Ubuntu

difference between boot options Lowlatency and Generic?

Asked by chunchengch

I have many options to boot Ubuntustudio, but I don't understand what is the difference between options "Ubuntu, kernel 2.6.20-15-lowlatency" and "Ubuntu, kernel 2.6.20-15-generic"?

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Benoit Malet
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Istvan Szekeres (szekeres) said : 		#1

Hello,

there are certain functions of the Linux kernel that may take too much time. If an audio application is running (e.g. playback) while such a function is invoked, it may result in scattering in the audio playback - as the playback application does not get the possibility to feed data to the sound card because the "slow" kernel function is running instead.

Low latency kernels are ensured that the kernel do not do anything that could result in such a situation.

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chunchengch (chunchengch) said : 		#2

Hi,

Do you mean if I don't need playback function and if I prefer a "faster" kernel function, it is better for me to boot Ubuntustudio with "Ubuntu, kernel 2.6.20-15-generic" for better performance?

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Best Benoit Malet (benoit-malet) said : 		#3

Hello !

Low Latency is about the "preemption" of the kernel (this is an option when building a custom kernel).

Preemption point are the times where a process can interrupt what the kernel is currently doing to do it's own stuff ... Typically, for servers, you use fewer preemption points, as you don't need much responsiveness (on a process point of view).

In the field of Ubuntustudio, I guess it's made for the CPU time consuming tasks like video authoring. LowLatency will help you use your computer in a more flexible way, yet a bit less stable and rapid.

So it's a matter of knowing what you need : more performance for single process (generic) or more flexibility (LowLatency)

Hope this clarifies a bit the concept.

Regards,
Benoît

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chunchengch (chunchengch) said : 		#4

Thanks Benoit Malet, that solved my question.