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Opened 4 years ago

Closed 4 years ago

Last modified 17 months ago

#1825 closed task (fixed)

multi window nvfbc

Reported by: Antoine Martin Owned by: Antoine Martin
Priority: major Milestone: 2.3
Component: encodings Version: 2.2.x
Keywords: Cc:


Split from ticket:1801#comment:5.

It should be possible to use a single nvfbc capture instance for multiple monitors and just adjust the buffer offsets.

Change History (6)

comment:1 Changed 4 years ago by Antoine Martin

Status: newassigned

Basic support added in r19137.

Still TODO:

  • capture only once for all monitors
  • handle suspend + resume without closing capture
  • fix segfault when we make the buffer copy narrower (smaller dst_pitch) - waste of GPU RAM, but not a huge problem since we don't copy more than we need
  • keep track of cuda buffers we allocate and prevent memory overcommit somehow - re-use buffers?
  • when shutting down, free the buffer so we don't try to use it after the cuda context is destroyed
  • support multi-window mode in the "sys" backend
  • nvenc is not used in some cases? (dual 4k too large for nvenc if dimension is miscalculated: individual windows can be encoded at 4k)
Last edited 4 years ago by Antoine Martin (previous) (diff)

comment:2 Changed 4 years ago by Antoine Martin

Resolution: fixed
Status: assignedclosed


  • r19138: capture only once for all monitors
  • r19145: use correct image wrapper dimensions: fixes crash when copying also fixes nvenc not being used, keep track of image wrappers to avoid using cuda context after we clean it up
  • r19146: narrower buffer copy
  • r19147: "sys" backend support

comment:3 Changed 4 years ago by Antoine Martin

Detected a memory leak during testing for #1823.
Only occurs with nvfbc CUDA buffers and nvenc.
Downloading to system memory before re-uploading to a CUDA buffer with XPRA_NVENC_GPU_MEMCOPY=0 (introduced in r19151) does not help.
Using a non-nvfbc source for video does not leak either.

r19153 fixes this but I'm not 100% sure why that is. The image wrapper method was being called before this change, just maybe not from the right thread or not with the correct CUDA context.

comment:4 Changed 4 years ago by Antoine Martin

  • r19160: correct fix for the GPU memory leak
  • r19157: don't call damage if nvfbc tells us the pixels have not changed
  • r19159: better cuda cleanup
Last edited 4 years ago by Antoine Martin (previous) (diff)

comment:5 Changed 4 years ago by Antoine Martin

The shadow pointer shown on the client may be at the wrong location in 2.3, this is fixed in 2.4: r19603.

comment:6 Changed 17 months ago by migration script

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1825

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