[Intel-gfx] [PATCH 13/16] drm/i915: Simplify eb_lookup_vmas()
Chris Wilson
chris at chris-wilson.co.uk
Wed Jul 26 13:26:07 UTC 2017
Since the introduction of being able to perform a lockless lookup of an
object (i915_gem_object_get_rcu() in fbbd37b36fa5 ("drm/i915: Move object
release to a freelist + worker") we no longer need to split the
object/vma lookup into 3 phases and so combine them into a much simpler
single loop.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 122 +++++++++--------------------
1 file changed, 36 insertions(+), 86 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 92d88ec271c1..ed906093fb63 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -450,7 +450,9 @@ eb_validate_vma(struct i915_execbuffer *eb,
}
static int
-eb_add_vma(struct i915_execbuffer *eb, unsigned int i, struct i915_vma *vma)
+eb_add_vma(struct i915_execbuffer *eb,
+ unsigned int i, struct i915_vma *vma,
+ unsigned int flags)
{
struct drm_i915_gem_exec_object2 *entry = &eb->exec[i];
int err;
@@ -480,7 +482,7 @@ eb_add_vma(struct i915_execbuffer *eb, unsigned int i, struct i915_vma *vma)
* to find the right target VMA when doing relocations.
*/
eb->vma[i] = vma;
- eb->flags[i] = entry->flags;
+ eb->flags[i] = entry->flags | flags;
vma->exec_flags = &eb->flags[i];
err = 0;
@@ -687,13 +689,9 @@ static int eb_select_context(struct i915_execbuffer *eb)
static int eb_lookup_vmas(struct i915_execbuffer *eb)
{
-#define INTERMEDIATE BIT(0)
- const unsigned int count = eb->buffer_count;
struct i915_gem_context_vma_lut *lut = &eb->ctx->vma_lut;
- struct i915_vma *vma;
- struct idr *idr;
+ struct drm_i915_gem_object *uninitialized_var(obj);
unsigned int i;
- int slow_pass = -1;
int err;
if (unlikely(i915_gem_context_is_closed(eb->ctx)))
@@ -709,82 +707,38 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb)
flush_work(&lut->resize);
GEM_BUG_ON(lut->ht_size & I915_CTX_RESIZE_IN_PROGRESS);
- for (i = 0; i < count; i++) {
- hlist_for_each_entry(vma,
- ht_head(lut, eb->exec[i].handle),
- ctx_node) {
- if (vma->ctx_handle != eb->exec[i].handle)
- continue;
-
- err = eb_add_vma(eb, i, vma);
- if (unlikely(err))
- return err;
- goto next_vma;
- }
-
- if (slow_pass < 0)
- slow_pass = i;
-next_vma: ;
- }
+ for (i = 0; i < eb->buffer_count; i++) {
+ u32 handle = eb->exec[i].handle;
+ struct hlist_head *hl = ht_head(lut, handle);
+ unsigned int flags = 0;
+ struct i915_vma *vma;
- if (slow_pass < 0)
- goto out;
+ hlist_for_each_entry(vma, hl, ctx_node) {
+ GEM_BUG_ON(vma->ctx != eb->ctx);
- spin_lock(&eb->file->table_lock);
- /*
- * Grab a reference to the object and release the lock so we can lookup
- * or create the VMA without using GFP_ATOMIC
- */
- idr = &eb->file->object_idr;
- for (i = slow_pass; i < count; i++) {
- struct drm_i915_gem_object *obj;
+ if (vma->ctx_handle != handle)
+ continue;
- if (eb->vma[i])
- continue;
+ goto add_vma;
+ }
- obj = to_intel_bo(idr_find(idr, eb->exec[i].handle));
+ obj = i915_gem_object_lookup(eb->file, handle);
if (unlikely(!obj)) {
- spin_unlock(&eb->file->table_lock);
- DRM_DEBUG("Invalid object handle %d at index %d\n",
- eb->exec[i].handle, i);
err = -ENOENT;
- goto err;
+ goto err_vma;
}
- eb->vma[i] = (struct i915_vma *)
- ptr_pack_bits(obj, INTERMEDIATE, 1);
- }
- spin_unlock(&eb->file->table_lock);
-
- for (i = slow_pass; i < count; i++) {
- struct drm_i915_gem_object *obj;
- unsigned int is_obj;
-
- obj = (typeof(obj))ptr_unpack_bits(eb->vma[i], &is_obj, 1);
- if (!is_obj)
- continue;
-
- /*
- * NOTE: We can leak any vmas created here when something fails
- * later on. But that's no issue since vma_unbind can deal with
- * vmas which are not actually bound. And since only
- * lookup_or_create exists as an interface to get at the vma
- * from the (obj, vm) we don't run the risk of creating
- * duplicated vmas for the same vm.
