Re: [PATCH v8 00/53] Add DELETE_BUF ioctl

[Benjamin Gaignard]

Le 28/09/2023 à 15:04, Hans Verkuil a écrit :
> Hi Benjamin,
>
> On 27/09/2023 17:35, Benjamin Gaignard wrote:
> > Unlike when resolution change on keyframes, dynamic resolution change
> > on inter frames doesn't allow to do a stream off/on sequence because
> > it is need to keep all previous references alive to decode inter frames.
> > This constraint have two main problems:
> > - more memory consumption.
> > - more buffers in use.
> > To solve these issue this series introduce DELETE_BUFS ioctl and remove
> > the 32 buffers limit per queue.
> >
> > VP9 conformance tests using fluster give a score of 210/305.
> > The 24 resize inter tests (vp90-2-21-resize_inter_* files) are ok
> > but require to use postprocessor.
> >
> > Kernel branch is available here:
> > https://gitlab.collabora.com/benjamin.gaignard/for-upstream/-/commits/remove_vb2_queue_limit_v8
> >
> > GStreamer branch to use DELETE_BUF ioctl and testing dynamic resolution
> > change is here:
> > https://gitlab.freedesktop.org/benjamin.gaignard1/gstreamer/-/commits/VP9_drc
> I applied patches 1-46 on top of staging and applied patch 1/2 of v4l-utils. I chose
> 1-46 since those would be the first batch to be merged.
>
> I had to apply a small patch on top, since amphion was still using max_allowed_buffers:
>
> https://git.linuxtv.org/hverkuil/media_tree.git/commit/?h=delbuf&id=fce79aa0239a3a4e5c7634b9b7ffc356057b70b4
>
> With that change everything compiled cleanly.
>
> But running the regression tests (test-media script) failed with a kernel oops:
>
> Buffer ioctls (Input 0):
>                  fail: v4l2-test-buffers.cpp(611): q.reqbufs(node, 1)
>          test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL
> [   25.309343] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
> [   25.310067] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> [   25.310471] CPU: 0 PID: 187 Comm: v4l2-compliance Not tainted 6.6.0-rc3+ #1
> [   25.310837] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> [   25.311334] RIP: 0010:__vb2_queue_alloc+0x34c/0xd00 [videobuf2_common]
> [   25.311688] Code: 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 0c 07 00 00 49 8b b7 40 01 00 00 44 89 f0 4c 8d 2c c6 41 39 ce 73 18 4c 89 e8 48 c1 e8 03 <80> 3c 18 00 0f 85 d2 08 00 00 49 83 7d 00 00 74 02
> 0f 0b 4c 89 e8
> [   25.312670] RSP: 0018:ffff88810afef930 EFLAGS: 00010212
> [   25.312948] RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000040
> [   25.313331] RDX: ffff88810ce08814 RSI: 0000000000000000 RDI: ffff88810cfb72e0
> [   25.313708] RBP: ffff88810ce08800 R08: 0000000000001800 R09: 0000000000000001
> [   25.314097] R10: ffffffff91560b0f R11: ffffffff8f40006a R12: ffff88810afefa74
> [   25.314470] R13: 0000000000000008 R14: 0000000000000001 R15: ffff88810cfb71a0
> [   25.314854] FS:  00007fa524908440(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000
> [   25.315281] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   25.315594] CR2: 0000562855948270 CR3: 0000000109e21000 CR4: 0000000000350ef0
> [   25.315982] Call Trace:
> [   25.316122]  <TASK>
> [   25.316243]  ? die_addr+0x37/0xa0
> [   25.316433]  ? exc_general_protection+0x144/0x210
> [   25.316693]  ? asm_exc_general_protection+0x22/0x30
> [   25.316955]  ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
> [   25.317235]  ? __vb2_queue_alloc+0x34c/0xd00 [videobuf2_common]
> [   25.317555]  vb2_core_create_bufs+0x5a0/0xce0 [videobuf2_common]
> [   25.317879]  ? __vb2_queue_alloc+0xd00/0xd00 [videobuf2_common]
> [   25.318213]  vb2_create_bufs+0x680/0x7f0 [videobuf2_v4l2]
> [   25.318506]  ? __kasan_kmalloc+0x83/0x90
