When booting linux next-20250711 (with CONFIG_PREEMPT_RT=y) on my MSI Alpha 15 Laptop running debian sid amd64 the boot process hangs with the last messages displayed on screen being:
fbcon: amdgpudrmfb (fb0) is primary device Console: switching to colour frame buffer device amdgpu: 0000:08:00.0: [drm]fb0: admgpudrmfb frame buffer device after some time (about 60s) this error messages appears (hand copied from screen, not entirely accurate) rcu_preempt self detected stall with call trace run_irq_workd smpboot_thread_fn kthread ? kthreads_online_cpu ? kthreads_online_cpu ret_from_fork ? kthreads_online_cpu ret_from_fork This only occurs when compiling with CONFIG_PREEMPT_RT=y. I bisected this and found the first bad commit to be 3284e4adca9b ("rcu: Fix rcu_read_unlock() deadloop due to IRQ work") Reverting this commit in next-20250711 fixes the issue for me. Hardware: $ lspci -nn 00:00.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne Root Complex [1022:1630] 00:00.2 IOMMU [0806]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne IOMMU [1022:1631] 00:01.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge [1022:1632] 00:01.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe GPP Bridge [1022:1633] 00:02.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge [1022:1632] 00:02.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne PCIe GPP Bridge [1022:1634] 00:02.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne PCIe GPP Bridge [1022:1634] 00:02.3 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne PCIe GPP Bridge [1022:1634] 00:02.4 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne PCIe GPP Bridge [1022:1634] 00:08.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge [1022:1632] 00:08.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Renoir Internal PCIe GPP Bridge to Bus [1022:1635] 00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller [1022:790b] (rev 51) 00:14.3 ISA bridge [0601]: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge [1022:790e] (rev 51) 00:18.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 0 [1022:166a] 00:18.1 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 1 [1022:166b] 00:18.2 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 2 [1022:166c] 00:18.3 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 3 [1022:166d] 00:18.4 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 4 [1022:166e] 00:18.5 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 5 [1022:166f] 00:18.6 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 6 [1022:1670] 00:18.7 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Cezanne Data Fabric; Function 7 [1022:1671] 01:00.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Upstream Port of PCI Express Switch [1002:1478] (rev c3) 02:00.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Downstream Port of PCI Express Switch [1002:1479] 03:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 23 [Radeon RX 6600/6600 XT/6600M] [1002:73ff] (rev c3) 03:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21/23 HDMI/DP Audio Controller [1002:ab28] 04:00.0 Network controller [0280]: MEDIATEK Corp. MT7921K (RZ608) Wi-Fi 6E 80MHz [14c3:0608] 05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 15) 06:00.0 Non-Volatile memory controller [0108]: Kingston Technology Company, Inc. KC3000/FURY Renegade NVMe SSD [E18] [2646:5013] (rev 01) 07:00.0 Non-Volatile memory controller [0108]: Micron/Crucial Technology P1 NVMe PCIe SSD[Frampton] [c0a9:2263] (rev 03) 08:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] [1002:1638] (rev c5) 08:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Renoir Radeon High Definition Audio Controller [1002:1637] 08:00.2 Encryption controller [1080]: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) Platform Security Processor [1022:15df] 08:00.3 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne USB 3.1 [1022:1639] 08:00.4 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Renoir/Cezanne USB 3.1 [1022:1639] 08:00.5 Multimedia controller [0480]: Advanced Micro Devices, Inc. [AMD] Audio Coprocessor [1022:15e2] (rev 01) 08:00.6 Audio device [0403]: Advanced Micro Devices, Inc. [AMD] Family 17h/19h/1ah HD Audio Controller [1022:15e3] 08:00.7 Signal processing controller [1180]: Advanced Micro Devices, Inc. [AMD] Sensor Fusion Hub [1022:15e4] $ head /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 25 model : 80 model name : AMD Ryzen 7 5800H with Radeon Graphics stepping : 0 microcode : 0xa50000c cpu MHz : 2826.830 cache size : 512 KB physical id : 0 Bert Karwatzki