From 3c4b8f8310ad9fae3c0b36f1e871e2f9b5973550 Mon Sep 17 00:00:00 2001 From: Volker Rümelin Date: Sun, 13 Dec 2020 17:57:24 +0100 Subject: ui/gtk: limit virtual console max update interval Limit the virtual console maximum update interval to GUI_REFRESH_INTERVAL_DEFAULT. This papers over a integer overflow bug in gtk3 on Windows where the reported monitor refresh frequency can be much smaller than the real refresh frequency. The gtk bug report can be found here: https://gitlab.gnome.org/GNOME/gtk/-/issues/3394 On my Windows 10 system gtk reports a monitor refresh rate of 1.511Hz instead of 60.031Hz and slows down the screen update rate in qemu to a crawl. Provided you are affected by the gtk bug on Windows, these are the steps to reproduce the issue: Start qemu with -display gtk and activate all qemu virtual consoles and notice the reduced qemu refresh rate. Activating all virtual consoles is necessary, because gui_update() in ui/console.c uses the minimum of all display change listeners update interval and not yet activated virtual consoles report the default update interval (30ms). Signed-off-by: Volker Rümelin Message-Id: <20201213165724.13418-3-vr_qemu@t-online.de> Signed-off-by: Gerd Hoffmann --- ui/gtk.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/ui/gtk.c b/ui/gtk.c index 439c1e949f..d2004a4dc1 100644 --- a/ui/gtk.c +++ b/ui/gtk.c @@ -749,10 +749,10 @@ static void gd_resize_event(GtkGLArea *area, #endif /* - * If available, return the refresh rate of the display in milli-Hertz, - * else return 0. + * If available, return the update interval of the monitor in ms, + * else return 0 (the default update interval). */ -static int gd_refresh_rate_millihz(GtkWidget *widget) +static int gd_monitor_update_interval(GtkWidget *widget) { #ifdef GDK_VERSION_3_22 GdkWindow *win = gtk_widget_get_window(widget); @@ -760,8 +760,13 @@ static int gd_refresh_rate_millihz(GtkWidget *widget) if (win) { GdkDisplay *dpy = gtk_widget_get_display(widget); GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win); + int refresh_rate = gdk_monitor_get_refresh_rate(monitor); /* [mHz] */ - return gdk_monitor_get_refresh_rate(monitor); + if (refresh_rate) { + /* T = 1 / f = 1 [s*Hz] / f = 1000*1000 [ms*mHz] / f */ + return MIN(1000 * 1000 / refresh_rate, + GUI_REFRESH_INTERVAL_DEFAULT); + } } #endif return 0; @@ -774,7 +779,6 @@ static gboolean gd_draw_event(GtkWidget *widget, cairo_t *cr, void *opaque) int mx, my; int ww, wh; int fbw, fbh; - int refresh_rate_millihz; #if defined(CONFIG_OPENGL) if (vc->gfx.gls) { @@ -795,12 +799,8 @@ static gboolean gd_draw_event(GtkWidget *widget, cairo_t *cr, void *opaque) return FALSE; } - refresh_rate_millihz = gd_refresh_rate_millihz(vc->window ? - vc->window : s->window); - if (refresh_rate_millihz) { - /* T = 1 / f = 1 [s*Hz] / f = 1000*1000 [ms*mHz] / f */ - vc->gfx.dcl.update_interval = 1000 * 1000 / refresh_rate_millihz; - } + vc->gfx.dcl.update_interval = + gd_monitor_update_interval(vc->window ? vc->window : s->window); fbw = surface_width(vc->gfx.ds); fbh = surface_height(vc->gfx.ds); -- cgit v1.2.3-55-g7522