Yet Another Blog

April 22, 2015

Keyboard bug in Intellij under Ubuntu

Filed under: computer, Java, linux — Tags: , , , , , , — guilleml @ 3:09 pm

If you’re using intellij under Ubuntu you probably noticed the keyboard stops working sometimes just in the IDE.
This is very anoying and there is an open issue:
If you want to enable again the keyboard execute this command on any terminal:

ibus-daemon -rd

This seems to work in versions 14.04 and 14.10.


September 9, 2008

Increase battery life in your linux laptop

Filed under: computer, hacks, linux, Software — Tags: , , , , , , , , , — guilleml @ 7:10 pm

Recently I’ve bought a laptop, Dell Inspiron 1525 with a T5750@2Ghz and a 9 cell battery.

I installed KDE4, plasma, desktop effects…it’s cool, really cool,  but then I discovered powertop, a tool that is able to recommend some settings to make  your CPU to awake less times every second. The tools shows yo a list of the tasks that are awaking the CPU so you can try to get a more power-efficent system.

It recomends you some actions to take, you just accept or not them, as set the SATA bus in low-power mode, USB autosuspend, set ondemand cpu freq governor, delay writing to the hard disc, etc…

I noted KDE4 is cool but not when you’re using the battery so I installed fluxbox and XFCE, both are nice, XFCE seems to wake up less the CPU, then I started to look for scripts and patchs to waste less energy.

So here are the tuning I’ve done to my laptop:



# Go fast on AC power.  Similar to default Ubuntu settings
if on_ac_power; then
# Set the drive to mostly stay awake
hdparm -B254 -M 254 /dev/sda

# Remount ext3 filesystems so the journal commit only happens every 60
# seconds.  By default this is 5 but, I prefer to reduce the disk
# activity a bit.
mount -o remount,commit=60 /
mount -o remount,commit=60 /media/sda3

# Turn off the laptop mode disk optimization
echo 0 > /proc/sys/vm/laptop_mode

# Manually set the wifi driver to no power savings.
#echo 6 > /sys/bus/pci/drivers/iwl????/0000\:??\:00.0/power_level

# Set kernel dirty page value back to default
echo 10 > /proc/sys/vm/dirty_ratio
echo 5 > /proc/sys/vm/dirty_background_ratio

# Only wakeup every 60 seconds to see if we need to write dirty pages
# By default this is every 5 seconds but, I prefer 60 to reduce disk
# activity.
echo 6000 > /proc/sys/vm/dirty_writeback_centisecs

# Turn off sound card power savings
echo 0 > /sys/module/snd_hda_intel/parameters/power_save

# Set the SATA to max performance
echo max_performance > /sys/class/scsi_host/host2/link_power_management_policy
echo max_performance > /sys/class/scsi_host/host3/link_power_management_policy
echo max_performance > /sys/class/scsi_host/host4/link_power_management_policy

# Make sure ondemand governor is set
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

# Enable the webcam driver
#  modprobe uvcvideo

else # Save power

# Set the disks to aggressively save power and use the lowest acoustic
# level.  Note: Currently Firefox is very poorly behaved and some
# might find these settings too aggressive.  If so, change “-S 4” to
# something larger like -S 24 (two minutes).
hdparm -B180  /dev/sda

#set the LCD bright to 60%

echo 60 > /proc/acpi/video/VID/LCD/brightness

# Change the ext3 commit times to 10 minutes.  This reduces disk
# activity
mount -o remount,commit=600 /

# Set laptop disk write mode
echo 5 > /proc/sys/vm/laptop_mode

# Manually set the iwl3945 driver to power savings.
#echo 5 > /sys/bus/pci/drivers/iwl????/0000\:??\:00.0/power_level

# Reduce disk activity by waiting up to 10 minutes before doing writes
echo 90 > /proc/sys/vm/dirty_ratio
echo 1 > /proc/sys/vm/dirty_background_ratio
echo 60000 > /proc/sys/vm/dirty_writeback_centisecs

# Set sound card power savings
echo 10 > /sys/module/snd_hda_intel/parameters/power_save

# Set SATA to minimum power
echo min_power > /sys/class/scsi_host/host0/link_power_management_policy
echo min_power > /sys/class/scsi_host/host1/link_power_management_policy
echo min_power > /sys/class/scsi_host/host2/link_power_management_policy
echo min_power > /sys/class/scsi_host/host3/link_power_management_policy
echo min_power > /sys/class/scsi_host/host4/link_power_management_policy

# Make sure ondemand governor is set
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

# Remove the webcam driver
modprobe -r uvcvideo
modprobe -r sbp2
modprobe -r ieee1394
modprobe -r uvcvideo
modprobe -r videodev
modprobe -r v4l1_compat
modprobe -r compat_ioctl32
modprobe -r v4l2_common

The script is commented, I only changed a few things from the original, it works fine, some drivers are able to set the hardware in low-power mode but it seems they don’t do by default, GNU/Linux seems to have to polish laptop distributions.

