Improving OOTB performance

Len Ovens len at
Mon May 14 21:11:18 UTC 2012

On Mon, May 14, 2012 1:07 pm, Sergey \"Shnatsel\" Davidoff wrote:

>> lets kill swap.
> No swap at all sounds like overreaction. You'd better decrease swappiness
> and swap to zram if really needed.

My experience was with swappiness set to 10. I have seen 1 suggested
though. My problem is that while most audio apps use memlock... qjackctl
does not. (maybe that is what I need to get rid of...) I have not tried
using patchage instead. (once jack is running the only use for qjackctl is
making connections)

> Swapping to zram has no noticeable
> overhead on my machine, and it allows to fit 3+ Gb of data into my 2Gb RAM
> if I need it, and only after that falls back to disk swap. Disk swap is
> used only for hibernation nowadays; swapping executable code to disk
> commonly referred to as "swapping death".

Thats qjackctl with very many softsynths running. It freezes "forever".

Swappiness is something we can set and forget rather than changing for
different modes. It seems large values of swappiness are good for servers
but not desktops in terms of responsiveness.

> This is one of those areas where each user needs to be able to find out
>> what the options are and set their machine up to meet their
>> requirements.
>> US could help by having a great setup tool that makes this easy
>> (easier).
> I believe ulatencyd is what you need for automating this. It's an epic
> tool.

It would have to be automated. Reading ulatencyd docs is eyes glaced over
stuff even for someone who knows some stuff about kernels :-)

This is not a complaint. Just it would have to be set up before shipping.


Len Ovens

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