From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Thomas Huth To: slof@lists.ozlabs.org, nikunj@linux.vnet.ibm.com, aik@ozlabs.ru Cc: gkurz@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org Subject: [SLOF PATCH 0/2] fbuffer: Improve the speed of the cursor drawing Date: Tue, 28 Jul 2015 12:19:53 +0200 Message-Id: <1438078795-14360-1-git-send-email-thuth@redhat.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Greg Kurz recently already did a great work by introducing the invert-region helpers to speed up the drawing of the cursor. This made the grub2 command prompt and editor mode usable. However, the editor mode of grub2 is still sluggish - because grub2 always redraws the whole line (with cursor enabled!) when you enter a character, and since cursor and character drawing is still not super-fast in SLOF, this sums up to a noticable delay. So I tried to speed up the drawing a little bit and came up with the following patches. I've used a little "benchmark" in Forth to see how the patches improve the drawing: 1 buffer: etest-buf : etest erase-screen 41 etest-buf c! 1b emit 5b emit [char] H emit cursor-on milliseconds 20 0 do 3a 0 do etest-buf 1 terminal-write drop loop cr loop milliseconds swap - ." Duration: " .d ." ms" cr ; Without my patches, the etest function takes 1.8 s to draw. With the first patch applied, the function take ca. 1.2 s. With both patches applied, the function only takes ca. 0.8 s ! The first patch changes invert-region to use a bigger access width if possible. And the second patch simply decreases the size of the cursor from a full-character size rectangle to an underscore-like cursor instead... not sure whether this is acceptable, but at least I think it looks as good as the original cursor. Apart from my patches, I think grub2 should also disable the cursor when redrawing a whole line in the editor. However, I do not have much clue about the grub2 sources yet ... is anybody familiar with this and could give some pointers? Thomas Huth (2): fbuffer: Improve invert-region helper fbuffer: Use a smaller cursor board-js2x/slof/helper.fs | 13 ++++++++----- board-qemu/slof/helper.fs | 14 ++++++++++---- slof/fs/fbuffer.fs | 5 +++-- 3 files changed, 21 insertions(+), 11 deletions(-) -- 1.8.3.1