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#26 2022-12-25 15:01:54

liquibyte
Member
Registered: 2022-12-24
Posts: 2  

Re: [SOLVED] Daedalus and access to efivars

GlennW wrote:
liquibyte wrote:

If you are using an rt kernel, none of this works.  I've been struggling for 3 days now trying to get the kernel to boot efistub and couldn't figure out how in the world I was booting uefi but efivarfs wasn't mounting.  I use the rt kernel due to using my system for playing guitar.  Doing a diff on the kernel config files reveals that in the rt kernel, CONFIG_EFI_DISABLE_RUNTIME=y is set.  Is there a reason for this in rt vs. default?

Edit: Nevermind

https://www.kernelconfig.io/config_efi_disable_runtime

The EFI runtime services are disabled by default when PREEMPT_RT is
enabled, because measurements have shown that some EFI functions calls
might take too much time to complete, causing large latencies which is
an issue for Real-Time kernels.

I'd hack it! And test it on the machine (same hardware) and see if your system has any lockups.

It looks like a design flaw.
I wanted to run in real time for music (DAW) but could not use the graphics card memory or gpu because of the rt kernel and nVidia conflicts.
Sad really.

You can override the behavior by adding efi=runtime to the kernel options.  PREEMPT_RT kernels have this off by default in their config files due to the above mentioned measurements.  My concern is that once everything is loaded by EFISTUB exactly how many EFI function calls happen in the course of using the system and how would that affect realtime.  I'll report back if I find any negatives.

As for your DAW issue, all I can say is that up until 4 days ago, I was running a 1050ti with the nouveau driver and the rt kernel with no xruns when using guitarix.  I don't record so I can't really speak to that as my issue with nvidia cards.  I could never get their nonfree driver to load but didn't worry about it too hard TBH.  I got a decent bonus this year so I just got a Radeon RX 6650 XT last Thursday because I couldn't do blender without significant frustration and needed it to do CNC with.  The blendercam plugin is fairly decent and, once you learn a few vagaries, blender puts freecad to shame.  I'd say my advice would be to ditch nvidia as amd seems to give a damn if it's at all possible for you.  My new card cost $310 but it was well worth it IMHO.  It's a XFX Speedster QICK308 Radeon RX 6650XT if you might be wondering.

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#27 2022-12-25 23:22:22

GlennW
Member
Registered: 2019-07-18
Posts: 313  

Re: [SOLVED] Daedalus and access to efivars

liquibyte wrote:
GlennW wrote:
liquibyte wrote:

If you are using an rt kernel, none of this works.  I've been struggling for 3 days now trying to get the kernel to boot efistub and couldn't figure out how in the world I was booting uefi but efivarfs wasn't mounting.  I use the rt kernel due to using my system for playing guitar.  Doing a diff on the kernel config files reveals that in the rt kernel, CONFIG_EFI_DISABLE_RUNTIME=y is set.  Is there a reason for this in rt vs. default?

Edit: Nevermind

https://www.kernelconfig.io/config_efi_disable_runtime

The EFI runtime services are disabled by default when PREEMPT_RT is
enabled, because measurements have shown that some EFI functions calls
might take too much time to complete, causing large latencies which is
an issue for Real-Time kernels.

I'd hack it! And test it on the machine (same hardware) and see if your system has any lockups.

It looks like a design flaw.
I wanted to run in real time for music (DAW) but could not use the graphics card memory or gpu because of the rt kernel and nVidia conflicts.
Sad really.

You can override the behavior by adding efi=runtime to the kernel options.  PREEMPT_RT kernels have this off by default in their config files due to the above mentioned measurements.  My concern is that once everything is loaded by EFISTUB exactly how many EFI function calls happen in the course of using the system and how would that affect realtime.  I'll report back if I find any negatives.

As for your DAW issue, all I can say is that up until 4 days ago, I was running a 1050ti with the nouveau driver and the rt kernel with no xruns when using guitarix.  I don't record so I can't really speak to that as my issue with nvidia cards.  I could never get their nonfree driver to load but didn't worry about it too hard TBH.  I got a decent bonus this year so I just got a Radeon RX 6650 XT last Thursday because I couldn't do blender without significant frustration and needed it to do CNC with.  The blendercam plugin is fairly decent and, once you learn a few vagaries, blender puts freecad to shame.  I'd say my advice would be to ditch nvidia as amd seems to give a damn if it's at all possible for you.  My new card cost $310 but it was well worth it IMHO.  It's a XFX Speedster QICK308 Radeon RX 6650XT if you might be wondering.

Thank you. It's when recording that The system requires the latency patch to monitor the recording in real time with the playback. But, I don't do too much multi-tracking these days.

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