<div id="geary-body" dir="auto"><div>Hi,</div><div><br></div><div>I checked out the upcoming kernel for Fedora 35:</div><div><br></div><div><div>[ 0.069100] Kernel command line: BOOT_IMAGE=(hd2,gpt2)/boot/vmlinuz-5.16.2-200.fc35.x86_64 root=UUID=7812bc02-a2ea-4335-bc7b-636e1612841a ro rhgb quiet threadirqs preempt=full</div><div>[ 0.069632] Dynamic Preempt: full</div></div><div><br></div><div>This week is kernel test week. So probably next week, we will have a kernel with dynamic preemption in Fedora.</div><div><br></div><div>Best,</div><div>Nils</div><div><br></div></div><div id="geary-quote" dir="auto"><br>Am Di, 11. Jan 2022 um 17:55:04 -0800 schrieb Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>:<br><blockquote type="cite"><div class="plaintext" style="white-space: break-spaces;">On 1/10/22 3:06 PM, Fernando Lopez-Lezcano wrote:
...
<blockquote>==== System A: kernel 5.14.8-200.1.motu.fc34.ccrma (preempt=full)
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I did a local build for fc34 of the latest Koji 5.16.0 Fedora source package and installed it in my "System B". At least in that source package CONFIG_PREEMPT_DYNAMIC is set to "y" (yay!, cross fingers it stays that way!) and I can switch to preempt=full when booting without any further tweaks.
The kernel no longer prints the status when booting, but "cat /sys/kernel/debug/check/preempt" confirms the system is in preempt=full state.
The latency numbers I see on my first test and reported by cyclictest are not quite as good as "System A" (running 5.14.8), but they are good.
-- Fernando
PS: Anyone knows how to convince pipewire to let go of an audio interface? That is, not use it anymore? I'm trying the Motu driver and I would like to remove the snd_usb_audio kernel driver to reload the motu driver - long story of why, and it is not easy as the driver is in use by pipewire...
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