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| author | Thomas Zimmermann <tzimmermann@suse.de> | 2022-02-23 20:38:04 +0100 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2022-03-02 20:26:02 +0100 |
| commit | 9ae2ac4d31a85ce59cc560d514a31b95f4ace154 (patch) | |
| tree | a11406e9e6d448237a69c6c55a628db0394dce62 /Documentation/gpu/todo.rst | |
| parent | fbdev: Improve performance of cfb_imageblit() (diff) | |
| download | linux-9ae2ac4d31a85ce59cc560d514a31b95f4ace154.tar.xz linux-9ae2ac4d31a85ce59cc560d514a31b95f4ace154.zip | |
drm: Add TODO item for optimizing format helpers
Add a TODO item for optimizing blitting and format-conversion helpers
in DRM and fbdev. There's always demand for faster graphics output.
v4:
* fix typos (Sam)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223193804.18636-6-tzimmermann@suse.de
Diffstat (limited to 'Documentation/gpu/todo.rst')
| -rw-r--r-- | Documentation/gpu/todo.rst | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index d6a7ebf717be..4260c62d751b 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -241,6 +241,28 @@ Contact: Thomas Zimmermann <tzimmermann@suse.de>, Daniel Vetter Level: Advanced +Benchmark and optimize blitting and format-conversion function +-------------------------------------------------------------- + +Drawing to dispay memory quickly is crucial for many applications' +performance. + +On at least x86-64, sys_imageblit() is significantly slower than +cfb_imageblit(), even though both use the same blitting algorithm and +the latter is written for I/O memory. It turns out that cfb_imageblit() +uses movl instructions, while sys_imageblit apparently does not. This +seems to be a problem with gcc's optimizer. DRM's format-conversion +helpers might be subject to similar issues. + +Benchmark and optimize fbdev's sys_() helpers and DRM's format-conversion +helpers. In cases that can be further optimized, maybe implement a different +algorithm. For micro-optimizations, use movl/movq instructions explicitly. +That might possibly require architecture-specific helpers (e.g., storel() +storeq()). + +Contact: Thomas Zimmermann <tzimmermann@suse.de> + +Level: Intermediate drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup ----------------------------------------------------------------- |