nvc0: reduce overhead from always marking buffers dirty

We would revalidate buffers when anything was touched at all. Which is
unfortunate, since the state tracker does not use CSO's to reduce the
workload. So instead implement a protocol to ensure that something has
changed before revalidating all the SSBOs.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "12.0" <mesa-stable@lists.freedesktop.org>

diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_state.c b/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
index e437a6479a008eea829d7983cea2e169bbcd83f3..6cdc007a08664fe087061bdd39dbe99620c6327c 100644 (file)
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
@@ -1287,29 +1287,41 @@ nvc0_set_shader_images(struct pipe_context *pipe, unsigned shader,
       nvc0_context(pipe)->dirty_3d |= NVC0_NEW_3D_SURFACES;
 }
 
-static void
+static bool
 nvc0_bind_buffers_range(struct nvc0_context *nvc0, const unsigned t,
                          unsigned start, unsigned nr,
                          struct pipe_shader_buffer *pbuffers)
 {
    const unsigned end = start + nr;
-   const unsigned mask = ((1 << nr) - 1) << start;
+   unsigned mask = 0;
    unsigned i;
 
    assert(t < 6);
 
    if (pbuffers) {
       for (i = start; i < end; ++i) {
+         struct pipe_shader_buffer *buf = &nvc0->buffers[t][i];
          const unsigned p = i - start;
+         if (buf->buffer == pbuffers[p].buffer &&
+             buf->buffer_offset == pbuffers[p].buffer_offset &&
+             buf->buffer_size == pbuffers[p].buffer_size)
+            continue;
+
+         mask |= (1 << i);
          if (pbuffers[p].buffer)
             nvc0->buffers_valid[t] |= (1 << i);
          else
             nvc0->buffers_valid[t] &= ~(1 << i);
-         nvc0->buffers[t][i].buffer_offset = pbuffers[p].buffer_offset;
-         nvc0->buffers[t][i].buffer_size = pbuffers[p].buffer_size;
-         pipe_resource_reference(&nvc0->buffers[t][i].buffer, pbuffers[p].buffer);
+         buf->buffer_offset = pbuffers[p].buffer_offset;
+         buf->buffer_size = pbuffers[p].buffer_size;
+         pipe_resource_reference(&buf->buffer, pbuffers[p].buffer);
       }
+      if (!mask)
+         return false;
    } else {
+      mask = ((1 << nr) - 1) << start;
+      if (!(nvc0->buffers_valid[t] & mask))
+         return false;
       for (i = start; i < end; ++i)
          pipe_resource_reference(&nvc0->buffers[t][i].buffer, NULL);
       nvc0->buffers_valid[t] &= ~mask;
@@ -1321,6 +1333,7 @@ nvc0_bind_buffers_range(struct nvc0_context *nvc0, const unsigned t,
    else
       nouveau_bufctx_reset(nvc0->bufctx_3d, NVC0_BIND_3D_BUF);
 
+   return true;
 }
 
 static void
@@ -1330,7 +1343,8 @@ nvc0_set_shader_buffers(struct pipe_context *pipe,
                         struct pipe_shader_buffer *buffers)
 {
    const unsigned s = nvc0_shader_stage(shader);
-   nvc0_bind_buffers_range(nvc0_context(pipe), s, start, nr, buffers);
+   if (!nvc0_bind_buffers_range(nvc0_context(pipe), s, start, nr, buffers))
+      return;
 
    if (s == 5)
       nvc0_context(pipe)->dirty_cp |= NVC0_NEW_CP_BUFFERS;