[linux-audio-user] I/O scheduler for 2.6 kernel

[Mark Knecht]

I believe that you are using anticipatory. I don't know which one is
best for low latency.

You can try each one (I think) by adding a boot time option to grub.conf

elevator=deadline

or

elevator=cfq

for example.

I've been interested in this also, but not enough to try and develop a
real test. I suspect you'll have to run for a while to make a real
determination.

Good luck, and report back.

cheers,
Mark

On 9/28/05, Antonio <debian at fastwebnet.it> wrote:
> Hi to the list,
>
> I've compiled a 2.6.12 kernel in my debian system (using the debian
> sources). I want to obtain the best latency possible without using the
> realtime patch. I've noted that there are three i/o scheduler in the
> kernel config:
>
>   Device Drivers  --->
>     Block devices  --->
>       IO Schedulers  --->
>         <*> Anticipatory I/O scheduler
>         <*> Deadline I/O scheduler
>         <*> CFQ I/O scheduler
>
> I've compiled them all as built-in. Which is best for low-latency audio
> work? Can I change the scheduler while the system is running (I read it
> somewhere)?
>
> The file /sys/block/hda/queue/scheduler contains:
>
>   noop [anticipatory] deadline cfq
>
> so which scheduler am I using now? I've tried to echo cfg to that file
> but it remains the same.
>
> I appreciate any information, link or other to make light on the matter.
>
> Thanks for any answer,
>
>   ~ Antonio
>
>