- */
vma = i915_vma_instance(obj, eb->vm, NULL);
if (unlikely(IS_ERR(vma))) {
- DRM_DEBUG("Failed to lookup VMA\n");
err = PTR_ERR(vma);
- goto err;
+ goto err_obj;
}
/* First come, first served */
if (!vma->ctx) {
vma->ctx = eb->ctx;
- vma->ctx_handle = eb->exec[i].handle;
- hlist_add_head(&vma->ctx_node,
- ht_head(lut, eb->exec[i].handle));
+ vma->ctx_handle = handle;
+ hlist_add_head(&vma->ctx_node, hl);
lut->ht_count++;
lut->ht_size |= I915_CTX_RESIZE_IN_PROGRESS;
if (i915_vma_is_ggtt(vma)) {
@@ -792,21 +746,19 @@ next_vma: ;
obj->vma_hashed = vma;
}
- i915_vma_get(vma);
+ /* transfer ref to ctx */
+ obj = NULL;
+ } else {
+ flags = __EXEC_OBJECT_HAS_REF;
}
- err = eb_add_vma(eb, i, vma);
+add_vma:
+ err = eb_add_vma(eb, i, vma, flags);
if (unlikely(err))
- goto err;
+ goto err_obj;
GEM_BUG_ON(vma != eb->vma[i]);
GEM_BUG_ON(vma->exec_flags != &eb->flags[i]);
-
- /* Only after we validated the user didn't use our bits */
- if (vma->ctx != eb->ctx) {
- i915_vma_get(vma);
- *vma->exec_flags |= __EXEC_OBJECT_HAS_REF;
- }
}
if (lut->ht_size & I915_CTX_RESIZE_IN_PROGRESS) {
@@ -816,7 +768,6 @@ next_vma: ;
lut->ht_size &= ~I915_CTX_RESIZE_IN_PROGRESS;
}
-out:
/* take note of the batch buffer before we might reorder the lists */
i = eb_batch_index(eb);
eb->batch = eb->vma[i];
@@ -839,14 +790,13 @@ next_vma: ;
eb->args->flags |= __EXEC_VALIDATED;
return eb_reserve(eb);
-err:
- for (i = slow_pass; i < count; i++) {
- if (ptr_unmask_bits(eb->vma[i], 1))
- eb->vma[i] = NULL;
- }
+err_obj:
+ if (obj)
+ i915_gem_object_put(obj);
+err_vma:
+ eb->vma[i] = NULL;
lut->ht_size &= ~I915_CTX_RESIZE_IN_PROGRESS;
return err;
-#undef INTERMEDIATE
}
static struct i915_vma *
@@ -879,7 +829,7 @@ static void eb_release_vmas(const struct i915_execbuffer *eb)
unsigned int flags = eb->flags[i];
if (!vma)
- continue;
+ break;
GEM_BUG_ON(vma->exec_flags != &eb->flags[i]);
vma->exec_flags = NULL;
@@ -2141,8 +2091,8 @@ i915_gem_do_execbuffer(struct drm_device *dev,
args->flags |= __EXEC_HAS_RELOC;
eb.exec = exec;
- eb.vma = memset(exec + args->buffer_count + 1, 0,
- (args->buffer_count + 1) * sizeof(*eb.vma));
+ eb.vma = (struct i915_vma **)(exec + args->buffer_count + 1);
+ eb.vma[0] = NULL;
eb.flags = (unsigned int *)(eb.vma + args->buffer_count + 1);
eb.invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS;
--
2.13.3
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