[Mesa-dev] [PATCH 4/9] intel: batch-decoder: don't asks for constant BO until decoding

[Lionel Landwerlin]

With PPGTT mappings, our aubinator implementation can be quite slow if
we request a buffer that doesn't exist. Instead of doing a PPGTT walk
for invalid addresses (0 lengths), wait until we're sure we want to
decode the data.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
 src/intel/common/gen_batch_decoder.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/intel/common/gen_batch_decoder.c b/src/intel/common/gen_batch_decoder.c
index 2b6978da92d..81d8298c28b 100644
--- a/src/intel/common/gen_batch_decoder.c
+++ b/src/intel/common/gen_batch_decoder.c
@@ -562,9 +562,8 @@ decode_3dstate_constant(struct gen_batch_decode_ctx *ctx, const uint32_t *p)
    struct gen_group *body =
       gen_spec_find_struct(ctx->spec, "3DSTATE_CONSTANT_BODY");
 
-   uint32_t read_length[4];
-   struct gen_batch_decode_bo buffer[4];
-   memset(buffer, 0, sizeof(buffer));
+   uint32_t read_length[4] = {0};
+   uint64_t read_addr[4];
 
    struct gen_field_iterator outer;
    gen_field_iterator_init(&outer, inst, p, 0, false);
@@ -581,18 +580,24 @@ decode_3dstate_constant(struct gen_batch_decode_ctx *ctx, const uint32_t *p)
          if (sscanf(iter.name, "Read Length[%d]", &idx) == 1) {
             read_length[idx] = iter.raw_value;
          } else if (sscanf(iter.name, "Buffer[%d]", &idx) == 1) {
-            buffer[idx] = ctx_get_bo(ctx, iter.raw_value);
+            read_addr[idx] = iter.raw_value;
          }
       }
 
       for (int i = 0; i < 4; i++) {
-         if (read_length[i] == 0 || buffer[i].map == NULL)
+         if (read_length[i] == 0)
             continue;
 
+         struct gen_batch_decode_bo buffer = ctx_get_bo(ctx, read_addr[i]);
+         if (!buffer.map) {
+            fprintf(ctx->fp, "constant buffer %d unavailable\n", i);
+            continue;
+         }
+
          unsigned size = read_length[i] * 32;
          fprintf(ctx->fp, "constant buffer %d, size %u\n", i, size);
 
-         ctx_print_buffer(ctx, buffer[i], size, 0, -1);
+         ctx_print_buffer(ctx, buffer, size, 0, -1);
       }
    }
 }
-- 
2.17.1