[Mesa-dev] [PATCH] radeonsi: don't use fast color clear for small images even on APUs

[Konstantin Kharlamov]

I'm wondering, how is r600g different in that regard? I tried wiring up the code into evergreen_do_fast_color_clear(), both in this state and by using 256*256 — however FPS for me always varies around the same 1420.

That said, I'm seeing lots of CPU used by Xorg, glxgears, and compton — I'm wondering if CPU cap could be the reason?

В письме от среда, 13 декабря 2017 г. 2:53:12 MSK пользователь Marek Olšák написал:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> Increase the limit and handle non-square images better.
> 
> This makes glxgears 20% faster on APUs, and a little more on dGPUs.
> We all use and love glxgears.
> ---
>  src/gallium/drivers/radeonsi/si_clear.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/src/gallium/drivers/radeonsi/si_clear.c b/src/gallium/drivers/radeonsi/si_clear.c
> index 0ac83f4..464b9d7 100644
> --- a/src/gallium/drivers/radeonsi/si_clear.c
> +++ b/src/gallium/drivers/radeonsi/si_clear.c
> @@ -418,26 +418,25 @@ static void si_do_fast_color_clear(struct si_context *sctx,
>  			    sctx->b.family == CHIP_STONEY)
>  				tex->num_slow_clears++;
>  		}
>  
>  		bool need_decompress_pass = false;
>  
>  		/* Use a slow clear for small surfaces where the cost of
>  		 * the eliminate pass can be higher than the benefit of fast
>  		 * clear. The closed driver does this, but the numbers may differ.
>  		 *
> -		 * Always use fast clear on APUs.
> +		 * This helps on both dGPUs and APUs, even small APUs like Mullins.
>  		 */
> -		bool too_small = sctx->screen->info.has_dedicated_vram &&
> -				 tex->resource.b.b.nr_samples <= 1 &&
> -				 tex->resource.b.b.width0 <= 256 &&
> -				 tex->resource.b.b.height0 <= 256;
> +		bool too_small = tex->resource.b.b.nr_samples <= 1 &&
> +				 tex->resource.b.b.width0 *
> +				 tex->resource.b.b.height0 <= 512 * 512;
>  
>  		/* Try to clear DCC first, otherwise try CMASK. */
>  		if (vi_dcc_enabled(tex, 0)) {
>  			uint32_t reset_value;
>  			bool clear_words_needed;
>  
>  			if (sctx->screen->debug_flags & DBG(NO_DCC_CLEAR))
>  				continue;
>  
>  			/* This can only occur with MSAA. */
>