Random Notes on GNOME

A while ago there was a known issue with several Dell and HP laptop models shipped with Nvidia GPU. As in many issues, it can pass unnoticed until it happens to you. Nvidia provided chips that were overheating and failing. There were several symptoms, such as vertical lines in text mode (even when showing the BIOS message), black screens when starting the graphical mode or psychedelic colors while working in a session (hanging the OS). Of course, it failed after the warranty expired and this particular model was not included in any recall.

GNOME Psychedelic after a random crash on Monday 22

Flipping Nvidia

The first symptoms were triggered when accessing some operation or “feature” using Nvidia’s driver, and it happened either using Linux or the pre-installed OS. Therefore, it was a hardware problem. Anyway, it was possible to boot in single mode, so, the next step was trying X using the nouveau driver in xorg.conf and it worked! (oh yeah, less is more!). All this happened to my wife when she was in Canada back in 2009, so the credits for the trick belong to her.

After Googling a bit, we figure out it was the famous overheating issue that melt some contacts in the GPU (nothing related with the lid button, though. Just the “good” quality of the Nvidia chipset :-).

It was a bit weird that the problem was not triggered using the nouveau driver. But weirder was when, back in Chile some months later and without any rational explanation, she booted the laptop in the pre-installed OS (that is the irrational part). She had forgotten the issue and the laptop failed again. Ok, no problem, it was the issue with the driver, we thought. However, in Linux, X could not start anymore (that is the weird part). After giving kindly our best wishes to Bill, we decided to buy another laptop. No more Nvidia, but we still trusted in Dell.

The return of the King

Before we moved to Canada in 2010, we decided to sell the useful parts of the old laptop (everything but the motherboard). As some months before, my wife disassembled the laptop, cleaned each component, and later, she wanted to give it a try… and the flipping laptop worked again! No vertical lines in text mode, just like the good old times. Obviously, we only tried the nouveau driver. Then, that laptop became my laptop because I did not own one (I used to use the one provided by my employer). So far, so good.

Nothing lasts forever

Some months later, in August, the laptop started to fail again, randomly. In its best times it worked with 256 colors at 1024×768, but commonly the maximum resolution was 800×600. It was like having a tablet, just a bit heavier and not cool at all. However, it was getting worse and was hanging the system continuously.

[   20.999392] [drm] nouveau 0000:01:00.0: Detected an NV40 generation card (0x046800a3)
[   21.000840] [drm] nouveau 0000:01:00.0: Attempting to load BIOS image from PRAMIN
[   21.066680] [drm] nouveau 0000:01:00.0: ... BIOS checksum invalid
[   21.066685] [drm] nouveau 0000:01:00.0: Attempting to load BIOS image from PROM
[   21.066691] [drm] nouveau 0000:01:00.0: ... BIOS signature not found
[   21.066694] [drm] nouveau 0000:01:00.0: Attempting to load BIOS image from PCIROM
[   21.066908] [drm] nouveau 0000:01:00.0: ... BIOS checksum invalid
[   21.066910] [drm] nouveau 0000:01:00.0: Attempting to load BIOS image from ACPI
[   21.066914] [drm] nouveau 0000:01:00.0: ... BIOS signature not found
[   21.066917] [drm] nouveau 0000:01:00.0: Using BIOS image from PRAMIN
[   21.133482] [drm] nouveau 0000:01:00.0: No known BIOS signature found
[   21.154946] nouveau 0000:01:00.0: PCI INT A disabled

At that time I was not in a position to afford a new computer and the only replacement parts at a reasonable price were in China, but I did not have a credit card and I was unsure about the custom office in Canada.

The hot air solderer to the rescue

In my all search, a friend of mine recommend me some videos where people baked the motherboard during 10 minutes at 200°C (yes, baked the motherboard in a oven). After following some links, and asking here and there, I got to the hot air solderers and some videos in Youtube School™. That sounded more reasonable… if I only could get one for some minutes.

When the term started in September, I went to IT support and they had one. I explained what I wanted to do to the technician, and he brought some old cards to show me how the hot air solderer worked and to gain confidence with the tool. I realized it takes a while to melt the components. So, I thought it was safe enough. Finally, I took off the motherboard and applied hot air to the Nvidia chipset some minutes (10-15 minutes).

Me applying 600°F (315°C) on the Nvidia GPU

And it worked! Always with the nouveau driver. It lasted around 5,5 months, until some days ago when the laptop started to fail again.

Thus, yesterday I repeated the procedure and the laptop is working again. I only have to pay attention to the system temperature to force the CPU clock to run slower, which is pretty fine with GNOME applets.

A group of researchers leaded by Jim Herbsleb got in contact with GNOME Foundation some months ago in order to research how communities works, how a volunteer become an active contributor, among others.

In the following days, developers (committers) will receive and invitation to complete a survey that would not take more than 20 minutes (or even less). However, the participation in the study is completely voluntary.

It worth to mention that the results will be shared with the community, and we will insist on that.

At last but not least, the original plan included a joint survey to help set the Foundation goals, which will not be the case. However, we are looking forward to receive help from this team of researchers in the near future.

