I loaded the vivid module with contiguous DMA and ran streaming with it with large image dimensions here are the commans: $ uname -a Linux ubuntu 5.2.0-rc5+ #1 SMP Mon Jul 1 10:17:46 PDT 2019 x86_64 x86_64 x86_64 GNU/Linux $ sudo modprobe -v vivid allocators=1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 $ v4l2-ctl -d0 --verbose -v width=2592,height=1944,pixelformat=UYVY,bytesperline=5184 --stream-mmap --stream-to video.UYVY --list-buffers Here is the warning that I got: [ 306.437224] WARNING: CPU: 1 PID: 2240 at mm/page_alloc.c:4639 __alloc_pages_nodemask+0x1f3/0x3b0 [ 306.437235] Modules linked in: rc_cec vivid v4l2_tpg videobuf2_dma_contig v4l2_dv_timings v4l2_common videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc cec rc_core crct10dif_pclmul crc32_pclmul ghash_clmulni_intel vmw_balloon aesni_intel aes_x86_64 crypto_simd cryptd glue_helper intel_rapl_perf snd_ens1371 snd_ac97_codec gameport ac97_bus snd_pcm joydev input_leds serio_raw snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd soundcore vmw_vsock_vmci_transport vsock vmw_vmci mac_hid sch_fq_codel vmwgfx ttm drm_kms_helper drm fb_sys_fops syscopyarea sysfillrect sysimgblt parport_pc ppdev lp parport ip_tables x_tables autofs4 psmouse ahci libahci e1000 mptspi mptscsih mptbase scsi_transport_spi i2c_piix4 pata_acpi [ 306.437273] CPU: 1 PID: 2240 Comm: v4l2-ctl Not tainted 5.2.0-rc5+ #1 [ 306.437275] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018 [ 306.437277] RIP: 0010:__alloc_pages_nodemask+0x1f3/0x3b0 [ 306.437280] Code: fc fe ff ff 65 48 8b 04 25 c0 6d 01 00 48 05 a0 17 00 00 41 bf 01 00 00 00 48 89 45 b0 e9 de fe ff ff 81 e7 00 20 00 00 75 02 <0f> 0b 45 31 ff eb 95 44 8b 6d c0 65 8b 05 fb fd 76 46 89 c0 48 0f [ 306.437282] RSP: 0018:ffffa42584bd39c8 EFLAGS: 00010246 [ 306.437284] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000000000 [ 306.437285] RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000000000 [ 306.437287] RBP: ffffa42584bd3a20 R08: 0000000000000000 R09: ffff9054df8072c0 [ 306.437289] R10: ffff9054cf074600 R11: 0000000000000000 R12: 0000000000000cc4 [ 306.437290] R13: ffffffffc08840d0 R14: 000000000000000c R15: 00000000ffffffff [ 306.437292] FS: 00007f842025f740(0000) GS:ffff9054dfe00000(0000) knlGS:0000000000000000 [ 306.437294] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 306.437296] CR2: 00007ffd81229000 CR3: 000000040ca28005 CR4: 00000000003606e0 [ 306.437327] Call Trace: [ 306.437338] __dma_direct_alloc_pages+0xc9/0x1c0 [ 306.437343] dma_direct_alloc_pages+0x24/0xf0 [ 306.437348] dma_direct_alloc+0xe/0x10 [ 306.437351] dma_alloc_attrs+0x84/0xd0 [ 306.437358] vb2_dc_alloc+0x79/0x110 [videobuf2_dma_contig] [ 306.437365] __vb2_queue_alloc+0x331/0x490 [videobuf2_common] [ 306.437373] vb2_core_reqbufs+0x2db/0x470 [videobuf2_common] [ 306.437376] ? __mutex_lock+0x2f5/0x930 [ 306.437385] vb2_ioctl_reqbufs+0x7e/0xb0 [videobuf2_v4l2] [ 306.437393] v4l_reqbufs+0x47/0x50 [videodev] [ 306.437400] __video_do_ioctl+0x194/0x4d0 [videodev] [ 306.437408] ? tomoyo_init_request_info+0x80/0x90 [ 306.437416] video_usercopy+0x1af/0x760 [videodev] [ 306.437422] ? v4l_s_fmt+0x6a0/0x6a0 [videodev] [ 306.437437] video_ioctl2+0x15/0x20 [videodev] [ 306.437442] v4l2_ioctl+0x49/0x50 [videodev] [ 306.437445] do_vfs_ioctl+0xa9/0x6d0 [ 306.437448] ? rcu_read_lock_sched_held+0x64/0x70 [ 306.437453] ? tomoyo_file_ioctl+0x19/0x20 [ 306.437458] ksys_ioctl+0x75/0x80 [ 306.437462] ? do_syscall_64+0x17/0x1e0 [ 306.437466] __x64_sys_ioctl+0x1a/0x20 [ 306.437469] do_syscall_64+0x65/0x1e0 [ 306.437473] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 306.437475] RIP: 0033:0x7f841f1aa5d7 [ 306.437478] Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48 [ 306.437479] RSP: 002b:00007ffd812277c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 306.437482] RAX: ffffffffffffffda RBX: 00007ffd812288e0 RCX: 00007f841f1aa5d7 [ 306.437483] RDX: 00007ffd81227830 RSI: 00000000c0145608 RDI: 0000000000000003 [ 306.437485] RBP: 00007ffd8122bd00 R08: 0000000000000000 R09: 0000562416280a46 [ 306.437486] R10: 00000000000001b6 R11: 0000000000000202 R12: 00007ffd812288e0 [ 306.437488] R13: 0000000000000002 R14: 0000000000000002 R15: 0000000000000000 [ 306.437498] irq event stamp: 15058 [ 306.437501] hardirqs last enabled at (15057): [<ffffffffb96045a7>] do_syscall_64+0x17/0x1e0 [ 306.437504] hardirqs last disabled at (15058): [<ffffffffb960384c>] trace_hardirqs_off_thunk+0x1a/0x1c [ 306.437506] softirqs last enabled at (13490): [<ffffffffba40035a>] __do_softirq+0x35a/0x409 [ 306.437509] softirqs last disabled at (13477): [<ffffffffb969eed6>] irq_exit+0xc6/0xd0 [ 306.437511] ---[ end trace 89b603670b5a81e6 ]--- [ 306.437516] vivid vivid.0: dma_alloc_coherent of size 16588800 failed
