Hi, Jens, Jens Axboe <axboe@xxxxxxxxx> writes: > You can also find the patches in my aio-poll branch: > > http://git.kernel.dk/cgit/linux-block/log/?h=aio-poll > > or by cloning: > > git://git.kernel.dk/linux-block aio-poll I made an xfs file system on a partition of an nvme device. I created a 1 GB file on that file system, and then ran the test program you provided. It immediately spewed the following: [ 139.533754] BUG: Bad page state in process aio-ring pfn:5f394f2 [ 139.539763] page:ffffde6a3ce53c80 count:-38 mapcount:1 mapping:0000000000000000 index:0x1 [ 139.547942] flags: 0x57ffffc0000000() [ 139.551607] raw: 0057ffffc0000000 dead000000000100 dead000000000200 0000000000000000 [ 139.559346] raw: 0000000000000001 0000000000000000 ffffffda00000000 0000000000000000 [ 139.567085] page dumped because: nonzero _refcount [ 139.571876] Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc devlink ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc dm_mirror dm_region_hash dm_log dm_mod intel_rapl skx_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm irqbypass vfat fat ipmi_ssif crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate intel_uncore intel_rapl_perf iTCO_wdt iTCO_vendor_support ipmi_si mei_me pcspkr ipmi_devintf dax_pmem sg i2c_i801 lpc_ich mei device_dax ipmi_msghandler ioatdma wmi acpi_pad acpi_power_meter dca ip_tables xfs libcrc32c nd_pmem nd_btt sd_mod sr_mod cdrom ast i2c_algo_bit drm_kms_helper syscopyarea crc32c_intel sysfillrect sysimgblt i40e fb_sys_fops ttm drm nvme ahci nvme_core libahci libata nfit libnvdimm [ 139.649936] CPU: 46 PID: 13137 Comm: aio-ring Not tainted 4.20.0-rc5+ #1 [ 139.656635] Hardware name: Intel Corporation ... [ 139.667062] Call Trace: [ 139.669522] dump_stack+0x46/0x5b [ 139.672845] bad_page+0xf5/0x10f [ 139.676080] free_pcppages_bulk+0x588/0x5d0 [ 139.680271] free_unref_page_list+0xfc/0x170 [ 139.684545] release_pages+0x103/0x4a0 [ 139.688293] __pagevec_release+0x2b/0x30 [ 139.692223] invalidate_inode_pages2_range+0x3ea/0x560 [ 139.697360] ? pagevec_lookup_range_tag+0x24/0x30 [ 139.702068] ? __filemap_fdatawait_range+0x87/0x150 [ 139.706951] iomap_dio_rw+0x1de/0x3b0 [ 139.710622] ? current_time+0x4f/0x90 [ 139.714288] ? atime_needs_update+0x6c/0xd0 [ 139.718474] ? down_read+0xe/0x30 [ 139.721821] xfs_file_dio_aio_read+0x65/0xe0 [xfs] [ 139.726633] xfs_file_read_iter+0xba/0xd0 [xfs] [ 139.731172] aio_read+0x13e/0x1b0 [ 139.734499] ? iomap_dio_complete+0x98/0x150 [ 139.738778] ? put_aio_ring_file.isra.26+0x70/0x70 [ 139.743568] ? iomap_dio_complete_work+0x17/0x30 [ 139.748188] ? iomap_dio_bio_end_io+0x160/0x180 [ 139.752720] ? kmem_cache_alloc+0x170/0x1c0 [ 139.756907] __io_submit_one+0x3e0/0xa10 [ 139.760832] aio_ring_submit+0xcf/0x1a0 [ 139.764675] ? do_page_fault+0x2d/0x120 [ 139.768512] ? aio_iopoll_getevents+0x1cf/0x220 [ 139.773042] __x64_sys_io_ring_enter+0xf8/0x160 [ 139.777578] do_syscall_64+0x55/0x1a0 [ 139.781243] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 139.786294] RIP: 0033:0x7f3ea04511c9 [ 139.789873] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 dc 2c 00 f7 d8 64 89 01 48 [ 139.808620] RSP: 002b:00007f3ea0357e28 EFLAGS: 00000246 ORIG_RAX: 0000000000000150 [ 139.816185] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f3ea04511c9 [ 139.823317] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00007f3ea0d63000 [ 139.830448] RBP: 0000000000000000 