Tuesday, 15 June 2010
Virgin Mobile Mobile Broadband on Ubuntu Lucid Lynx
Using the Huawei E160e dongle provided, it was necessary to turn off all authentication methods except PAP, and set the APN to "virginbroadband" lowercase, via the network manager. I also had to disable my wireless (household) temporarily as it was causing chaos with the routing tables.
Sunday, 2 May 2010
Resetting the Startup Applications in GNOME
Resetting the Startup Applications in GNOME
Remove ~/.config/autostart, (or any of the *.desktop files therein containing Hidden=true).
Remove ~/.config/autostart, (or any of the *.desktop files therein containing Hidden=true).
Monday, 8 March 2010
Linux mitosis
Thursday, 25 February 2010
Linux 2.6.33
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
My courses for 2010!
SPAN1001 - Introduction to Spanish I | Undergraduate | 03/31/2010 |
COMP2410 - Networked Info Systems | Undergraduate | 03/31/2010 |
MATH2301 - Games, Graphs & Machines | Undergraduate | 03/31/2010 |
MATH3062 - Fractal Geometry & Chaos Dynam | Undergraduate | 03/31/2010 |
SPAN1002 - Introduction to Spanish II | Undergraduate | 08/31/2010 |
ENGN2221 - System Dynamics | Undergraduate | 08/31/2010 |
MATH3301 - Number Th & Cryptography | Undergraduate | 08/31/2010 |
ENGN3223 - Control Systems | Undergraduate | 08/31/2010 |
Monday, 8 February 2010
SIGALRM and the GIL
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.
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
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.
- 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.
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