Sunday, 2 May 2010

Resetting the Startup Applications in GNOME

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Resetting the Startup Applications in GNOME

Remove ~/.config/autostart, (or any of the *.desktop files therein containing Hidden=true).

Monday, 8 March 2010

Linux mitosis

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Evidently Ubuntu has transcended its origins. This is analogous to listing BSD instead of Mac, and NT instead of all the variants of Windows.

Thursday, 25 February 2010

Linux 2.6.33

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Stuff I think is interesting in this release:
  • Nouveau: This is still premature, and not of much use until the supported features are a super set of those the proprietary drivers provide. (In particular 3d support, and video acceleration). However now that it's been accepted into staging, one can hope that work on this feature will accelerate.
  • Recvmmsg(): Vectored system calls are always interesting, particularly when doing things on a massive scale. This looks to the first of many networking system calls to be vectorized, allowing for even greater throughput for services with high connection/datagram counts.
  • Nintendo/Wii drivers: The more mainstream the hacking of common computer hardware gets the better. Need I say more?
  • Reiserfs de-BKLification: This sounds promising. Reiserfs has fallen by the wayside since Ext4 came out. The presence of undesirable locking on SMP machines will not help that. With reiser4 nowhere to be seen, reiserfs needs tweaks such as this to remain competitive.

Monday, 22 February 2010

2010 Courses at Uni

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My courses for 2010!

SPAN1001 - Introduction to Spanish IUndergraduate03/31/2010
COMP2410 - Networked Info SystemsUndergraduate03/31/2010
MATH2301 - Games, Graphs & MachinesUndergraduate03/31/2010
MATH3062 - Fractal Geometry & Chaos DynamUndergraduate03/31/2010

SPAN1002 - Introduction to Spanish IIUndergraduate08/31/2010
ENGN2221 - System DynamicsUndergraduate08/31/2010
MATH3301 - Number Th & CryptographyUndergraduate08/31/2010
ENGN3223 - Control SystemsUndergraduate08/31/2010

Monday, 8 February 2010

SIGALRM and the GIL

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had some weird lag issues in nethogs2. i was firing setitimer SIGALRMs to keep things in check, every 0.25s. but strangely some alarms would arrive 6s or more apart...

DEBUG:nethogs2(134):Alarm triggered at 1265561284.348955
INFO:proctab.py(108):Unknown process: Connection(local=('192.168.0.1', 520), remote=('192.168.1.255', 520), family=2, protocol=17)
DEBUG:nethogs2(134):Alarm triggered at 1265561293.166447

which is HIGHLY bizarre, as the OS does this shit, and signals date back so far that you don't fuck with them. they arrive, on time, no excuses.

so i ran python profiler to see wtf is going on:

matt@stanley:/media/data/source/anacrolix/projects/nethogs2$ sudo python -m cProfile -s cumulative ./nethogs2

and i get this

347158 function calls (347141 primitive calls) in 26.807 CPU seconds

all dandy until i see this in the printout:

12 24.737 2.061 24.743 2.062 {_pcap.pcapObject_dispatch}

a C function is using up 90% of my time, LOCKING OUT the signal handling!!

it turns out the call to pcap_dispatch is blocking, and i suspect it was taking the GIL with it. i'd also guess that signals are delivered to your python callback, only if the GIL can be claimed. changed the timeout from blocking to 1ms... problem fixed.

Tuesday, 8 December 2009

Ubuntu 9.10 - Karmic Koala

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The Good:
  • This is the first release in which Pulseaudio has been usable enough to remain installed. Configuration is relatively easy and reliable, with only very occasional problems.
  • Default desktop effects are reliable, and don't cause loss of functionality which previously included such things as: Loss of expected Metacity behaviour and lagginess when watching videos.
The Bad:
  • Not exactly the fastest installer in the world.
  • Installing the boot loader to the root partition has been, and still doesn't work as expected.
  • Replacing Pidgin with the feature-lacking Empathy as the default instant messenger was not a good move. Empathy lacks support for file-transfers and voice and video for common protocols, nor does it work behind proxies, which are common for institutional users.
Overall, not as good as Jaunty. 7/10.

Fedora 12

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The Good:
  • Plymouth is demonstrated brilliantly, seamless video mode transitions from kernel load until shut down.
  • Installer is very fast, by means of image copying. Configuration is delayed where possible to the first boot in the new installation, where the environment is far more responsive.
  • Automatically detected heterogeneous dual monitor configuration.
  • RPM Fusion is easy to set up.
  • KDE4 configuration is the best I've seen in a binary distro to date, and the GNOME setup is very clean and snappy.
The Bad:
  • New partitions can only be positioned at the beginning of free regions.
  • BIOS RAID metadata is not ignored, and can crash the installer.
  • The updater is slow, and doesn't provide much information on what's going on.
  • There's no way to configure package sources in a GUI.
  • No proprietary packages, and no immediate documentation is provided on how to obtain these (MP3 codecs, nVidia drivers), but RPM Fusion can alleviate this a little.
  • It can be difficult to identify exactly which package to install, with the enormous description text being more visible than the package name itself.
  • Default IM is Empathy (which isn't a feature parity replacement for Pidgin yet).
  • I experienced some bugs in Rhythmbox which could be related to choices or misconfiguration in GTK+ or some other component.
Summary:

Not yet as usable as Ubuntu, even considering the policy surrounding proprietary software and RPM Fusion. However this is the best Fedora release since Fedora 7.

Score:

5/10.