I was doing some testing in a KVM with a kernel based on this commit:
f69d02e37a85 (origin/master, dhowells/master, master) Merge tag 'misc-5.12-2021-03-02' of git://git.kernel.dk/linux-block
...with some ceph+fscache patches on top, and am getting a ton of warnings
popping that look like this:
[ 147.601271] ------------[ cut here ]------------
[ 147.606720] WARNING: CPU: 5 PID: 69 at drivers/gpu/drm/ttm/ttm_bo.c:139 ttm_bo_move_to_lru_tail+0x376/0x500 [ttm]
[ 147.613224] Modules linked in: nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) ip_set(E) rfkill(E) nf_tables(E) nfnetlink(E) cachefiles(E) fscache(E) netfs(E) sunrpc(E) intel_rapl_msr(E) intel_rapl_common(E) iTCO_wdt(E) intel_pmc_bxt(E) iTCO_vendor_support(E) joydev(E) virtio_balloon(E) pcspkr(E) i2c_i801(E) lpc_ich(E) i2c_smbus(E) fuse(E) zram(E) xfs(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) virtio_blk(E) virtio_console(E) ghash_clmulni_intel(E) serio_raw(E) virtio_net(E) net_failover(E) failover(E) qxl(E) drm_ttm_helper(E) ttm(E) drm_kms_helper(E) cec(E) qemu_fw_cfg(E) drm(E) [last unloaded: ip_tables]
[ 147.651585] CPU: 5 PID: 69 Comm: kworker/5:1 Tainted: G W E 5.12.0-rc1+ #62
[ 147.657667] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-1.fc33 04/01/2014
[ 147.663860] Workqueue: events qxl_gc_work [qxl]
[ 147.669451] RIP: 0010:ttm_bo_move_to_lru_tail+0x376/0x500 [ttm]
[ 147.675241] Code: ff 48 8d bd 38 01 00 00 e8 b7 cd 00 c7 48 8b 85 38 01 00 00 be ff ff ff ff 48 8d 78 70 e8 42 8a fa c7 85 c0 0f 85 d4 fc ff ff <0f> 0b e9 cd fc ff ff 48 8b 7c 24 20 e8 49 cc 00 c7 44 8b a5 f8 02
[ 147.687933] RSP: 0018:ffff888100e4fb60 EFLAGS: 00010246
[ 147.693596] RAX: 0000000000000000 RBX: ffff88812666a270 RCX: 0000000000000001
[ 147.699529] RDX: 0000000000000002 RSI: ffff88812666a1b0 RDI: ffff888100e3c418
[ 147.705425] RBP: ffff88812666a000 R08: 0000000000000000 R09: ffffffff8b7e7b4f
[ 147.711335] R10: fffffbfff16fcf69 R11: 0000000000000001 R12: ffff88812bd49000
[ 147.717216] R13: ffff88812bd4bc00 R14: ffff88812196ce90 R15: ffffffffc0561920
[ 147.723104] FS: 0000000000000000(0000) GS:ffff88841dc00000(0000) knlGS:0000000000000000
[ 147.729160] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 147.734859] CR2: 000055d11e6120b0 CR3: 000000006ba2c000 CR4: 00000000003506e0
[ 147.740764] Call Trace:
[ 147.745942] ttm_bo_release+0x78f/0x850 [ttm]
[ 147.751393] qxl_bo_unref+0x51/0x70 [qxl]
[ 147.756761] qxl_release_free_list+0xa1/0x160 [qxl]
[ 147.762287] ? qxl_get_timeline_name+0x10/0x10 [qxl]
[ 147.767856] qxl_release_free+0xbb/0x140 [qxl]
[ 147.773300] qxl_garbage_collect+0x18a/0x280 [qxl]
[ 147.778788] ? qxl_queue_garbage_collect+0xd0/0xd0 [qxl]
[ 147.784375] ? lockdep_hardirqs_on_prepare+0x178/0x220
[ 147.789931] process_one_work+0x525/0x9b0
[ 147.795314] ? pwq_dec_nr_in_flight+0x110/0x110
[ 147.800744] ? lock_acquired+0x2fe/0x560
[ 147.806137] worker_thread+0x2ea/0x6e0
[ 147.811511] ? __kthread_parkme+0xc0/0xe0
[ 147.816916] ? process_one_work+0x9b0/0x9b0
[ 147.822326] kthread+0x1fb/0x220
[ 147.827570] ? __kthread_bind_mask+0x70/0x70
[ 147.832964] ret_from_fork+0x22/0x30
[ 147.838296] irq event stamp: 194523
[ 147.843565] hardirqs last enabled at (194533): [<ffffffff87203641>] console_unlock+0x631/0x740
[ 147.849649] hardirqs last disabled at (194542): [<ffffffff8720358e>] console_unlock+0x57e/0x740
[ 147.855777] softirqs last enabled at (193620): [<ffffffff8713a38e>] __irq_exit_rcu+0x13e/0x190
[ 147.861908] softirqs last disabled at (193615): [<ffffffff8713a38e>] __irq_exit_rcu+0x13e/0x190
[ 147.868011] ---[ end trace 595bd7e9298cfe26 ]---
Is this a known bug? Is there a patch that fixes it? I'd be happy to
test it since it's making testing in VMs difficult right now.
Thanks,
--
Jeff Layton <[email protected]>