2372  0.0      \_ /usr/bin/perl /usr/local/bin/googlerewriter.pl
13429 ?        S      0:00      0     3  8700  2460  0.0      \_ /usr/bin/perl /usr/local/bin/googlerewriter.pl
13430 ?        S      0:00      0     3  8700  2460  0.0      \_ /usr/bin/perl /usr/local/bin/googlerewriter.pl
13431 ?        S      0:00      0     3  8700  2460  0.0      \_ /usr/bin/perl /usr/local/bin/googlerewriter.pl

$ top
  PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
13396 squid     20   0  8704 2460 1724 S   0.0  0.0   0:00.19 googlerewriter.
13429 squid     20   0  8704 2460 1724 S   0.0  0.0   0:00.03 googlerewriter.
13430 squid     20   0  8704 2460 1724 S   0.0  0.0   0:00.02 googlerewriter.
13431 squid     20   0  8704 2460 1724 S   0.0  0.0   0:00.02 googlerewriter.
13426 squid     20   0  8704 2376 1716 S   0.0  0.0   0:00.04 googlerewriter.
13427 squid     20   0  8704 2372 1716 S   0.0  0.0   0:00.03 googlerewriter.

Faster browsing aka Google Redirect Rewrite

Image courtesy of Open Clip Art Library

Once again I got annoyed by having to wait for Google to redirect me. I also think it's none of Google's business to know which sites I do visit especially if they can't be quick about it. So I decided to get rid of the delay.
I checked if there's a plugin for that and it seems there is. You can install Remove Google Redirects from Chrome Web Store. Being a paranoid weirdo like I am that still wasn't enough. I already had a Squid proxy that I had configured to make it so that you couldn't even know that some websites were blocked by my ISP(Sonera). It made sense to try and figure out if there was a trick that I could do with squid that allows me to get rid of the middle man(Google) in the redirect process.

And behold for the creators of Squid have indeed been so wise as to add a way to mangle the urls. All I had to do was to write a script that takes the url, checks if it's a google redirect url and if so, parses the url to get the actual url where we want to go and return that. The example on Squid feature page was a good place to start and this is what I came up with:

Perl Version

#!/usr/bin/perl

use URI;
use URI::QueryParam;

$|=1;
while (<>) {
    chomp;
    @X = split;
    $url = $X[1];
    #check if this is a google redirect url
    if ($url =~ /\/\/.*\.google\.[^\/]+\/url/) {
        my $uri = URI->new($url);
        $url = $uri->query_param("url");
        print $X[0]." 302:$url\n";
    } else {
        print $X[0]." \n";
    }
}

I had to install a couple of Perl modules while I was trying to refamiliarize myself with Perl so I wanted make a PHP version of the same helper. With PHP I wouldn't have to install any extra modules when some day I decide to use this on some other machine. I usually have PHP installed everywhere.

PHP Version

#!/usr/bin/php
<?php

function convertUrlQuery($query) {
    $queryParts = explode('&', $query);

    $params = array();
    foreach ($queryParts as $param) {
        $item = explode('=', $param);
        $params[$item[0]] = $item[1];
    }

    return $params;
}
while(1){
    $line = trim(fgets(STDIN)); // reads one line from STDIN
    $params = explode(" ", $line);
    $pattern = '/\/\/.*\.google\.[^\/]+\/url/';

    if (preg_match($pattern, $params[1], $matches, PREG_OFFSET_CAPTURE, 3)) {
        $parts = parse_url($params[1]);
        $query = convertUrlQuery($parts['query']);
        $url = urldecode($query['url']);
        echo $params[0]." 302:$url\n";
    } else {
        echo $params[0]." \n";
    }
}

In the end I like that with Perl I didn't have to write any functions for simple things like url parsing, but unless I package this as an installable package I could not just drop it in and expect it to work since I had to install the extra stuff as modules.(Yes I could have written my own implementation, but I'm not that much into reinventing the wheel. Also I was a bit impatient to get the script ready so I could see the results) With the PHP version I could just drop it in and as long as I had PHP installed it would work.

I strongly recommend adding a line in squid.conf It really makes a difference.

url_rewrite_program /path/to/googleredirectrewriter

Setting up Prestashop file permissions on Fedora

Sometimes I need to write important things somewhere I can find them. That's the case again with setting up Prestashop file permissions on a SElinux enabled system such as Fedora.

cd prestashop
chown -R apache:sebastian
# allow user and group search directories and set the new files inherit the group of parent folder 
find . -type d -exec chmod ug+xs {} \;
# don't allow others to do anything and allow my group to read and write all, don't allow apache to write anything
chmod -R u-w,o-rwxs,g+rw .
# set permissions of newly created files so that others cannot do anything them
umask o-rwx
# set selinux context so that apache can access everything
chcon -t httpd_sys_content_t -R .
# set selinux context and permissions so that apache can write into places it needs to be able to write
chcon -t httpd_sys_rw_content_t -R config cache log img mails modules translations upload download sitemap.xml
chmod -R u+rw config cache log img mails modules translations upload download sitemap.xml

This page was not left blank after all

Like a break after a paragraph, a blank page is something you would expect after a chapter, after the table of contents and before appendices. Blank pages make it easier to read the content for which it acts as a separator.

For some reason a practice of adding disclaimers to the blank pages has been gaining popularity. Some are even promoting it. What is the reason for this? Are people getting too stupid to figure out on their own that a blank page is there just to separate content? It is possible that I'm just suffering from Baader-Meinhof Phenomenon again, but I'm sure that books used to contain a lot of blank pages without needing disclaimers on them.

I like to immerse myself when I'm reading and just consume the words as quickly as I am able to. Sometimes I find myself reading a line that has no relevance to the work I'm reading. There are a few variations, but it usually reads something like:

This page intentionally left blank

It's a lie. Actually it's not even a sentence(lack of a verb). The page ceases to be blank after it is written on. I'ts distracting. I's like a speaker keeping on talking without interruption instead of taking a pause to emphasize some point or to give some time for thinking. It's kind of like replacing every possible pause with verbal fillers. It's unnecessary and confusing. 

Okay, there might be situations where the author has not made it clear that the previous segment has ended, but then it's the matter of the author not doing a good enough job or you're reading something like poetry. A disclaimer at this point won't help you very much in any case. Sometimes it's distracting enough for someone to stop reading and instead write a blog article about it. So do everyone a favor and don't put empty page disclaimers, maybe then someone else is spared from an article like this.

What's wrong with a simple page number?

An open letter - Re: Welcome to the Aalto Talk with Linus Torvalds!

Hi.

Since this is a topic I have thought about writing on my blog and discuss with people, this shall be an open letter with a copy on my blog, Semantics(http://semantiikkaa.blogspot.fi/).

I feel that traditional valedictions(http://en.wikipedia.org/wiki/Valediction) are boring, don't accurately represent my attitude and don't deliver what I want to say. To be honest, they are quite archaic and mostly submissive to the point that it's ridiculous and when taken literally even false. Even an insincere person can type the word "sincerely". Honesty is important to me as is accurate self expression, thus "May the Force be with you" is a farewell that is most suited for me, not only because I'm a huge science fiction fan. I will never be anyone's humble servant, but I do wish a methaphorical Force be present in everyone's life. That something which drives us (to do better).

http://en.wikipedia.org/wiki/May_the_Force_be_with_you


ps. Sometimes I end my letters with:

Live long and prosper,
Sebastian Mäki

12.06.2012 21:53, Zaira Mammadova kirjoitti:

Hi Sebastian, 

Thank you! 

Out of curiosity, what does "may the Force be with you"? :)

-Zaira