sched_ext: warning

[Schlaefer]

Okt 08 18:50:44 dt kernel: ------------[ cut here ]------------
Okt 08 18:50:44 dt kernel: WARNING: CPU: 2 PID: 1 at kernel/sched/ext.c:3832 scx_cgroup_can_attach+0x121/0x270
Okt 08 18:50:44 dt kernel: Modules linked in: nf_conntrack_netlink nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nfnetlink_acct wireguard udp_diag l>
Okt 08 18:50:44 dt kernel:  snd_compress btbcm btintel snd_hda_intel btrtl x86_pkg_temp_thermal snd_intel_dspcfg btmtk intel_powerclamp snd_intel>
Okt 08 18:50:44 dt kernel:  crct10dif_pclmul crc32_pclmul polyval_clmulni polyval_generic ghash_clmulni_intel sha512_ssse3 drm_buddy sha256_ssse3>
Okt 08 18:50:44 dt kernel: CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G           OE      6.11.2-5-cachyos #1 7b3314db03b851bb3e066ab89dae212287>
Okt 08 18:50:44 dt kernel: Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Okt 08 18:50:44 dt kernel: Hardware name: Gigabyte Technology Co., Ltd. B560M AORUS PRO AX/B560M AORUS PRO AX, BIOS F14 12/19/2023
Okt 08 18:50:44 dt kernel: Sched_ext: bpfland (enabled+all), task: runnable_at=+0ms
Okt 08 18:50:44 dt kernel: RIP: 0010:scx_cgroup_can_attach+0x121/0x270
Okt 08 18:50:44 dt kernel: Code: 8b 04 24 48 8b 10 4c 89 ff 4c 89 e6 41 ff d3 0f 1f 00 85 c0 74 83 eb 1e 90 48 c7 c0 80 c8 8d 9c 49 83 bf a8 03 0>
Okt 08 18:50:44 dt kernel: RSP: 0018:ffffbe3dc0067980 EFLAGS: 00010286
Okt 08 18:50:44 dt kernel: RAX: ffff97d58a7e0000 RBX: ffffbe3dc0067a30 RCX: ffff97d5888d1e00
Okt 08 18:50:44 dt kernel: RDX: ffff97d5a0d6f800 RSI: ffffbe3dc0067980 RDI: 0000000000000001
Okt 08 18:50:44 dt kernel: RBP: 0000000000000000 R08: ffff97d5ebd44610 R09: ffff97d5ebd444a0
Okt 08 18:50:44 dt kernel: R10: ffff97d59a46c090 R11: ffffffff9a92fea0 R12: ffffffff9c8dc880
Okt 08 18:50:44 dt kernel: R13: ffffbe3dc0067a10 R14: ffffbe3dc0067980 R15: ffff97d5802d8000
Okt 08 18:50:44 dt kernel: FS:  00007f18a8039880(0000) GS:ffff97dd1f900000(0000) knlGS:0000000000000000
Okt 08 18:50:44 dt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Okt 08 18:50:44 dt kernel: CR2: 000063dcae67d010 CR3: 000000010d92e001 CR4: 0000000000770ef0
Okt 08 18:50:44 dt kernel: PKRU: 55555554
Okt 08 18:50:44 dt kernel: Call Trace:
Okt 08 18:50:44 dt kernel:  <TASK>
