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* [PATCH] kvm tools, ui: Optimize SDL updates
@ 2011-06-03 21:20 Pekka Enberg
  2011-06-04  9:54 ` Ingo Molnar
  0 siblings, 1 reply; 19+ messages in thread
From: Pekka Enberg @ 2011-06-03 21:20 UTC (permalink / raw)
  To: kvm; +Cc: Pekka Enberg, Cyrill Gorcunov, Ingo Molnar, John Floren,
	Sasha Levin

This patch optimizes SDL updates by keeping track of which parts of the guest
screen have been written since last update and calling SDL_BlitSurface() and
SDL_UpdateRect() for only changed parts of the screen.

Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Floren <john@jfloren.net>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
---
 tools/kvm/ui/sdl.c |   60 +++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/tools/kvm/ui/sdl.c b/tools/kvm/ui/sdl.c
index bc69ed9..f175a60 100644
--- a/tools/kvm/ui/sdl.c
+++ b/tools/kvm/ui/sdl.c
@@ -6,11 +6,51 @@
 #include <SDL/SDL.h>
 #include <pthread.h>
 
+#include <linux/kernel.h>
+
 #define FRAME_RATE		25
 
+static u64 min_x;
+static u64 min_y;
+static u64 max_x;
+static u64 max_y;
+
+static void sdl__finish(void)
+{
+	max_x = 0;
+	max_y = 0;
+	min_x = ULLONG_MAX;
+	min_y = ULLONG_MAX;
+}
+
+static inline bool sdl__need_update(void)
+{
+	return min_x < max_x && min_y < max_y;
+}
+
 static void sdl__write(struct framebuffer *fb, u64 addr, u8 *data, u32 len)
 {
-	memcpy(&fb->mem[addr - fb->mem_addr], data, len);
+	u64 x, y;
+	u64 pos;
+
+	pos = addr - fb->mem_addr;
+
+	x = (pos / 4) % fb->width;
+	y = ((pos / 4) - x) / fb->width;
+
+	if (x < min_x)
+		min_x = x;
+
+	if (y < min_y)
+		min_y = y;
+
+	if (x > max_x)
+		max_x = x;
+
+	if (y > max_y)
+		max_y = y;
+
+	memcpy(&fb->mem[pos], data, len);
 }
 
 static void *sdl__thread(void *p)
@@ -40,9 +80,23 @@ static void *sdl__thread(void *p)
 	if (!screen)
 		die("Unable to set SDL video mode");
 
+	sdl__finish();
+
 	for (;;) {
-		SDL_BlitSurface(guest_screen, NULL, screen, NULL);
-		SDL_UpdateRect(screen, 0, 0, 0, 0);
+		if (sdl__need_update()) {
+			SDL_Rect rect = {
+				.x		= min_x,
+				.y		= min_y,
+				.w		= max_x - min_x,
+				.h		= max_y - min_y,
+			};
+
+			SDL_BlitSurface(guest_screen, &rect, screen, &rect);
+			SDL_UpdateRect(screen, rect.x, rect.y, rect.w, rect.h);
+		}
+
+		sdl__finish();
+
 		while (SDL_PollEvent(&ev)) {
 			switch (ev.type) {
 			case SDL_QUIT:
-- 
1.7.0.4


^ permalink raw reply related	[flat|nested] 19+ messages in thread
end of thread, other threads:[~2011-06-06  7:03 UTC | newest]

Thread overview: 19+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-06-03 21:20 [PATCH] kvm tools, ui: Optimize SDL updates Pekka Enberg
2011-06-04  9:54 ` Ingo Molnar
2011-06-04 10:27   ` Alexander Graf
2011-06-04 10:42     ` Ingo Molnar
2011-06-04 10:46       ` Alexander Graf
2011-06-04 10:54         ` Ingo Molnar
2011-06-04 11:07           ` Alexander Graf
2011-06-04 11:53             ` Ingo Molnar
2011-06-04 11:59               ` Alexander Graf
2011-06-04 12:04               ` Sasha Levin
2011-06-04 13:48                 ` Alexander Graf
2011-06-04 14:19                   ` Sasha Levin
2011-06-04 15:21                     ` Alexander Graf
2011-06-04 15:34                       ` Sasha Levin
2011-06-04 15:40                         ` Alexander Graf
2011-06-04 16:49                           ` Sasha Levin
2011-06-05  8:41                             ` Alexander Graf
2011-06-05  9:32             ` Alon Levy
2011-06-06  7:02             ` Gerd Hoffmann

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