benchmarks/gem_blt: Fixup a couple of non-llc foibles

When extending the batch for multiple copies, we need to remember to
flag it as being in the CPU write domain so that the new values get
flushed out to main memory before execution. We also have to be careful
not to specify NO_RELOC for the extended batch as the execobjects will
have been updated but we write the wrong presumed offsets. Subsequent
iterations will be correct and we can tell the kernel then to skip the
relocations entirely.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 11 insertions, 10 deletions

diff --git a/benchmarks/gem_blt.c b/benchmarks/gem_blt.c
index 02373612..8fe80bc1 100644
--- a/benchmarks/gem_blt.c
+++ b/benchmarks/gem_blt.c
@@ -166,7 +166,7 @@ static int run(int object, int batch, int count, int set, int reps)
 	struct drm_i915_gem_exec_object2 exec[3];
 	struct drm_i915_gem_relocation_entry *reloc;
 	uint32_t *buf, handle, src, dst;
-	int fd, len, gen, size;
+	int fd, len, gen, size, nreloc;
 	int ring;
 
 	size = ALIGN(batch * 64, 4096);
@@ -183,17 +183,18 @@ static int run(int object, int batch, int count, int set, int reps)
 	dst = gem_create(fd, object);
 
 	len = gem_linear_blt(fd, buf, 0, 0, 1, object, reloc);
+	if (has_64bit_reloc)
+		nreloc = len > 56 ? 4 : 2;
+	else
+		nreloc = len > 40 ? 4 : 2;
 
 	memset(exec, 0, sizeof(exec));
 	exec[0].handle = src;
 	exec[1].handle = dst;
 
 	exec[2].handle = handle;
-	if (has_64bit_reloc)
-		exec[2].relocation_count = len > 56 ? 4 : 2;
-	else
-		exec[2].relocation_count = len > 40 ? 4 : 2;
 	exec[2].relocs_ptr = (uintptr_t)reloc;
+	exec[2].relocation_count = nreloc;
 
 	ring = 0;
 	if (gen >= 6)
@@ -205,7 +206,6 @@ static int run(int object, int batch, int count, int set, int reps)
 	execbuf.batch_len = len;
 	execbuf.flags = ring;
 	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
-	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
 
 	if (__gem_execbuf(fd, &execbuf)) {
 		gem_set_domain(fd, handle, I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
@@ -217,24 +217,25 @@ static int run(int object, int batch, int count, int set, int reps)
 	gem_sync(fd, handle);
 
 	if (batch > 1) {
-		int nreloc = exec[2].relocation_count;
-
 		if (execbuf.flags & LOCAL_I915_EXEC_HANDLE_LUT) {
 			src = 0;
 			dst = 1;
 		}
 
+		gem_set_domain(fd, handle, I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
 		for (int i = 1; i < batch; i++) {
 			len = gem_linear_blt(fd, buf, len - 8,
 					     src, dst, object,
-					     reloc + exec[2].relocation_count);
-			exec[2].relocation_count += nreloc;
+					     reloc + nreloc * i);
 		}
+		exec[2].relocation_count = nreloc * batch;
 		execbuf.batch_len = len;
 
 		gem_execbuf(fd, &execbuf);
 		gem_sync(fd, handle);
 	}
+	if (execbuf.flags & LOCAL_I915_EXEC_HANDLE_LUT)
+		execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
 
 	while (reps--) {
 		double min = HUGE_VAL;