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Linux FGLRX-driver does not work with Low-Latency kernels Debian stable

Question asked by glaesera on Nov 12, 2015

Hello, I am new to AMD-Support, and I know you guys don't want to provide any support for for Debian, but in fact my question is not really Debian-specific, but Linux-specific.

I have been using Low-Latency kernel, it means on Debian, you configure the sources yourself and build a kernel-package, pre-built versions are not available.

Changing from open-source Radeon-driver respectively AMD-GPU kernel-driver to FGLRX I found, it is not workable with low-latency-kernel. I wonder why this is the case, because the Low-Latency feature of Linux is in mainline, it is not an external patch, like Realtime-Linux, so it should work probably. I am referring to this kernel-version, currently in Debian stable:

i A linux-image-3.16.0-4-amd64           

- Linux 3.16 for 64-bit PCs

> Package: linux-image-3.16.0-4-amd64

> State: installed

> Automatically installed: yes

> Version: 3.16.7-ckt11-1+deb8u5

> Priority: optional

> Section: kernel

> Maintainer: Debian Kernel Team <debian-kernel@lists.debian.org>

> Architecture: amd64

> Uncompressed Size: 163 M

> Depends: kmod | module-init-tools, linux-base (>= 3~), debconf (>= 0.5) | debconf-2.0,

>      initramfs-tools (>= 0.110~) | linux-initramfs-tool

> PreDepends: debconf | debconf-2.0

> Recommends: firmware-linux-free (>= 3~), irqbalance

> Suggests: linux-doc-3.16, debian-kernel-handbook, grub-pc | grub-efi | extlinux

> Breaks: at (< 3.1.12-1+squeeze1), initramfs-tools (< 0.110~)                            
> Provides: linux-modules-3.16.0-4-amd64                                                  
> Description: Linux 3.16 for 64-bit PCs                                                  

>  The Linux kernel 3.16 and modules for use on PCs with AMD64, Intel 64 or VIA Nano processors. 

>                                                                                               

>  This kernel also runs on a Xen hypervisor.  It supports both privileged (dom0) and unprivileged   

>  (domU) operation.

> Homepage: https://www.kernel.org/

 

 

FGLRX for Linux 4.x does not exist yet.

I can give you the configuration, I used, and logfiles but it is probably not necessary, someone there will be able to check 'Low-Latency' instead of 'Voluntary Preemtion' (Desktop), build a kernel-package, I guess, and see for yourselves it is not workable with FGLRX. Or simply try it out on Ubuntu, they provide ready-made low-latency kernels.

 

I am looking forward to AMD releasing a free and open-source version of OpenCL drivers, currently trying to get started with this.

  

> kingfish Expert 10-Nov-2015 10:34 (in response to glaesera)

>

> You probably should move your question to the Linux forum > Linux

 

Kingfish suggested, I should ask this:

Linux FGLRX-driver does not work with Low-Latency kernels Debian stable

at Linux-forum, moving my post did not work out so beautifully, editing the forums also seems to be somewhat slow to me, i.e. there is too much latency, possibly it's network-latency. You (AMD-US) really should consider to better decentralize your services and have some data-centers /computation-centers here in Europe, it has quite a bunch of advantages, also improves usability for non-US users.

Now, as I am at the Linux-forum I also want to point you at my Debian-bugreport there:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800674

It has been closed, but I think nothing has been done about it, it is probably too hardware-specific, so Debian cannot do anything about, also the stock-kernel is not affected by it.

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