[Mesa-dev] [PATCH 3/4] radeonsi: add max waves / SIMD to shader stats (v2)

[Tom Stellard]

On Fri, Jan 22, 2016 at 03:18:12PM +0100, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> v2: account for LDS usage in PS
>     the limit is per SIMD, not per CU
> ---
>  src/gallium/drivers/radeonsi/si_shader.c | 54 +++++++++++++++++++++++++++++---
>  1 file changed, 49 insertions(+), 5 deletions(-)
> 
> diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
> index 1bd617f..33c0db6 100644
> --- a/src/gallium/drivers/radeonsi/si_shader.c
> +++ b/src/gallium/drivers/radeonsi/si_shader.c
> @@ -4001,22 +4001,65 @@ static void si_shader_dump_disassembly(const struct radeon_shader_binary *binary
>  
>  static void si_shader_dump_stats(struct si_screen *sscreen,
>  			         struct si_shader_config *conf,
> +				 unsigned num_inputs,
>  				 unsigned code_size,
>  			         struct pipe_debug_callback *debug,
>  			         unsigned processor)
>  {
> +	unsigned lds_increment = sscreen->b.chip_class >= CIK ? 512 : 256;
> +	unsigned lds_per_wave = 0;
> +	unsigned max_simd_waves = 10;
> +
> +	/* Compute LDS usage for PS. */
> +	if (processor == TGSI_PROCESSOR_FRAGMENT) {
> +		/* The minimum usage per wave is (num_inputs * 36). The maximum
> +		 * usage is (num_inputs * 36 * 16).
> +		 * We can get anything in between and it varies between waves.
> +		 *
> +		 * Other stages don't know the size at compile time or don't
> +		 * allocate LDS per wave, but instead they do it per thread group.
> +		 */
> +		lds_per_wave = conf->lds_size * lds_increment +
> +			       align(num_inputs * 36, lds_increment);
> +	}
> +
> +	/* Compute the per-SIMD wave counts. */
> +	if (conf->num_sgprs) {
> +		if (sscreen->b.chip_class >= VI)
> +			max_simd_waves = MIN2(max_simd_waves, 800 / conf->num_sgprs);
> +		else
> +			max_simd_waves = MIN2(max_simd_waves, 512 / conf->num_sgprs);
> +	}
> +
> +	if (conf->num_vgprs)
> +		max_simd_waves = MIN2(max_simd_waves, 256 / conf->num_vgprs);
> +
> +	/* LDS is 64KB per CU (4 SIMDs), divided into 16KB blocks per SIMD
> +	 * that PS can use.
> +	 */
> +	if (lds_per_wave)
> +		max_simd_waves = MIN2(max_simd_waves, 16384 / lds_per_wave);
> +
>  	if (r600_can_dump_shader(&sscreen->b, processor)) {
>  		fprintf(stderr, "*** SHADER STATS ***\n"
> -			"SGPRS: %d\nVGPRS: %d\nCode Size: %d bytes\nLDS: %d blocks\n"
> -			"Scratch: %d bytes per wave\n********************\n",
> +			"SGPRS: %d\n"
> +			"VGPRS: %d\n"
> +			"Code Size: %d bytes\n"
> +			"LDS: %d blocks\n"
> +			"Scratch: %d bytes per wave\n"
> +			"Max Waves: %d\n"
> +			"********************\n",
>  			conf->num_sgprs, conf->num_vgprs, code_size,
> -			conf->lds_size, conf->scratch_bytes_per_wave);
> +			conf->lds_size, conf->scratch_bytes_per_wave,
> +			max_simd_waves);
>  	}
>  
>  	pipe_debug_message(debug, SHADER_INFO,
> -			   "Shader Stats: SGPRS: %d VGPRS: %d Code Size: %d LDS: %d Scratch: %d",
> +			   "Shader Stats: SGPRS: %d VGPRS: %d Code Size: %d "
> +			   "LDS: %d Scratch: %d Max Waves: %d",
>  			   conf->num_sgprs, conf->num_vgprs, code_size,
> -			   conf->lds_size, conf->scratch_bytes_per_wave);
> +			   conf->lds_size, conf->scratch_bytes_per_wave,
> +			   max_simd_waves);
>  }
>  
>  void si_shader_dump(struct si_screen *sscreen, struct si_shader *shader,
> @@ -4027,6 +4070,7 @@ void si_shader_dump(struct si_screen *sscreen, struct si_shader *shader,
>  			si_shader_dump_disassembly(&shader->binary, debug);
>  
>  	si_shader_dump_stats(sscreen, &shader->config,
> +                            shader->selector->info.num_inputs,

clover is segfaulting here, because shader->selector is NULL for compute
shaders.

-Tom

>  			     shader->binary.code_size, debug, processor);
>  }
>  
> -- 
> 2.1.4
> 
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