Fwd: [pulseaudio-discuss] Distribution kernels and glitch-free (Packagers, read this!)

[Andy Whitcroft]

On Mon, Feb 23, 2009 at 09:31:05AM +1100, Luke Yelavich wrote:
> I would like to respond to Lennart about what he has said in the below forwarded message, particularly relating to the options that need changing to get good audio performance with glitch free pulseaudio. I am sure there are reasons why the generic kernel has settings other than what is listed here, so I would like to know the kernel team's reasons why we cannot/should not change the below mentioned settings to the suggested values.

Neither of those settings would be seen as a standard configuration
kernel wise, and generally we do aim to use options at the recommended
upstream values.

It sounds like pulse audio glitch free is playing just-in-time buffer
fills based on latency guanrentees that simply do not exist in the
mainstream kernels.

That said I am somewhat supprised that we are seeing such poor latency
performance in the kernel right now.  I note there is another thread on
the kernel list[1] which talks about poor scheduler latency triggered
by a bug in the scheduler.  It would be worth testing with the fixes
nominated there.

-apw

[1] Subject: Idle-priority scheduling fix
    Bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/276476