Okt 08 18:50:44 dt kernel:  ? __warn+0xd0/0x1c0
Okt 08 18:50:44 dt kernel:  ? scx_cgroup_can_attach+0x121/0x270
Okt 08 18:50:44 dt kernel:  ? report_bug+0x144/0x1f0
Okt 08 18:50:44 dt kernel:  ? handle_bug+0x42/0x70
Okt 08 18:50:44 dt kernel:  ? exc_invalid_op+0x1a/0x50
Okt 08 18:50:44 dt kernel:  ? asm_exc_invalid_op+0x1a/0x20
Okt 08 18:50:44 dt kernel:  ? __pfx_cpu_cgroup_can_attach+0x10/0x10
Okt 08 18:50:44 dt kernel:  ? scx_cgroup_can_attach+0x121/0x270
Okt 08 18:50:44 dt kernel:  cgroup_migrate_execute+0xa1/0x3c0
Okt 08 18:50:44 dt kernel:  ? cgroup_migrate_prepare_dst+0x53/0x320
Okt 08 18:50:44 dt kernel:  cgroup_apply_control+0x524/0x570
Okt 08 18:50:44 dt kernel:  cgroup_subtree_control_write+0x4a0/0x570
Okt 08 18:50:44 dt kernel:  kernfs_fop_write_iter.llvm.16101920100708754+0xfd/0x180
Okt 08 18:50:44 dt kernel:  vfs_write+0x350/0x400
Okt 08 18:50:44 dt kernel:  __x64_sys_write+0x79/0xe0
Okt 08 18:50:44 dt kernel:  do_syscall_64+0x88/0x170
Okt 08 18:50:44 dt kernel:  ? __d_lookup+0x118/0x130
Okt 08 18:50:44 dt kernel:  ? generic_fillattr+0x49/0x110
Okt 08 18:50:44 dt kernel:  ? kernfs_iop_getattr+0xcc/0xe0
Okt 08 18:50:44 dt kernel:  ? __se_sys_newfstat+0x267/0x2b0
Okt 08 18:50:44 dt kernel:  ? syscall_exit_to_user_mode+0x97/0xc0
Okt 08 18:50:44 dt kernel:  ? do_syscall_64+0x94/0x170
Okt 08 18:50:44 dt kernel:  ? do_user_addr_fault+0x289/0x740
Okt 08 18:50:44 dt kernel:  entry_SYSCALL_64_after_hwframe+0x76/0x7e
Okt 08 18:50:44 dt kernel: RIP: 0033:0x7f18a7724be4
Okt 08 18:50:44 dt kernel: Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d c5 94 0d 00 00 74 13 b8 01 0>
Okt 08 18:50:44 dt kernel: RSP: 002b:00007ffffb73a9c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
Okt 08 18:50:44 dt kernel: RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f18a7724be4
Okt 08 18:50:44 dt kernel: RDX: 0000000000000005 RSI: 000063dcae9106f0 RDI: 000000000000004f
Okt 08 18:50:44 dt kernel: RBP: 000063dcae9106f0 R08: 0000000000000000 R09: 0000000000000000
Okt 08 18:50:44 dt kernel: R10: 000000000000000d R11: 0000000000000202 R12: 0000000000000005
Okt 08 18:50:44 dt kernel: R13: 000063dcae6fe8a0 R14: 00007f18a77f5010 R15: 00007f18a77f4ec0
Okt 08 18:50:44 dt kernel:  </TASK>
Okt 08 18:50:44 dt kernel: ---[ end trace 0000000000000000 ]---