A few days ago, Claudio wrote about the time Eog spent saving the filename of a recenlty used image into ~/.recently-used.xbel. The reason: ~/.recently-used.xbel was too big. If I remember correctly, the FileChooser used to have a similar issue in the past.

Going down from 5.8 MiB to 1.8 MiB, through deleting all those items whose files does not exists, seems to be a good improvement. I wanted to go a bit further and I wondered ¿How many recent files does an application really need? (sorry, not that further :-) I do not think more than 10 per application, but let me know if I am wrong.

I wrote my own version of Claudio’s program with that matter in mind. And my ~/.recently-used.xbel file went down from 1.2 MiB to 54 KiB. Before to go to the script, let me show you the numbers I got in a computer with less than two month of non intensive use:

gpoo@pendragon:~$ python clean-recently-used.py -v
Summary:
     1 Reproductor de películas Totem
     1 Glade
     4 GNU Image Manipulation Program
     4 Navegador web
     9 Visor de documentos Evince
     9 File Roller
    14 Web Browser
    15 Gnumeric Spreadsheet
    26 gedit
    34 Administrador de archivos
    36 Evince Document Viewer
    52 Totem Movie Player
   292 File Manager
  1151 Eye of GNOME Image Viewer

Whenever I run Eog, it always shows me only the last 5 files I opened before. Why does it need 1146 extra items stored?

Nevermind. The script I wrote is simple. It deletes those files that does not exists (the same strategy used by Claudio’s program), but it also deletes those files that are not so recently used, and I got the following numbers:

gpoo@pendragon:~$ python clean-recently-used.py -v
Summary:
     1 Glade
     3 GNU Image Manipulation Program
     4 Navegador web
     8 File Roller
     9 Visor de documentos Evince
    10 Totem Movie Player
    10 Eye of GNOME Image Viewer
    10 Web Browser
    10 Gnumeric Spreadsheet
    12 Evince Document Viewer
    13 Administrador de archivos
    14 gedit
    41 File Manager

Now you can put the script to be executed when you start your session or you can program it as a cron task.

If you are only interested in getting a summary, you can run the script just using the option -v.

Thumbnails are created by applications and thanks to a proposed draft are shared among desktops. But, it doesnot mean that every thumbnail stored in your home directory is useful for the purpose they were created. Some of them points to a file that doesnot exists anymore, some of them are broken images, and some of them were created by applications that doesnot respect the proposed draft.

Basically there are two size of thumbnails: normal (128×128 pixels) and large (256×256 pixels). Each thumbnail must contains at least two pairs of key/value, one of them is the URI of the original file and the another one is the last time the file was modified.

To get the file name of a thumbnail a MD5 sum must be applied to its URI. If you move the file to a new location, then the name of the thumbnail must be updated (also its metadata).

When you delete a file through Nautilus, this file is moved to the Trash folder. Furthermore, its thumbnail must be updated. Nautilus does it right, which is good. But, when you expunge the Trash, only the original file is deleted, not the thumbnail; which is bad, but easy to fix.

On the other hand, when you rename a folder, the next time the folder will be visited (in this case under a new name), the thumbnails will be regenerated, because for each URI there is no a thumbnails associated. Now, you have two thumbnails stored for the same file, but only one is valid. If you repeat this step often, your .thumbnails filder will get polluted of useless thumbnails.

Instead of renaming the folder, you can create a new folder, then move the group of files there, and finally, delete the old one. In this case Nautilus will not regenerate the thumbnails, it will update the thumbnails correctly. At least in the first hiearchy (I have not test it deeply).

The worst case happens when the files are moved or deleted by a non free desktop compliant (or kind of compliant) application, let’s say the shell. The thumbnails associated to those files will not be updated or deleted. (inotify to rescue?).

The average for a normal thumbnail is 25Kb of space while for a large one is 75Kb. If you maintain a lot of pictures in a long period of time (with all the file management involved), probably you have enough space wasted by useless thumbnails.

At least, I had. And I have the feeling that some other people, too. A time to live for thumbnails was requested, as is filed in bugzilla #150483.

Instead of delete my old thumbnails, I prefer to delete only the useless ones (in the sense of my first paragraph). So, I wrote a little script in Python (shorter than my comment) that estimate how much space I am wasting because of useless thumbnails.

After the success of “Code Monkey at Work”, where Rupert was the young hero of the movie, Rupert was invited to participate in a cameo of “Aardvark’d: 12 weeks with geeks”, a documentary film (idea of Joel Spolsky) of the whole process to build copilot (the simplest way to use VNC trhought a reflector; full of features with a simple user interface, and a better name).

Rupert in the documentary
(Rupert also appears in the trailer)

I just received my copy on Saturday 10 and I watched it the same afternoon. Interesting, even if you agree or not of what Joel usually writes about software development.

Anyway, I thought Fog Creek was bigger than I realized it is; and I was not expecting their concerns about risks in their first days (probably the same happened for Ximian, Fluendo and other related companies).

A keynote of Joel Spolsky could be very interesting indeed. Or have a short documentary of our community (we have the chance at GUADEC, Boston Summit, and so on).

As far as I have my own space to store my writings I decided to use this space to write some of my GNOME’s related notes.

Also, my main blog it is written in Spanish and I will follow writing there in my native language, because I know it is read by many people who only speaks in Spanish.