This series of documents explore how the memory is used by the Xorg server. They aim to eventually shrinks the memory footprint of the server and its related components, like X clients, modules being loaded and drivers. Embedded devices with constrained resources are the main focus here. All texts are mostly based on x86 and ARM architectures, under Linux 2.6.33 with Xorg from upstream.

Overview

One way to analyse aspects of memory usage of a given program is to scrutinize its object data. Object data contains executable code and static data. Both are of little interest from the process memory management point of view given their layout is determined by the compiler and does not change during process execution. However, we can deduce some nice informations about the object. For instance, from Xorg object we are able to get some statistics about the code, identify its structure and point out architectural mistakes just looking into.

For the first time in life, Xorg is being used in a single platform and for a given device only (other devices have used an X11 implementation but using other non-canonical servers, such kdrive’s based - Tiny-X).

Previously Xorg was being packed to run in a huge amount of OSes - mostly Linux and Unix-like distributions - with the characteristic of be architecture portable and able to run on a huge set of video and input devices. In terms of software, this means an extensive amount of code able to cover all of this mentioned. But this is far from the needs of a small and single platform device.

I like UI and I’m not gay.

Some time ago someone posted a comment, complaining about the white fonts over the dark background in my blog, which makes the read be difficult. The guy teased me, recommending an ironic page where shows how hard is to read texts like this. He was right…

So now I changed wordpress to a totally opposite theme called “White as Milk”. Yay, total white and easy to read now! Let’s see how long I’ll get sick of that interface.

Just a thought is this something that should be deleted? This seems to be using about 7% of my RAM

I don’t have words for it.

Portland, OR

I was so proud for the forth time be part of the X crew, this time in Portland. Really amazing the city. I had the opportunity to play tourist and visit some nice places.

My X conferences

BTW, I just collect the photos of all four X conferences that I’ve attended. It’s not much photos but there’s some funny things :)

X on embedded

The cool thing of the work that I’m doing at Nokia is that I can publish and discuss mostly all X fun with the open source communities. “Mostly” because, for the last device - the N-shiny-and-awesome-900 - for instance, the video driver is closed (provided by Imagination), so we cannot comment much regarding such driver stack :( C’est la vie.

So last week I posted on lkml an old patch that we were carrying for a long time in the Linux community. It basically brings the multiple (old) video cards functionally again on Linux and X server (and this time doing on the right and beauty way). For the people that was following multiseat implementations, this is a HUGE step: we will finally be able to discard the old and ugly hack (a mix of Xorg, several Xephyr servers + evdev) and and go to a clean way, starting multiple X servers in parallel. Cool! Well, not that much, because it might take some time to be in your beloved distribution :)