Re: [Qemu-devel] [PATCH 2/2] optimize screendump for the common non-switch case

[Alon Levy]

On Thu, Feb 23, 2012 at 10:22:38AM +0100, Gerd Hoffmann wrote:
> switch console only if needed, also pass down whenever the console was
> switched or not because a displaysurface redraw is only needed in case
> the console was switched.
> 

You've missed some implementations of the vga_hw_screen_dump_ptr, see

$ git grep -A3 graphic_console_init | grep screen | grep -v -w screen_dump
hw/blizzard.c-                                 blizzard_screen_dump, NULL, s);
hw/g364fb.c-                                 g364fb_screen_dump, NULL, s);
hw/jazz_led.c-                                 jazz_led_screen_dump,
hw/omap_dss.c-                                    omap_invalidate_display, 
omap_screen_dump, s);
hw/omap_lcdc.c-                                    omap_screen_dump, NULL, s);
hw/pxa2xx_lcd.c-                                 pxa2xx_screen_dump, NULL, s);
hw/qxl.c-                                   qxl_hw_screen_dump, 
qxl_hw_text_update, qxl);
hw/tcx.c-                                     tcx24_screen_dump, NULL, s);
hw/tcx.c-                                     tcx_screen_dump, NULL, s);
hw/vmware_vga.c-                                     vmsvga_screen_dump,

> Signed-off-by: Gerd Hoffmann <address@hidden>
> ---
>  console.c       |   10 +++++++---
>  console.h       |    2 +-
>  hw/qxl.c        |    4 ++--
>  hw/vga.c        |   10 ++++++----
>  hw/vmware_vga.c |    4 ++--
>  5 files changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/console.c b/console.c
> index 135394f..b3bd14a 100644
> --- a/console.c
> +++ b/console.c
> @@ -176,17 +176,21 @@ void vga_hw_invalidate(void)
>  void vga_hw_screen_dump(const char *filename)
>  {
>      TextConsole *previous_active_console;
> +    bool cswitch;
>  
>      previous_active_console = active_console;
> +    cswitch = previous_active_console && previous_active_console->index != 0;
>  
>      /* There is currently no way of specifying which screen we want to dump,
>         so always dump the first one.  */
> -    console_select(0);
> +    if (cswitch) {
> +        console_select(0);
> +    }
>      if (consoles[0] && consoles[0]->hw_screen_dump) {
> -        consoles[0]->hw_screen_dump(consoles[0]->hw, filename);
> +        consoles[0]->hw_screen_dump(consoles[0]->hw, filename, cswitch);
>      }
>  
> -    if (previous_active_console) {
> +    if (cswitch) {
>          console_select(previous_active_console->index);
>      }
>  }
> diff --git a/console.h b/console.h
> index 6ba0d5d..1fc8ea3 100644
> --- a/console.h
> +++ b/console.h
> @@ -340,7 +340,7 @@ static inline void console_write_ch(console_ch_t *dest, 
> uint32_t ch)
>  
>  typedef void (*vga_hw_update_ptr)(void *);
>  typedef void (*vga_hw_invalidate_ptr)(void *);
> -typedef void (*vga_hw_screen_dump_ptr)(void *, const char *);
> +typedef void (*vga_hw_screen_dump_ptr)(void *, const char *, bool cswitch);
>  typedef void (*vga_hw_text_update_ptr)(void *, console_ch_t *);
>  
>  DisplayState *graphic_console_init(vga_hw_update_ptr update,
> diff --git a/hw/qxl.c b/hw/qxl.c
> index e38bb29..f4c68ab 100644
> --- a/hw/qxl.c
> +++ b/hw/qxl.c
> @@ -1438,7 +1438,7 @@ static void qxl_hw_invalidate(void *opaque)
>      vga->invalidate(vga);
>  }
>  
> -static void qxl_hw_screen_dump(void *opaque, const char *filename)
> +static void qxl_hw_screen_dump(void *opaque, const char *filename, bool 
> cswitch)
>  {
>      PCIQXLDevice *qxl = opaque;
>      VGACommonState *vga = &qxl->vga;
> @@ -1450,7 +1450,7 @@ static void qxl_hw_screen_dump(void *opaque, const char 
> *filename)
>          ppm_save(filename, qxl->ssd.ds->surface);
>          break;
>      case QXL_MODE_VGA:
> -        vga->screen_dump(vga, filename);
> +        vga->screen_dump(vga, filename, cswitch);
>          break;
>      default:
>          break;
> diff --git a/hw/vga.c b/hw/vga.c
> index f8f30f8..5994f43 100644
> --- a/hw/vga.c
> +++ b/hw/vga.c
> @@ -162,7 +162,7 @@ static uint32_t expand4[256];
>  static uint16_t expand2[256];
>  static uint8_t expand4to8[16];
>  
> -static void vga_screen_dump(void *opaque, const char *filename);
> +static void vga_screen_dump(void *opaque, const char *filename, bool 
> cswitch);
>  
>  static void vga_update_memory_access(VGACommonState *s)
>  {
> @@ -2407,11 +2407,13 @@ int ppm_save(const char *filename, struct 
> DisplaySurface *ds)
>  
>  /* save the vga display in a PPM image even if no display is
>     available */
> -static void vga_screen_dump(void *opaque, const char *filename)
> +static void vga_screen_dump(void *opaque, const char *filename, bool cswitch)
>  {
>      VGACommonState *s = opaque;
>  
> -    vga_invalidate_display(s);
> -    vga_hw_update();
> +    if (cswitch) {
> +        vga_invalidate_display(s);
> +        vga_hw_update();
> +    }
>      ppm_save(filename, s->ds->surface);
>  }
> diff --git a/hw/vmware_vga.c b/hw/vmware_vga.c
> index f8afa3c..142d9f4 100644
> --- a/hw/vmware_vga.c
> +++ b/hw/vmware_vga.c
> @@ -1003,11 +1003,11 @@ static void vmsvga_invalidate_display(void *opaque)
>  
>  /* save the vga display in a PPM image even if no display is
>     available */
> -static void vmsvga_screen_dump(void *opaque, const char *filename)
> +static void vmsvga_screen_dump(void *opaque, const char *filename, bool 
> cswitch)
>  {
>      struct vmsvga_state_s *s = opaque;
>      if (!s->enable) {
> -        s->vga.screen_dump(&s->vga, filename);
> +        s->vga.screen_dump(&s->vga, filename, cswitch);
>          return;
>      }
>  
> -- 
> 1.7.1
>