R08: 0000000300000000 R09: 0000000300000000 [ 139.837581] R10: 0000000000000003 R11: 0000000000000246 R12: 00000000025ea080 [ 139.844714] R13: 00000000025ea000 R14: 0000000000602120 R15: 0000000000000001 [ 139.851848] Disabling lock debugging due to kernel taint Followed by this: [ 163.724474] watchdog: BUG: soft lockup - CPU#46 stuck for 22s! [aio-ring:13137] [ 163.731786] Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc devlink ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc dm_mirror dm_region_hash dm_log dm_mod intel_rapl skx_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm irqbypass vfat fat ipmi_ssif crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate intel_uncore intel_rapl_perf iTCO_wdt iTCO_vendor_support ipmi_si mei_me pcspkr ipmi_devintf dax_pmem sg i2c_i801 lpc_ich mei device_dax ipmi_msghandler ioatdma wmi acpi_pad acpi_power_meter dca ip_tables xfs libcrc32c nd_pmem nd_btt sd_mod sr_mod cdrom ast i2c_algo_bit drm_kms_helper syscopyarea crc32c_intel sysfillrect sysimgblt i40e fb_sys_fops ttm drm nvme ahci nvme_core libahci libata nfit libnvdimm [ 163.809847] CPU: 46 PID: 13137 Comm: aio-ring Tainted: G B 4.20.0-rc5+ #1 [ 163.817931] Hardware name: Intel Corporation ... [ 163.828358] RIP: 0010:nvme_poll+0x7/0x1d0 [nvme] [ 163.832975] Code: 4c 89 d7 e8 2b cb f8 d1 49 89 c2 e9 4d ff ff ff 8b 73 24 e9 77 ff ff ff 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 <41> 56 41 55 41 54 55 53 48 8b 9f c8 00 00 00 0f b7 43 78 0f b6 53 [ 163.851718] RSP: 0018:ffffa89d4872bdc0 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 [ 163.859287] RAX: ffffffffc0479640 RBX: ffff8f03f85d9e00 RCX: 00000000ffffffff [ 163.866420] RDX: ffff8f03f50fec00 RSI: 00000000000f0210 RDI: ffff8f52f790d800 [ 163.873550] RBP: 0000000000000001 R08: 00000000ffffffff R09: ffff8f52f1f0a580 [ 163.880682] R10: 0000000000000200 R11: 0000000000000001 R12: 0000000000000000 [ 163.887817] R13: ffff8f03f85d9e00 R14: ffff8f03e8bb5ee0 R15: ffff8f52f790d800 [ 163.894948] FS: 00007f3ea0358700(0000) GS:ffff8f52ff580000(0000) knlGS:0000000000000000 [ 163.903035] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 163.908779] CR2: 00007f3ea0d63000 CR3: 0000005f2a070006 CR4: 00000000007606e0 [ 163.915913] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 163.923044] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 163.930178] PKRU: 55555554 [ 163.932888] Call Trace: [ 163.935347] blk_poll+0x268/0x360 [ 163.938678] aio_iopoll_getevents+0x174/0x220 [ 163.943037] __aio_iopoll_check+0x4a/0x70 [ 163.947053] __x64_sys_io_ring_enter+0x121/0x160 [ 163.951673] do_syscall_64+0x55/0x1a0 [ 163.955350] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 163.960405] RIP: 0033:0x7f3ea04511c9 [ 163.963985] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 dc 2c 00 f7 d8 64 89 01 48 [ 163.982728] RSP: 002b:00007f3ea0357e28 EFLAGS: 00000246 ORIG_RAX: 0000000000000150 [ 163.990298] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f3ea04511c9 [ 163.997429] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00007f3ea0d63000 [ 164.004562] RBP: 0000000000000001 R08: 0000000300000000 R09: 0000000300000000 [ 164.011693] R10: 0000000000000003 R11: 0000000000000246 R12: 00000000025ea040 [ 164.018828] R13: 00000000025ea000 R14: 0000000000602120 R15: 0000000000000001 and the process is unkillable and eating ~100% cpu. Let me know if you need any more info. -Jeff