> [   25.318729]  ? __kmalloc+0x5c/0x150
> [   25.318924]  ? __video_do_ioctl+0x3a5/0xc20 [videodev]
> [   25.319223]  ? __copy_timestamp+0x270/0x270 [videobuf2_v4l2]
> [   25.319532]  ? v4l_sanitize_format+0x121/0x340 [videodev]
> [   25.319839]  vb2_ioctl_create_bufs+0x280/0x440 [videobuf2_v4l2]
> [   25.320162]  ? check_fmt+0x15/0x5e0 [videodev]
> [   25.320420]  v4l_create_bufs+0xa8/0x150 [videodev]
> [   25.320693]  __video_do_ioctl+0x8d0/0xc20 [videodev]
> [   25.320975]  ? v4l_prepare_buf+0xa0/0xa0 [videodev]
> [   25.321250]  ? __might_fault+0x112/0x170
> [   25.321463]  ? __might_fault+0x112/0x170
> [   25.321675]  video_usercopy+0x48c/0xd00 [videodev]
> [   25.321949]  ? v4l_prepare_buf+0xa0/0xa0 [videodev]
> [   25.322228]  ? v4l_enumstd+0x60/0x60 [videodev]
> [   25.322497]  ? selinux_bprm_creds_for_exec+0xa90/0xa90
> [   25.322779]  ? rseq_ip_fixup+0x304/0x480
> [   25.322995]  ? __up_read+0x10b/0x750
> [   25.323201]  ? rseq_get_rseq_cs+0x680/0x680
> [   25.323430]  v4l2_ioctl+0x17f/0x1f0 [videodev]
> [   25.323689]  __x64_sys_ioctl+0x127/0x190
> [   25.323905]  do_syscall_64+0x35/0x80
> [   25.324105]  entry_SYSCALL_64_after_hwframe+0x46/0xb0
> [   25.324372] RIP: 0033:0x7fa524bf44eb
> [   25.324564] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b
> 04 25 28 00 00
> [   25.325533] RSP: 002b:00007ffc888efee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> [   25.325933] RAX: ffffffffffffffda RBX: 00007ffc888f0350 RCX: 00007fa524bf44eb
> [   25.326314] RDX: 00007ffc888effb0 RSI: 00000000c100565c RDI: 0000000000000023
> [   25.326702] RBP: 00007ffc888f8550 R08: 0000000000000000 R09: 0000000000000001
> [   25.327081] R10: 0000000000000016 R11: 0000000000000246 R12: 0000000000000000
> [   25.327468] R13: 0000000000000001 R14: 00007ffc888f8010 R15: 00007ffc888f1790
> [   25.327852]  </TASK>
> [   25.327979] Modules linked in: vivid videobuf2_dma_contig v4l2_tpg v4l2_dv_timings cec videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videodev videobuf2_common mc rc_core
> [   25.328835] ---[ end trace 0000000000000000 ]---
> [   25.329083] RIP: 0010:__vb2_queue_alloc+0x34c/0xd00 [videobuf2_common]
> [   25.329434] Code: 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 0c 07 00 00 49 8b b7 40 01 00 00 44 89 f0 4c 8d 2c c6 41 39 ce 73 18 4c 89 e8 48 c1 e8 03 <80> 3c 18 00 0f 85 d2 08 00 00 49 83 7d 00 00 74 02
> 0f 0b 4c 89 e8
> [   25.330417] RSP: 0018:ffff88810afef930 EFLAGS: 00010212
> [   25.330812] RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000040
> [   25.331194] RDX: ffff88810ce08814 RSI: 0000000000000000 RDI: ffff88810cfb72e0
> [   25.331594] RBP: ffff88810ce08800 R08: 0000000000001800 R09: 0000000000000001
> [   25.331978] R10: ffffffff91560b0f R11: ffffffff8f40006a R12: ffff88810afefa74
> [   25.332360] R13: 0000000000000008 R14: 0000000000000001 R15: ffff88810cfb71a0
> [   25.332746] FS:  00007fa524908440(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000
> [   25.333170] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   25.333486] CR2: 0000562855948270 CR3: 0000000109e21000 CR4: 0000000000350ef0
> [   25.333861] Kernel panic - not syncing: Fatal exception
> [   25.334179] Kernel Offset: 0xbe00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
> [   25.334748] Rebooting in 30 seconds..
>
> I use the build scripts as described here:
>
> https://lore.kernel.org/linux-media/18989016-6392-a77b-6cf7-1223c9161def@xxxxxxxxx/
>
> I use this command to run the regression tests:
>
> ./build.sh -virtme -virtme-utils-path /usr/local/bin none delbuf
>
> (delbuf is the name of my branch)
>
> I don't really want to spend time reviewing this series until this is fixed...

