zink: create a single fence per batch on startup and then reuse

previously we would be creating a new fence per batch for every submit,
but we can just reset and reuse them if we're careful with it

based on original patch by Antonio Caggiano

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9243>

src/gallium/drivers/zink/zink_batch.c

@@ -20,11 +20,9 @@ zink_reset_batch(struct zink_context *ctx, struct zink_batch *batch)
    struct zink_screen *screen = zink_screen(ctx->base.screen);
    batch->descs_used = 0;
 
-   // cmdbuf hasn't been submitted before without a fence
-   if (batch->fence) {
+   // cmdbuf hasn't been submitted before
+   if (batch->submitted)
       zink_fence_finish(screen, batch->fence, PIPE_TIMEOUT_INFINITE);
-      zink_fence_reference(screen, &batch->fence, NULL);
-   }
 
    zink_framebuffer_reference(screen, &batch->fb, NULL);
    set_foreach(batch->programs, entry) {
@@ -69,7 +67,7 @@ zink_reset_batch(struct zink_context *ctx, struct zink_batch *batch)
 
    if (vkResetCommandPool(screen->dev, batch->cmdpool, 0) != VK_SUCCESS)
       fprintf(stderr, "vkResetCommandPool failed\n");
-   batch->has_work = false;
+   batch->submitted = batch->has_work = false;
 }
 
 void
@@ -98,10 +96,8 @@ zink_end_batch(struct zink_context *ctx, struct zink_batch *batch)
       return;
    }
 
-   assert(batch->fence == NULL);
-   batch->fence = zink_create_fence(ctx->base.screen, batch);
-   if (!batch->fence)
-      return;
+   vkResetFences(zink_screen(ctx->base.screen)->dev, 1, &batch->fence->fence);
+   zink_fence_init(batch->fence, batch);
 
    util_dynarray_foreach(&batch->persistent_resources, struct zink_resource*, res) {
        struct zink_screen *screen = zink_screen(ctx->base.screen);
@@ -134,6 +130,7 @@ zink_end_batch(struct zink_context *ctx, struct zink_batch *batch)
          ctx->reset.reset(ctx->reset.data, PIPE_GUILTY_CONTEXT_RESET);
       }
    }
+   batch->submitted = true;
 }
 
 /* returns either the compute batch id or 0 (gfx batch id) based on whether a resource

src/gallium/drivers/zink/zink_batch.h

@@ -62,6 +62,7 @@ struct zink_batch {
 
    struct set *active_queries; /* zink_query objects which were active at some point in this batch */
    bool has_work;
+   bool submitted;
    bool in_rp; //renderpass is currently active
 };
 

src/gallium/drivers/zink/zink_context.c

@@ -1393,9 +1393,8 @@ zink_wait_on_batch(struct zink_context *ctx, int batch_id)
    if (batch_id >= 0) {
       struct zink_batch *batch = batch_id == ZINK_COMPUTE_BATCH_ID ? &ctx->compute_batch : &ctx->batches[batch_id];
       if (batch != zink_curr_batch(ctx)) {
-         if (!batch->fence) { // this is the compute batch
-            zink_end_batch(ctx, batch);
-            zink_start_batch(ctx, batch);
+         if (!batch->submitted) { // this is the compute batch
+            zink_flush_compute(ctx);
          } else
             ctx->base.screen->fence_finish(ctx->base.screen, NULL, (struct pipe_fence_handle*)batch->fence,
                                        PIPE_TIMEOUT_INFINITE);
@@ -1776,6 +1775,11 @@ init_batch(struct zink_context *ctx, struct zink_batch *batch, unsigned idx)
       return false;
 
    batch->batch_id = idx;
+
+   batch->fence = zink_create_fence(ctx->base.screen, batch);
+   if (!batch->fence)
+      return false;
+
    batch->max_descs = 1500;
    return true;
 }

src/gallium/drivers/zink/zink_fence.c

@@ -58,20 +58,8 @@ zink_create_fence(struct pipe_screen *pscreen, struct zink_batch *batch)
       debug_printf("vkCreateFence failed\n");
       goto fail;
    }
-   ret->active_queries = batch->active_queries;
-   batch->active_queries = NULL;
-
    ret->batch_id = batch->batch_id;
    util_dynarray_init(&ret->resources, NULL);
-   set_foreach(batch->resources, entry) {
-      /* the fence needs its own reference to ensure it can safely access lifetime-dependent
-       * resource members
-       */
-      struct pipe_resource *r = NULL, *pres = (struct pipe_resource *)entry->key;
-      pipe_resource_reference(&r, pres);
-      util_dynarray_append(&ret->resources, struct pipe_resource*, pres);
-   }
-   ret->submitted = true;
 
    pipe_reference_init(&ret->reference, 1);
    return ret;
@@ -81,6 +69,24 @@ fail:
    return NULL;
 }
 
+void
+zink_fence_init(struct zink_fence *fence, struct zink_batch *batch)
+{
+   assert(!fence->active_queries);
+   fence->active_queries = batch->active_queries;
+   batch->active_queries = NULL;
+
+   set_foreach(batch->resources, entry) {
+      /* the fence needs its own reference to ensure it can safely access lifetime-dependent
+       * resource members
+       */
+      struct pipe_resource *r = NULL, *pres = (struct pipe_resource *)entry->key;
+      pipe_resource_reference(&r, pres);
+      util_dynarray_append(&fence->resources, struct pipe_resource*, pres);
+   }
+   fence->submitted = true;
+}
+
 void
 zink_fence_reference(struct zink_screen *screen,
                      struct zink_fence **ptr,

src/gallium/drivers/zink/zink_fence.h

@@ -47,6 +47,8 @@ zink_fence(struct pipe_fence_handle *pfence)
    return (struct zink_fence *)pfence;
 }
 
+void
+zink_fence_init(struct zink_fence *fence, struct zink_batch *batch);
 struct zink_fence *
 zink_create_fence(struct pipe_screen *pscreen, struct zink_batch *batch);