Powertop shows you the watts you’re currently using when the laptop is not connected to the AC, so I played with phc to undervolt the CPU, now I’m able to use less power for the CPU, this doesn’t decrease the performance.

You can use this tutorial to get a kernel able to undervolt the cpu, you just have to replace a module.

My original settings are:

43 35 27 19

Now they are:

24 1 1 1

Powertop shows the laptop uses less energy now and the cpu is colder at high load.

June 3, 2008

Things I don’t like about some GNU/Linux distributions

Filed under: computer, Software — Tags: , , , , , , , , , , , , — guilleml @ 12:20 pm

I’ve been trying linux distributions dor a while and there are things I like and things I don’t like. My aim was to use another distribution as my main Linux system.

Now I’m using Kubuntu 8.04 and I’ve been using Kubuntu since version 6.04 or 6.10 I don’t remember.

Some years ago I was a really Linux-geek guy, I used LFS for a while, I loved Gentoo and optimizing my system, to try new gcc flags, etc…but one day I just wanted to have my computer ready for anything I need, I couldn’t wait 6 hours untill my OOo compiles or some hours just if I want to install an IDE like Netbeans or Eclipse, they are binaries but the system require to built some libraries to run them. So that’s when I started to look for a distro with binary packages and…well…I don’t want to edit config files anymore, so the distro I was looking for had to be very user friendly, had to detect all my hardware, config it…I don’t want to spend much time configuring my system.

So I tryied some of the most famous distributions, Debian, of course, I’ve used it a lot of times, I tryied Lenny and I had some problems like a kernel bug with the DMA and my DVD writer, the system spent to boot arround 5 minutes and the writer wasn’t operative, I had to reset the device and set the DMA flag to 1 to use it, I don’t use the wirter too much but this was annoying and I didn’t want to build my own kernel.

Debian worked fine, really well, but it worked like Kubuntu, I didn’t find pretty much differences, I don’t have any stability problems with Kubuntu so I didn’t notice Debian more reliable, the fact was Debian was giving me problems with the writer and with aMule (ed2k p2p client), in the search tab, when I closed the searches I made aMule crashed all the time, it doesn’t do that in Kubuntu and my writer works fine.

Well, I had to build my atheros madwifi driver, that wasn’t much problem, make, gcc, linux-headers, madwifi-source….and all done, Kubuntu detected at first boot.

I didn’t notice any performance difference, Debian was just as fast as Kubuntu so, I already have my Kubuntu configured, the performance is the same and I avoid a pair of bugs using Kubuntu…I didn’t find a reason to change Kubuntu for Debian.

Next I tryied OpenSuse, I like KDE and OpenSuse has a name as a KDE distro, even Linus Torvalds recommends it.

I tryied OpenSuse 10.2 and 10.3, it worked great, it has a “control panel” where you can configure the system, something I liked a lot, Kubuntu doesn’t have it and I think it wont since Canonical gives priority to Gnome and the KDE version is not so nice in wizards or admin tools.

I configured some repositories, I updated the system…not much problem. The thing I don’t like was everytime you run the software install tool, it synchronizes with the repositories, son you have to wait a lot of time because the mirrors were slow, for me. And this happends everytime you run this program, so install something like amsn, close the program and run it again because you forgot to install ktorrent can cost you 15 minutes.

I had to build my atheros driver too…

I’m really comfortable with aptitude and .deb packages, yast didn’t liked me because of that updating process.

After that I installed Mandriva 2008 Spring, I installed it in a virtual machine I liked it and then I tryied in a partition. Well, I have to say Mandriva is a great distribution, really easy, it detected my wifi card, my network, I configured the repositories, updated my system…everything fine.

But there were lot of things, little things and a big thing I didn’t like.

When I updated the software repositories list it spent a lot of time, waiting, not downloading, and the mirror was in my country, I don’t know why but it was slow.

My screen was always set to 60Hz, it’s a LCD monitor that works at 1280×1024 @ 75Hz, using krandr tool I set it to 75Hz, fine, but everytime I rebooted the system, the screen was set to 60Hz again, I even edited xorg.conf but it didn’t work.

That was a little thing, there was other little things, not very important but I didn’t like it neither, there is an applet in the panel that shows you what devices are mounted to extract, mount or dismount them, there appears a floppy disk icon, I have a floppy drive but I never use it, so I disabled it in the config menu, it disappeared but, as before, it was there again when I loaded the system! I like my settings to me saved, I don’t want to spend 3 minutes setting up the environment every time I boot my computer.

Anyway, the big problem I found, the reason I don’t use Mandriva are the fonts. The rendering is so…UGLY and DIRTY that I didn’t feel fine reading them.


Free Image Hosting at


Free Image Hosting at


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There you can see the difference between fonts in Kubuntu and Mandriva.

So, I’ll try OpenSuse 11 official release, maybe they have solved the install software problem, until I found other thing I’ll be using Kubuntu, I’m tired for so much publicity ubuntu gets, but it works fine for me…for now.

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