Yes that make sense.
It will work on it and let you now when I had fix it.
Regards,
Benjamin

> Regards,
>
> 	Hans
>
> > changes in version 8:
> > - Add V4L2_BUF_CAP_SUPPORTS_SET_MAX_BUFS and new 'max_buffers' field in v4l2_create_buffers
> >    structure to report the maximum number of buffers that a queue could allocate.
> > - Add V4L2_BUF_CAP_SUPPORTS_DELETE_BUFS to indicate that a queue support
> >    DELETE_BUFS ioctl.
> > - Make some test drivers use more than 32 buffers and DELETE_BUFS ioctl.
> > - Fix remarks done by Hans
> > - Move "media: core: Rework how create_buf index returned value is
> >    computed" patch to the top of the serie.
> >
> > changes in version 7:
> > - Use a bitmap to know which entries are valid in queue bufs array.
> >    The number of buffers in the queue could must calculated from the
> >    bitmap so num_buffers becomes useless. This led to add quite few
> >    patches to remove it from all the drivers.
> >    Note: despiste my attention I may have miss some calls to
> >    num_buffers...
> > - Split patches to make them more readable.
> > - Run v4l2-compliance with additional delete-bufs tests.
> > - Run ./test-media -kmemleak vivid and no more failures.
> >    Note: I had to remove USERPTR streaming test because they to much
> >    frequentely hit get_framevec bug. It is not related to my series
> >    since this happens all the time on master branch.
> > - Fix Hans remarks on v6
> >
> > changes in version 6:
> > - Get a patch per driver to use vb2_get_buffer() instead of directly access
> >    to queue buffers array.
> > - Add lock in vb2_core_delete_buf()
> > - Use vb2_buffer instead of index
> > - Fix various comments
> > - Change buffer index name to BUFFER_INDEX_MASK
> > - Stop spamming kernel log with unbalanced counters
> >
> > changes in version 5:
> > - Rework offset cookie encoding pattern is n ow the first patch of the
> >    serie.
> > - Use static array instead of allocated one for postprocessor buffers.
> >
> > changes in version 4:
> > - Stop using Xarray, instead let queues decide about their own maximum
> >    number of buffer and allocate bufs array given that value.
> > - Rework offset cookie encoding pattern.
> > - Change DELETE_BUF to DELETE_BUFS because it now usable for
> >    range of buffer to be symetrical of CREATE_BUFS.
> > - Add fixes tags on couple of Verisilicon related patches.
> > - Be smarter in Verisilicon postprocessor buffers management.
> > - Rebase on top of v6.4
> >
> > changes in version 3:
> > - Use Xarray API to store allocated video buffers.
> > - No module parameter to limit the number of buffer per queue.
> > - Use Xarray inside Verisilicon driver to store postprocessor buffers
> >    and remove VB2_MAX_FRAME limit.
> > - Allow Versilicon driver to change of resolution while streaming
> > - Various fixes the Verisilicon VP9 code to improve fluster score.
> >   
> > changes in version 2:
> > - Use a dynamic array and not a list to keep trace of allocated buffers.
> >    Not use IDR interface because it is marked as deprecated in kernel
> >    documentation.
> > - Add a module parameter to limit the number of buffer per queue.
> > - Add DELETE_BUF ioctl and m2m helpers.
