With kernel 5.5.13, dmesg shows following: [ 3272.084146] ------------[ cut here ]------------ [ 3272.084155] WARNING: CPU: 10 PID: 0 at do_debug+0x192/0x220 [ 3272.084156] Modules linked in: fuse(E) btrfs(E) blake2b_generic(E) zstd_compress(E) zstd_decompress(E) ufs(E) ntfs(E) msdos(E) jfs(E) xfs(E) dm_mod(E) snd_seq_dummy(E) snd_hrtimer(E) snd_seq_midi(E) snd_seq_midi_event(E) snd_seq(E) nf_tables(E) nfnetlink(E) binfmt_misc(E) nls_ascii(E) nls_cp437(E) vfat(E) fat(E) snd_usb_audio(E) snd_usbmidi_lib(E) snd_rawmidi(E) eeepc_wmi(E) asus_wmi(E) snd_seq_device(E) edac_mce_amd(E) battery(E) amdgpu(E) sparse_keymap(E) video(E) r8169(E) snd_hda_codec_realtek(E) mc(E) kvm_amd(E) snd_hda_codec_hdmi(E) snd_hda_codec_generic(E) ledtrig_audio(E) kvm(E) rfkill(E) realtek(E) snd_hda_intel(E) snd_intel_dspcfg(E) libphy(E) wmi_bmof(E) snd_hda_codec(E) irqbypass(E) snd_hda_core(E) sr_mod(E) snd_hwdep(E) cdrom(E) gpu_sched(E) snd_pcm_oss(E) crct10dif_pclmul(E) crc32_pclmul(E) ttm(E) joydev(E) ghash_clmulni_intel(E) snd_mixer_oss(E) drm_kms_helper(E) snd_pcm(E) snd_timer(E) drm(E) aesni_intel(E) snd(E) crypto_simd(E) cryptd(E) sp5100_tco(E) agpgart(E) [ 3272.084199] glue_helper(E) ccp(E) i2c_algo_bit(E) sg(E) soundcore(E) i2c_piix4(E) efi_pstore(E) efivars(E) k10temp(E) rng_core(E) wmi(E) acpi_cpufreq(E) button(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) efivarfs(E) ip_tables(E) x_tables(E) autofs4(E) raid10(E) raid456(E) libcrc32c(E) async_raid6_recov(E) async_memcpy(E) async_pq(E) async_xor(E) xor(E) async_tx(E) raid6_pq(E) raid1(E) raid0(E) multipath(E) linear(E) md_mod(E) sd_mod(E) evdev(E) input_leds(E) hid_steam(E) hid_generic(E) usbhid(E) hid(E) ahci(E) xhci_pci(E) libahci(E) crc32c_intel(E) xhci_hcd(E) libata(E) usbcore(E) scsi_mod(E) gpio_amdpt(E) gpio_generic(E) [ 3272.084234] CPU: 10 PID: 0 Comm: swapper/10 Tainted: G E 5.5.13 #1 [ 3272.084235] Hardware name: System manufacturer System Product Name/TUF B450-PLUS GAMING, BIOS 2008 12/06/2019 [ 3272.084238] RIP: 0010:do_debug+0x192/0x220 [ 3272.084242] Code: 00 02 74 e0 fa 66 0f 1f 44 00 00 eb d7 e8 f6 77 0c 00 e9 bc fe ff ff e8 cc 79 0c 00 e9 2a ff ff ff f6 85 88 00 00 00 03 75 8a <0f> 0b 80 e4 bf 49 89 84 24 18 0b 00 00 f0 41 80 0c 24 10 48 81 a5 [ 3272.084243] RSP: 0018:fffffe0000223f20 EFLAGS: 00192046 [ 3272.084245] RAX: 0000000000004000 RBX: 0000000000000000 RCX: 0000000000000000 [ 3272.084246] RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffffff8205f900 [ 3272.084247] RBP: fffffe0000223f58 R08: 0000000000000000 R09: 0000000000000005 [ 3272.084248] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8887fac4cb00 [ 3272.084249] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 3272.084251] FS: 0000000000000000(0000) GS:ffff8887fea80000(0000) knlGS:0000000000000000 [ 3272.084253] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3272.084254] CR2: 00007f3a8c0f5000 CR3: 000000071e770000 CR4: 00000000003406e0 [ 3272.084255] Call Trace: [ 3272.084257] <#DB> [ 3272.084264] debug+0x28/0x60 [ 3272.084268] RIP: 0010:acpi_idle_do_entry+0x15/0x40 [ 3272.084271] Code: 66 90 fa 