• Processors: 12 × 11th Gen Intel® Core™ i5-11400 @ 2.60GHz
• cachyos-v4/linux-cachyos 6.11.2-5
• cachyos-v4/scx-scheds-git 1.0.5.r43.ga673dcf-1
• Happened immediately after SDDM login to start into plasma-wayland session
• Not reproducible
• First crash warning/error I've seen using sched_ext for months now

[htejun]

Yeah, I know this happens but couldn't reproduce it myself. For all the current schedulers, this is a harmless WARN. If you find a repro, please share. Thanks.

[sirlucjan]

Yes, I had the same issue.

paź 11 13:07:21 cachyos kernel: RIP: 0010:scx_cgroup_can_attach+0x121/0x270
paź 11 13:07:21 cachyos kernel: Code: a8 b8 02 4c 89 ff 4c 89 e6 48 8b 10 41 ff d3 0f 1f 00 85 c0 74 83 eb 1e 90 48 c7 c0 40 fe 8d 90 49 83 bf a8 03 00 00 00 74 c7 <0f> 0b 49 39 c4 75 c5 e9 6e ff ff ff 89 c5 48 89 e6 48 89 df e8 d6
paź 11 13:07:21 cachyos kernel: RSP: 0018:ffffa563400a3b90 EFLAGS: 00010286
paź 11 13:07:21 cachyos kernel: RAX: ffffffff908dfe40 RBX: ffffa563400a3c40 RCX: ffffffff912e4380
paź 11 13:07:21 cachyos kernel: RDX: ffff91056e62d800 RSI: ffffa563400a3b90 RDI: 0000000000000001
paź 11 13:07:21 cachyos kernel: RBP: 0000000000000000 R08: ffff91059bdf5610 R09: ffff91059bdf54a0
paź 11 13:07:21 cachyos kernel: R10: ffff91059bdf2ca0 R11: ffffffff8e732ff0 R12: ffffffff908dfe40
paź 11 13:07:21 cachyos kernel: R13: ffffa563400a3c20 R14: ffffa563400a3b90 R15: ffff91050081cbc0
paź 11 13:07:21 cachyos kernel: FS:  00007ba09abb7880(0000) GS:ffff910c1e680000(0000) knlGS:0000000000000000
paź 11 13:07:21 cachyos kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
paź 11 13:07:21 cachyos kernel: CR2: 0000797238cdbb40 CR3: 0000000100f2c000 CR4: 0000000000f50ef0
paź 11 13:07:21 cachyos kernel: PKRU: 55555554
paź 11 13:07:21 cachyos kernel: Call Trace:
paź 11 13:07:21 cachyos kernel:  <TASK>
paź 11 13:07:21 cachyos kernel:  ? __warn+0xd5/0x1d0
paź 11 13:07:21 cachyos kernel:  ? scx_cgroup_can_attach+0x121/0x270
paź 11 13:07:21 cachyos kernel:  ? report_bug+0x141/0x1e0
paź 11 13:07:21 cachyos kernel:  ? handle_bug+0x6a/0x90
paź 11 13:07:21 cachyos kernel:  ? exc_invalid_op+0x1a/0x50
paź 11 13:07:21 cachyos kernel:  ? asm_exc_invalid_op+0x1a/0x20
paź 11 13:07:21 cachyos kernel:  ? __pfx_cpu_cgroup_can_attach+0x10/0x10
paź 11 13:07:21 cachyos kernel:  ? scx_cgroup_can_attach+0x121/0x270
paź 11 13:07:21 cachyos kernel:  cgroup_migrate_execute+0xa1/0x3c0
paź 11 13:07:21 cachyos kernel:  ? cgroup_migrate_prepare_dst+0x53/0x320
paź 11 13:07:21 cachyos kernel:  cgroup_apply_control+0x514/0x560
paź 11 13:07:21 cachyos kernel:  cgroup_subtree_control_write+0x4a0/0x570
paź 11 13:07:21 cachyos kernel:  kernfs_fop_write_iter.llvm.10549860284947137359+0xfa/0x180
paź 11 13:07:21 cachyos kernel:  vfs_write+0x342/0x3f0
paź 11 13:07:21 cachyos kernel:  __x64_sys_write+0x79/0xe0
paź 11 13:07:21 cachyos kernel:  do_syscall_64+0x88/0x170
paź 11 13:07:21 cachyos kernel:  ? srso_alias_return_thunk+0x5/0xfbef5
paź 11 13:07:21 cachyos kernel:  ? __se_sys_name_to_handle_at+0x15a/0x240
paź 11 13:07:21 cachyos kernel:  ? srso_alias_return_thunk+0x5/0xfbef5
paź 11 13:07:21 cachyos kernel:  ? syscall_exit_to_user_mode+0x97/0xc0
paź 11 13:07:21 cachyos kernel:  ? srso_alias_return_thunk+0x5/0xfbef5
paź 11 13:07:21 cachyos kernel:  ? do_syscall_64+0x94/0x170
paź 11 13:07:21 cachyos kernel:  ? srso_alias_return_thunk+0x5/0xfbef5
paź 11 13:07:21 cachyos kernel:  ? do_syscall_64+0x94/0x170
paź 11 13:07:21 cachyos kernel:  ? srso_alias_return_thunk+0x5/0xfbef5
paź 11 13:07:21 cachyos kernel:  ? srso_alias_return_thunk+0x5/0xfbef5
paź 11 13:07:21 cachyos kernel:  entry_SYSCALL_64_after_hwframe+0x76/0x7e
paź 11 13:07:21 cachyos kernel: RIP: 0033:0x7ba09ad24ca4
paź 11 13:07:21 cachyos kernel: Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 05 94 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 53 48 83 ec 20 48 89 54 24 18
paź 11 13:07:21 cachyos kernel: RSP: 002b:00007fff8de6b3a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
paź 11 13:07:21 cachyos kernel: RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007ba09ad24ca4
paź 11 13:07:21 cachyos kernel: RDX: 0000000000000008 RSI: 00005ce42f501bc0 RDI: 000000000000001e
paź 11 13:07:21 cachyos kernel: RBP: 00005ce42f501bc0 R08: 0000000000000000 R09: 0000000000001000
paź 11 13:07:21 cachyos kernel: R10: 00005ce42f501bb0 R11: 0000000000000202 R12: 0000000000000008
paź 11 13:07:21 cachyos kernel: R13: 00005ce42f22abb0 R14: 00007ba09adf5010 R15: 00007ba09adf4ec0
paź 11 13:07:21 cachyos kernel:  </TASK>
paź 11 13:07:21 cachyos kernel: ---[ end trace 0000000000000000 ]---