[0/2] fbdev: Improve performance of fbdev console

Message

Thomas Zimmermann Feb. 17, 2022, 10:34 a.m. UTC

Optimize performance of the fbdev console for the common case of
software-based clearing and image blitting.

The commit descripton of each patch contains resuls os a simple
microbenchmark. I also tested the full patchset's effect on the
console output by printing directory listings (i7-4790, FullHD,
simpledrm, kernel with debugging).

  > time find /usr/share/doc -type f

In the unoptimized case:

  real    0m6.173s
  user    0m0.044s
  sys     0m6.107s

With optimizations applied:

  real    0m4.754s
  user    0m0.044s
  sys     0m4.698s

In the optimized case, printing the directory listing is ~25% faster
than before.

Thomas Zimmermann (2):
  fbdev: Improve performance of sys_fillrect()
  fbdev: Improve performance of sys_imageblit()

 drivers/video/fbdev/core/sysfillrect.c | 16 ++------
 drivers/video/fbdev/core/sysimgblt.c   | 51 ++++++++++++++++++++------
 2 files changed, 42 insertions(+), 25 deletions(-)