On 11/6/25 14:49, Dmitry Osipenko wrote: > On 10/31/25 08:04, Kasireddy, Vivek wrote: >> Hi Dmitry, >> >>> Subject: Re: [PATCH v4] drm/virtgpu: Make vblank event dependent on the >>> external sync >>> >>> On 10/29/25 08:47, Kasireddy, Vivek wrote: >>>> I applied this patch and tested 3 different scenarios: >>>> 1) blob=true + imported buffers >>>> root@localhost:weston_upstream/weston# ./build/clients/weston-simple- >>> egl -o & >>>> Using config: r8g8b8a0 >>>> has EGL_EXT_buffer_age and EGL_EXT_swap_buffers_with_damage >>>> has EGL_EXT_surface_compression >>>> 245 frames in 5 seconds: 49.000000 fps >>>> 236 frames in 5 seconds: 47.200001 fps >>>> 279 frames in 5 seconds: 55.799999 fps >>>> 240 frames in 5 seconds: 48.000000 fps >>>> 244 frames in 5 seconds: 48.799999 fps >>>> 283 frames in 5 seconds: 56.599998 fps >>>> 274 frames in 5 seconds: 54.799999 fps >>>> >>>> 2) blob=true >>>> root@localhost:/weston_upstream/weston# ./build/clients/weston-simple- >>> egl -o & >>>> Using config: r8g8b8a0 >>>> has EGL_EXT_buffer_age and EGL_EXT_swap_buffers_with_damage >>>> has EGL_EXT_surface_compression >>>> 167 frames in 5 seconds: 33.400002 fps >>>> 208 frames in 5 seconds: 41.599998 fps >>>> 203 frames in 5 seconds: 40.599998 fps >>>> 252 frames in 5 seconds: 50.400002 fps >>>> 180 frames in 5 seconds: 36.000000 fps >>>> 219 frames in 5 seconds: 43.799999 fps >>>> 176 frames in 5 seconds: 35.200001 fps >>>> 220 frames in 5 seconds: 44.000000 fps >>> >>> Thanks for the testing. >>> >>> For the second scenario I'm getting better result, it's 55-60fps for me. >>> Given that this is a SW rendering, curious whether that's because you're >>> testing on a lower end machine(?) >> I am testing with a dGPU (B60) on the Host where I am running Gnome Xorg >> but I am running Gnome Wayland in the Guest. What compositors are you >> running on the Host and Guest? Kwin? Also, could you please share your >> Qemu launch parameters as well so that we can try to figure out the reason >> for the performance discrepancy? > > Did further testing on older IvyBridge machine and getting comparable > result to yours on it. > > I'm using exactly same QEMU setup as you do with nothing special in the > cmdline. Tested with both KDE and Gnome on host. > > On IvyBridge getting: > > - 46-55fps jittery with GTK display + blob + vblank_timer > - 46-55fps jittery with GTK display + blob + vblank_timer + > vblank_mode=1 to disable vsync on host > - constant 60fps with GTK display without blob + vblank_timer > - constant 60fps with GTK display + blob without vblank_timer > - constant 60fps with SDL display + blob + vblank_timer > > So, discrepancy of the results is directly tied to CPU performance + GTK > oddity when SW+blob rendering is used on guest. > > Why SDL performs much better than GTK I don't know. >
Forgot to mention that I'm testing using my [1] QEMU branch. [1] https://gitlab.freedesktop.org/digetx/qemu/-/commits/native-context-v14 -- Best regards, Dmitry
