Non-Deathmatch: Preempt v. Low-Latency Patch 178
LiquidPC writes: "In this whitepaper on Linux Scheduler Latency, Clark Williams of Red Hat compares the performance of two popular ways to improve kernel Linux preemption latency -- the preemption patch pioneered by MontaVista and the low-latency patch pioneered by Ingo Molnar -- and discovers that the best approach might be a combination of both."
co-op! (Score:2, Funny)
Oooooh (Score:4, Funny)
Interrupt priorities (Score:4, Funny)
Clearly, most RTOS designers have their priorities backwards.
Mmmm, donuts.
Re:One good way to reduce kernel latency.. (Score:4, Funny)
Honestly, I'm not trying to troll you here, but why would you WANT to run a *nix kernel on hardware that's responsible for engine timing? Especially when you apparently already have tech that works. Is the idea just to make vehicles that much harder for people to maintain? The day my mechanic keeps a sysadmin on duty so he patch my buggy Linux 4.5.3 ECU is the day I put a gun to my head and pull the trigger.
Aside from that. Way to inform the masses.
Re:I did better (Score:3, Funny)
la... (Score:2, Funny)
Re:One good way to reduce kernel latency.. (Score:2, Funny)
Low-latency and Preemptible on my Notebook (Score:3, Funny)
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In X (KDE), I can move windows around, load programs, webpages etc. without my MP3-player ever beginning to skip.
- When doing massive file IO, the MP3-player begins to skip. tar cvzf file.tar.gz bla/ is still ok, but cp -R bla1 bla2 causes massive skipping.
- When I use the notebook as a samba server,
things get worse. Still, massive skpping. Additionally, the samba becomes dog-slow and even the mouse falls asleep.
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Often times, after such phases of heavy load, the skipping and sound-distortion remains! So I have to reboot the machine from time to time to enjoy music again. Closing the player and opening it again is not enough. Somehow, under heavy load things get messed up enough to make a recovery impossible.
I did use the preemptive patch before, but performance under heavy load was even worse and the similar problems with rebooting occurred. I was using kernel 2.4.12 for preemptive and I am using kernel 2.4.17 currently. The machine is a Celeron 466 with 128 megs of ram. Still, the low-latency patch makes sense for machines that are primary for playing MP3s and reading emails (that's what my notebook is), but not for desktops with a wider variety of usage patterns. It's just not ready for primetime yet, but it's promising and fun!Worst of both worlds (Score:1, Funny)
Re:No argument here, move along. (Score:3, Funny)
They are both wrong. The correct solution is to remodulate the preemption and vent the latency through the Bussard collectors.
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Re:Oooooh (Score:3, Funny)
- preumtailable
Well, there...you...go!Re:One good way to reduce kernel latency.. (Score:2, Funny)
If you use an early development kernel in a production engine, you deserve what you get.