> >
> > Regards,
> > Benjamin
> >
> > Benjamin Gaignard (53):
> >    media: videobuf2: Rework offset 'cookie' encoding pattern
> >    media: videobuf2: Stop spamming kernel log with all queue counter
> >    media: videobuf2: Use vb2_buffer instead of index
> >    media: amphion: Use vb2_get_buffer() instead of directly access to
> >      buffers array
> >    media: mediatek: jpeg: Use vb2_get_buffer() instead of directly access
> >      to buffers array
> >    media: mediatek: vdec: Remove useless loop
> >    media: sti: hva: Use vb2_get_buffer() instead of directly access to
> >      buffers array
> >    media: visl: Use vb2_get_buffer() instead of directly access to
> >      buffers array
> >    media: atomisp: Use vb2_get_buffer() instead of directly access to
> >      buffers array
> >    media: dvb-core: Use vb2_get_buffer() instead of directly access to
> >      buffers array
> >    media: videobuf2: Access vb2_queue bufs array through helper functions
> >    media: videobuf2: Be more flexible on the number of queue stored
> >      buffers
> >    media: Report the maximum possible number of buffers for the queue
> >    media: test-drivers: vivid: Increase max supported buffers for capture
> >      queues
> >    media: test-drivers: vicodec: Increase max supported capture queue
> >      buffers
> >    media: verisilicon: Refactor postprocessor to store more buffers
> >    media: verisilicon: Store chroma and motion vectors offset
> >    media: verisilicon: g2: Use common helpers to compute chroma and mv
> >      offsets
> >    media: verisilicon: vp9: Allow to change resolution while streaming
> >    media: Remove duplicated index vs q->num_buffers check
> >    media: core: Add helper to get queue number of buffers
> >    media: dvb-core: Do not initialize twice queue num_buffer field
> >    media: dvb-frontends: rtl2832_srd: Use queue min_buffers_needed field
> >    media: video-i2c: Set min_buffers_needed to 2
> >    media: pci: cx18: Set correct value to min_buffers_needed field
> >    media: pci: dt3155: Remove useless check
> >    media: pci: netup_unidvb: Remove useless number of buffers check
> >    media: pci: tw68: Stop direct calls to queue num_buffers field
> >    media: pci: tw686x: Set min_buffers_needed to 3
> >    media: amphion: Stop direct calls to queue num_buffers field
> >    media: coda: Stop direct calls to queue num_buffers field
> >    media: mediatek: vcodec: Stop direct calls to queue num_buffers field
> >    media: nxp: Stop direct calls to queue num_buffers field
> >    media: renesas: Set min_buffers_needed to 16
> >    media: ti: Use queue min_buffers_needed field to set the min number of
> >      buffers
> >    media: verisilicon: Stop direct calls to queue num_buffers field
> >    media: test-drivers: Stop direct calls to queue num_buffers field
> >    media: usb: airspy: Set min_buffers_needed to 8
> >    media: usb: cx231xx: Set min_buffers_needed to CX231XX_MIN_BUF
> >    media: usb: hackrf: Set min_buffers_needed to 8
> >    media: usb: usbtv: Set min_buffers_needed to 2
> >    media: atomisp: Stop direct calls to queue num_buffers field
> >    media: imx: Stop direct calls to queue num_buffers field
> >    media: meson: vdec: Stop direct calls to queue num_buffers field
> >    touchscreen: sur40: Stop direct calls to queue num_buffers field
> >    sample: v4l: Stop direct calls to queue num_buffers field
> >    media: cedrus: Stop direct calls to queue num_buffers field
> >    media: core: Rework how create_buf index returned value is computed
> >    media: core: Add bitmap manage bufs array entries
> >    media: core: Free range of buffers
> >    media: v4l2: Add DELETE_BUFS ioctl
> >    media: v4l2: Add mem2mem helpers for DELETE_BUFS ioctl
> >    media: test-drivers: Use helper for DELETE_BUFS ioctl
> >
> >   .../userspace-api/media/v4l/user-func.rst     |   1 +
> >   .../media/v4l/vidioc-create-bufs.rst          |   8 +-
> >   .../media/v4l/vidioc-delete-bufs.rst          |  80 +++
> >   .../media/v4l/vidioc-reqbufs.rst              |   2 +
> >   drivers/input/touchscreen/sur40.c             |   5 +-
