[pulseaudio-discuss] PulseAudio Painfully Slow

[Alexander E. Patrakov]

14.07.2014 14:04, Benny de von Ausfern пишет:
>>Please add this to the kernel command line to work around the kernel bug:
>>intel_iommu=igfx_off
>
> I am not sure if I added the kernel command line properly. The reason is
> that I am new to EFI bootloader and I'm not really sure how to configure
> reFind to do that, but I tried.
> This is the new alsa-info.sh: http://pastebin.com/m1NRTZTh

I have looked. At least this error (that was in your old log) has 
disappeared:

snd_hda_intel 0000:00:1b.0: Unstable LPIB (131072 >= 8192); disabling 
LPIB delay counting

So please keep the option.

>>Second, you have overrides of the model that are unnecessary for your hardware. 6stack is definitely not applicable to Haswell HDMI. So, remove all snd-hda-intel module parameters.
> That load module line was merely intended to set the HDMI as Card#1
> rather than Card#0, so that ALSA would not pick it by default. Thanks
> for pointing out, I will remove the 6stack from there (I don't remember
> why I put it). I did completely remove it from my modprobe.d/alsa.conf
> though (temporarily).
>
> I tested everything again with this configuration. Nothing changed. The
> slowdown feels and look the same.

Thanks for the information. This confirms that it is not only about the 
known IOMMU issue.

As for swapping the two snd-hda-intel cards, the magic module parameter 
is: index=1,0

i.e. it takes a comma-separated list of integers, one for each card. You 
can identify other parameters that take lists of integer or strings by 
looking in your alsa-info dumps.

>  >It is not "with nothing else going on" - there is pavucontrol, which
> causes PulseAudio to enable the peak meter. And with that, it's
> perfectly reasonable for PulseAudio to eat 6% of your CPU.
> HOWEVER...
> Closing pavucontrol SIGNIFICANTLY reduces the slowdown. Well well well,
> what do you have in that peak meter of doom there? Pulseaudio still
> slower than ALSA, but it changed from "unplayable" to "playable with
> moderately lower fps". Still not ideal though.

That's a breakthrough, because we now know that there are two problems 
(one related to the peak meter of doom and one unrelated), to be 
profiled separately. Profiling instructions will be sent later today, 
when I return from work.

-- 
Alexander E. Patrakov