console: skip same-size resize

virtio-gpu does a set-scanout at each frame (it might be a driver
regression). qemu_console_resize() recreate a surface even if the size
didn't change, and this shows up in profiling reports because the
surface is cleared. With this patch, I get a +15-20% glmark2
improvement.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20160826094711.14470-1-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/ui/console.c b/ui/console.c
index 3940762851..394786b3c7 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -2101,6 +2101,13 @@ void qemu_console_resize(QemuConsole *s, int width, int height)
     DisplaySurface *surface;
 
     assert(s->console_type == GRAPHIC_CONSOLE);
+
+    if (s->surface &&
+        pixman_image_get_width(s->surface->image) == width &&
+        pixman_image_get_height(s->surface->image) == height) {
+        return;
+    }
+
     surface = qemu_create_displaysurface(width, height);
     dpy_gfx_replace_surface(s, surface);
 }