66 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 0f b6 47 08 3c 01 74 1f 3c 02 74 20 8b 57 04 ec <48> 8b 05 ec 07 93 00 a9 00 00 00 80 75 08 48 8b 15 4a f0 e7 00 ed [ 3272.084272] RSP: 0018:ffffc9000016fe18 EFLAGS: 495fa197 [ 3272.084274] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000068 [ 3272.084275] RDX: 0000000000000414 RSI: ffffffff820c21e0 RDI: ffff8887fa589498 [ 3272.084276] RBP: ffff8887fa589400 R08: 000002f9d6fe835d R09: 00000000000021dd [ 3272.084277] R10: 0000000000001554 R11: ffff8887feaab824 R12: ffff8887fa589498 [ 3272.084278] R13: 0000000000000002 R14: 0000000000000002 R15: ffff8887fac4cb00 [ 3272.084281] </#DB> [ 3272.084285] acpi_idle_enter+0xe8/0x2b0 [ 3272.084290] cpuidle_enter_state+0x81/0x410 [ 3272.084293] cpuidle_enter+0x29/0x40 [ 3272.084297] do_idle+0x1d7/0x260 [ 3272.084301] cpu_startup_entry+0x19/0x20 [ 3272.084304] start_secondary+0x166/0x1c0 [ 3272.084307] secondary_startup_64+0xa4/0xb0 [ 3272.084311] ---[ end trace 4f7494ff5c9ceb3d ]---
Potentially related bug #198833
Also kernel panic during booting 5.6.0-rc7+
Created attachment 288119 [details] panic during booting Image of panic
Kernel 5.5.11 seems to work better without same issues than newer kernels. 5.5.12 (and later) has changes in locking which might explain these issues.
(In reply to ilkka.prusi from comment #4) > Kernel 5.5.11 seems to work better without same issues than newer kernels. > so 5.5.11 always work well. right? > 5.5.12 (and later) has changes in locking which might explain these issues. Give that you've already narrow down the problem to 5.5.11 - 5.5.12. please run git-bisect to find out the offending commit.
(In reply to Zhang Rui from comment #5) > (In reply to ilkka.prusi from comment #4) > > Kernel 5.5.11 seems to work better without same issues than newer kernels. > > > so 5.5.11 always work well. right? > > > 5.5.12 (and later) has changes in locking which might explain these issues. > > Give that you've already narrow down the problem to 5.5.11 - 5.5.12. > please run git-bisect to find out the offending commit. Sorry I did not respond sooner, notification was lost somewhere.. "better" does not mean "no issues" - just that this particular splat was not there before: that does not really mean anything as any one of the crashes where log could not be recovered might have been the same issue. So I don't really have a known "good" configuration. Today 5.8.0-rc7 again showed similar splat but at least I could get picture of it (dmesg -w). I'll have to parse those pictures next.. Hopefully I'll get another system for comparison to rule out any hardware issues.
Looks like problem only appears when there are two identical DIMMs (of a set) on the computer but not just one of them. My guess is that RAM is incompatible in some way. Current -stable is also stable on the computer when only one of the DIMMs is installed. I did try with different components (different motherboard, power supply, different display card etc.) and those did change the issue. But it seems to be entirely hardware problem. I think this bug can be closed.