> >   .../media/common/videobuf2/videobuf2-core.c   | 556 +++++++++++-------
> >   .../media/common/videobuf2/videobuf2-v4l2.c   | 121 +++-
> >   drivers/media/dvb-core/dvb_vb2.c              |  17 +-
> >   drivers/media/dvb-frontends/rtl2832_sdr.c     |   9 +-
> >   drivers/media/i2c/video-i2c.c                 |   5 +-
> >   drivers/media/pci/cx18/cx18-streams.c         |  13 +-
> >   drivers/media/pci/dt3155/dt3155.c             |   2 -
> >   .../pci/netup_unidvb/netup_unidvb_core.c      |   4 +-
> >   drivers/media/pci/tw68/tw68-video.c           |   6 +-
> >   drivers/media/pci/tw686x/tw686x-video.c       |  13 +-
> >   drivers/media/platform/amphion/vpu_dbg.c      |  30 +-
> >   drivers/media/platform/amphion/vpu_v4l2.c     |   4 +-
> >   .../media/platform/chips-media/coda-common.c  |   2 +-
> >   .../platform/mediatek/jpeg/mtk_jpeg_core.c    |   7 +-
> >   .../vcodec/decoder/vdec/vdec_vp9_req_lat_if.c |   9 +-
> >   .../mediatek/vcodec/encoder/mtk_vcodec_enc.c  |   2 +-
> >   drivers/media/platform/nxp/imx7-media-csi.c   |   7 +-
> >   drivers/media/platform/renesas/rcar_drif.c    |   8 +-
> >   drivers/media/platform/st/sti/hva/hva-v4l2.c  |   9 +-
> >   .../media/platform/ti/am437x/am437x-vpfe.c    |   7 +-
> >   drivers/media/platform/ti/cal/cal-video.c     |   5 +-
> >   .../media/platform/ti/davinci/vpif_capture.c  |   5 +-
> >   .../media/platform/ti/davinci/vpif_display.c  |   5 +-
> >   drivers/media/platform/ti/omap/omap_vout.c    |   5 +-
> >   drivers/media/platform/verisilicon/hantro.h   |   9 +-
> >   .../media/platform/verisilicon/hantro_drv.c   |   5 +-
> >   .../media/platform/verisilicon/hantro_g2.c    |  14 +
> >   .../platform/verisilicon/hantro_g2_hevc_dec.c |  18 +-
> >   .../platform/verisilicon/hantro_g2_vp9_dec.c  |  28 +-
> >   .../media/platform/verisilicon/hantro_hw.h    |   7 +-
> >   .../platform/verisilicon/hantro_postproc.c    |  93 ++-
> >   .../media/platform/verisilicon/hantro_v4l2.c  |  27 +-
> >   .../media/test-drivers/vicodec/vicodec-core.c |   3 +
> >   drivers/media/test-drivers/vim2m.c            |   2 +
> >   .../media/test-drivers/vimc/vimc-capture.c    |   2 +
> >   drivers/media/test-drivers/visl/visl-dec.c    |  32 +-
> >   drivers/media/test-drivers/visl/visl-video.c  |   2 +
> >   drivers/media/test-drivers/vivid/vivid-core.c |  14 +
> >   .../media/test-drivers/vivid/vivid-meta-cap.c |   3 -
> >   .../media/test-drivers/vivid/vivid-meta-out.c |   5 +-
> >   .../test-drivers/vivid/vivid-touch-cap.c      |   5 +-
> >   .../media/test-drivers/vivid/vivid-vbi-cap.c  |   5 +-
> >   .../media/test-drivers/vivid/vivid-vbi-out.c  |   5 +-
> >   .../media/test-drivers/vivid/vivid-vid-cap.c  |   5 +-
> >   .../media/test-drivers/vivid/vivid-vid-out.c  |   5 +-
> >   drivers/media/usb/airspy/airspy.c             |   9 +-
> >   drivers/media/usb/cx231xx/cx231xx-417.c       |   4 +-
> >   drivers/media/usb/cx231xx/cx231xx-video.c     |   4 +-
> >   drivers/media/usb/hackrf/hackrf.c             |   9 +-
> >   drivers/media/usb/usbtv/usbtv-video.c         |   3 +-
> >   drivers/media/v4l2-core/v4l2-dev.c            |   1 +
> >   drivers/media/v4l2-core/v4l2-ioctl.c          |  21 +-
> >   drivers/media/v4l2-core/v4l2-mem2mem.c        |  20 +
> >   .../staging/media/atomisp/pci/atomisp_ioctl.c |   4 +-
> >   drivers/staging/media/imx/imx-media-capture.c |   7 +-
> >   drivers/staging/media/meson/vdec/vdec.c       |  13 +-
> >   .../staging/media/sunxi/cedrus/cedrus_h264.c  |   8 +-
> >   .../staging/media/sunxi/cedrus/cedrus_h265.c  |   9 +-
> >   include/media/v4l2-ioctl.h                    |   4 +
> >   include/media/v4l2-mem2mem.h                  |  12 +
> >   include/media/videobuf2-core.h                |  65 +-
> >   include/media/videobuf2-v4l2.h                |  13 +
> >   include/uapi/linux/videodev2.h                |  24 +-
> >   samples/v4l/v4l2-pci-skeleton.c               |   5 +-
> >   69 files changed, 969 insertions(+), 502 deletions(-)
> >   create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst
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