[Mesa-dev] [PATCH] swr: Rework scratch space allocation

[Cherniak, Bruce]

Reviewed-by: Bruce Cherniak <bruce.cherniak at intel.com> 

> On Oct 19, 2017, at 4:40 PM, George Kyriazis <george.kyriazis at intel.com> wrote:
> 
> Remove allocation of > 2kbyte buffers into context memory in
> swr_copy_to_scatch_space() (which is used to copy small vertex/index buffers
> and shader constants to a scratch space to be used by the upcoming draw.)
> 
> Large shader constant allocations need to be done in the circular scratch
> buffer instead of context memory, because their values persist across
> render calls.
> 
> Also lower SCRATCH_SINGLE_ALLOCATION_LIMIT to 8k, since allocations of larger
> buffers will get too large for the circular scratch space.
> 
> Fixes render issues with CEI Ensight.
> ---
> src/gallium/drivers/swr/swr_scratch.cpp | 51 ++++++++++++++-------------------
> src/gallium/drivers/swr/swr_screen.cpp  |  2 +-
> 2 files changed, 23 insertions(+), 30 deletions(-)
> 
> diff --git a/src/gallium/drivers/swr/swr_scratch.cpp b/src/gallium/drivers/swr/swr_scratch.cpp
> index d298a48..c31f3c2 100644
> --- a/src/gallium/drivers/swr/swr_scratch.cpp
> +++ b/src/gallium/drivers/swr/swr_scratch.cpp
> @@ -28,8 +28,6 @@
> #include "swr_fence_work.h"
> #include "api.h"
> 
> -#define SCRATCH_SINGLE_ALLOCATION_LIMIT 2048
> -
> void *
> swr_copy_to_scratch_space(struct swr_context *ctx,
>                           struct swr_scratch_space *space,
> @@ -40,41 +38,36 @@ swr_copy_to_scratch_space(struct swr_context *ctx,
>    assert(space);
>    assert(size);
> 
> -   if (size >= SCRATCH_SINGLE_ALLOCATION_LIMIT) {
> -      /* Use per draw SwrAllocDrawContextMemory for larger copies */
> -      ptr = ctx->api.pfnSwrAllocDrawContextMemory(ctx->swrContext, size, 4);
> -   } else {
> -      /* Allocate enough so that MAX_DRAWS_IN_FLIGHT sets fit. */
> -      unsigned int max_size_in_flight = size * KNOB_MAX_DRAWS_IN_FLIGHT;
> -
> -      /* Need to grow space */
> -      if (max_size_in_flight > space->current_size) {
> -         space->current_size = max_size_in_flight;
> +   /* Allocate enough so that MAX_DRAWS_IN_FLIGHT sets fit. */
> +   unsigned int max_size_in_flight = size * KNOB_MAX_DRAWS_IN_FLIGHT;
> 
> -         if (space->base) {
> -            /* defer delete, use aligned-free */
> -            struct swr_screen *screen = swr_screen(ctx->pipe.screen);
> -            swr_fence_work_free(screen->flush_fence, space->base, true);
> -            space->base = NULL;
> -         }
> +   /* Need to grow space */
> +   if (max_size_in_flight > space->current_size) {
> +      space->current_size = max_size_in_flight;
> 
> -         if (!space->base) {
> -            space->base = (uint8_t *)AlignedMalloc(space->current_size, 
> -                                                   sizeof(void *));
> -            space->head = (void *)space->base;
> -         }
> +      if (space->base) {
> +         /* defer delete, use aligned-free */
> +         struct swr_screen *screen = swr_screen(ctx->pipe.screen);
> +         swr_fence_work_free(screen->flush_fence, space->base, true);
> +         space->base = NULL;
>       }
> 
> -      /* Wrap */
> -      if (((uint8_t *)space->head + size)
> -          >= ((uint8_t *)space->base + space->current_size)) {
> -         space->head = space->base;
> +      if (!space->base) {
> +         space->base = (uint8_t *)AlignedMalloc(space->current_size, 
> +                                                sizeof(void *));
> +         space->head = (void *)space->base;
>       }
> +   }
> 
> -      ptr = space->head;
> -      space->head = (uint8_t *)space->head + size;
> +   /* Wrap */
> +   if (((uint8_t *)space->head + size)
> +       >= ((uint8_t *)space->base + space->current_size)) {
> +      space->head = space->base;
>    }
> 
> +   ptr = space->head;
> +   space->head = (uint8_t *)space->head + size;
> +
>    /* Copy user_buffer to scratch */
>    if (user_buffer)
>       memcpy(ptr, user_buffer, size);
> diff --git a/src/gallium/drivers/swr/swr_screen.cpp b/src/gallium/drivers/swr/swr_screen.cpp
> index 46b3a00..b21c35e 100644
> --- a/src/gallium/drivers/swr/swr_screen.cpp
> +++ b/src/gallium/drivers/swr/swr_screen.cpp
> @@ -57,7 +57,7 @@
> #define SWR_MAX_TEXTURE_ARRAY_LAYERS 512 /* 8K x 512 / 8K x 8K x 512 */
> 
> /* Default max client_copy_limit */
> -#define SWR_CLIENT_COPY_LIMIT 32768
> +#define SWR_CLIENT_COPY_LIMIT 8192
> 
> /* Flag indicates creation of alternate surface, to prevent recursive loop
>  * in resource creation when msaa_force_enable is set. */
> -- 
> 2.7.4
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev