This can make a significant difference for performance with some extreme
test cases such as vblank_mode=0 glxgears.
Fixes: 1e3218bc5b ("loader/dri3: Overhaul dri3_update_num_back")
Cc: "12.0 11.2" <mesa-stable@lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97549
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Always use 3 buffers when flipping. With only 2 buffers, we have to wait
for a flip to complete (which takes non-0 time even with asynchronous
flips) before we can start working on the next frame. We were previously
only using 2 buffers for flipping if the X server supports asynchronous
flips, even when we're not using asynchronous flips. This could result
in bad performance (the referenced bug report is an extreme case, where
the inter-frame stalls were preventing the GPU from reaching its maximum
clocks).
I couldn't measure any performance boost using 4 buffers with flipping.
Performance actually seemed to go down slightly, but that might have
been just noise.
Without flipping, a single back buffer is enough for swap interval 0,
but we need to use 2 back buffers when the swap interval is non-0,
otherwise we have to wait for the swap interval to pass before we can
start working on the next frame. This condition was previously reversed.
Cc: "12.0 11.2" <mesa-stable@lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97260
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Without this, the X server may accumulate stale Present event contexts
if a client ends up creating and destroying DRI drawables for the same
window.
v2: Based on Chris Wilson's review:
* Use xcb_present_select_input_checked so that protocol errors
generated by old X servers can be handled gracefully
* Use xcb_discard_reply() instead of free(xcb_request_check())
Used to support EGL_KHR_image_pixmap.
Signed-off-by: Boyan Ding <boyan.j.ding@gmail.com>
Reviewed-by: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Emil Velikov <emil.velikov@collabora.co.uk>
v2: From Martin Peres
- Try to fit in the 80-col limit as much as possible
v3: From Martin Peres
- introduce loader_dri3_helper.la to avoid dragging the xcb dep everywhere (Kristian & Emil)
- get rid of the width, height, dri_screen and is_different_gpu vfuncs (Kristian)
- replace the create/destroy functions with init/fini for dri3 drawables
- prefix static functions with dri3_ and exported ones with loader_dri3 (Emil)
- keep the function definition consistent (Emil)
Signed-off-by: Boyan Ding <boyan.j.ding@gmail.com>
Signed-off-by: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Emil Velikov <emil.velikov@collabora.co.uk>
