fbdev: Improve performance of sys_fillrect()

2022-03-02T19:20:34+00:00

Improve the performance of sys_fillrect() by using word-aligned 32/64-bit mov instructions. While the code tried to implement this, the compiler failed to create fast instructions. The resulting binary instructions were even slower than cfb_fillrect(), which uses the same algorithm, but operates on I/O memory. A microbenchmark measures the average number of CPU cycles for sys_fillrect() after a stabilizing period of a few minutes (i7-4790, FullHD, simpledrm, kernel with debugging). The value for CFB is given as a reference. sys_fillrect(), new: 26586 cycles sys_fillrect(), old: 166603 cycles cfb_fillrect(): 41012 cycles In the optimized case, sys_fillrect() is now ~6x faster than before and ~1.5x faster than the CFB implementation. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Reviewed-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20220223193804.18636-2-tzimmermann@suse.de

fbdev: move fbdev core files to separate directory

2014-04-17T05:10:19+00:00

Instead of having fbdev framework core files at the root fbdev directory, mixed with random fbdev device drivers, move the fbdev core files to a separate core directory. This makes it much clearer which of the files are actually part of the fbdev framework, and which are part of device drivers. Signed-off-by: Tomi Valkeinen Acked-by: Laurent Pinchart Acked-by: Geert Uytterhoeven Acked-by: Rob Clark Acked-by: Jingoo Han Acked-by: Daniel Vetter

kernel/linux.git/drivers/video/fbdev/core/sysfillrect.c, branch v6.6.132

fbdev: Improve performance of sys_fillrect()

fbdev: move fbdev core files to separate directory