[Mesa-dev] [PATCH] llvmpipe: increase fs shader variant instruction cache limit by factor 4
brianp at vmware.com
Fri Oct 11 16:21:40 CEST 2013
On 10/11/2013 07:11 AM, sroland at vmware.com wrote:
> From: Roland Scheidegger <sroland at vmware.com>
> The previous limit of of 128*1024 was reported to cause frequent recompiles
> in some apps due to shader variant thrashing on IRC in some apps leading
> to noticeable lags.
> Note that the LP_MAX_SHADER_VARIANTS limit (1024) was more or less impossible
> to reach, since even simple fragment shaders without texturing (glxgears) used
> more than twice than 128 instructions, hence the instruction limit would have
> always been reached first (excluding things like trivial shaders not writing
> color). Even with the new limit it is VERY likely the instruction limit is hit
> Should help with such lags due to recompiles (though other shader types have
> their own limits, LP_MAX_SETUP_VARIANTS and DRAW_MAX_SHADER_VARIANTS, in
> particular the latter seems a bit small (128)).
> src/gallium/drivers/llvmpipe/lp_limits.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/src/gallium/drivers/llvmpipe/lp_limits.h b/src/gallium/drivers/llvmpipe/lp_limits.h
> index af31b35..8cfab5a 100644
> --- a/src/gallium/drivers/llvmpipe/lp_limits.h
> +++ b/src/gallium/drivers/llvmpipe/lp_limits.h
> @@ -79,7 +79,7 @@
> * Max number of instructions (for all fragment shaders combined per context)
> * that will be kept around.
> -#define LP_MAX_SHADER_INSTRUCTIONS (128*1024)
> +#define LP_MAX_SHADER_INSTRUCTIONS (512*LP_MAX_SHADER_VARIANTS)
> * Max number of setup variants that will be kept around.
Reviewed-by: Brian Paul <brianp at vmware.com>
Maybe the comment on LP_MAX_SHADER_INSTRUCTIONS should indicate that
these are LLVM IR instructions, not TGSI instructions, not machine
instructions. I had to dig for a while to find that.
More information about the mesa-dev