[PATCH 3/3] drm/i915/gem: Only call eb_lookup_vma once during execbuf ioctl

[Chris Wilson]

As we no longer stash anything inside i915_vma under the exclusive
protection of struct_mutex, we do not need to revoke the i915_vma
stashes before dropping struct_mutex to handle pagefaults.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 24 +++++++------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index efec64e92a74..3578d15495e9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -792,7 +792,7 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb)
 	mutex_unlock(&eb->gem_context->mutex);
 
 	eb->args->flags |= __EXEC_VALIDATED;
-	return eb_reserve(eb);
+	return 0;
 
 err_obj:
 	i915_gem_object_put(obj);
@@ -845,14 +845,6 @@ static void eb_release_vmas(const struct i915_execbuffer *eb)
 	}
 }
 
-static void eb_reset_vmas(const struct i915_execbuffer *eb)
-{
-	eb_release_vmas(eb);
-	if (eb->lut_size > 0)
-		memset(eb->buckets, 0,
-		       sizeof(struct hlist_head) << eb->lut_size);
-}
-
 static void eb_destroy(const struct i915_execbuffer *eb)
 {
 	GEM_BUG_ON(eb->reloc_cache.rq);
@@ -1662,7 +1654,6 @@ static noinline int eb_relocate_slow(struct i915_execbuffer *eb)
 	}
 
 	/* We may process another execbuffer during the unlock... */
-	eb_reset_vmas(eb);
 	mutex_unlock(&dev->struct_mutex);
 
 	/*
@@ -1701,11 +1692,6 @@ static noinline int eb_relocate_slow(struct i915_execbuffer *eb)
 		goto out;
 	}
 
-	/* reacquire the objects */
-	err = eb_lookup_vmas(eb);
-	if (err)
-		goto err;
-
 	GEM_BUG_ON(!eb->batch);
 
 	list_for_each_entry(ev, &eb->relocs, reloc_link) {
@@ -1756,7 +1742,13 @@ static noinline int eb_relocate_slow(struct i915_execbuffer *eb)
 
 static int eb_relocate(struct i915_execbuffer *eb)
 {
-	if (eb_lookup_vmas(eb))
+	int err;
+
+	err = eb_lookup_vmas(eb);
+	if (err)
+		return err;
+
+	if (unlikely(eb_reserve(eb)))
 		goto slow;
 
 	/* The objects are in their final locations, apply the relocations. */
-- 
2.25.1