[PATCH 64/64] drm/i915/gem: Acquire all vma/objects under reservation_ww_class
Chris Wilson
chris at chris-wilson.co.uk
Tue Jun 23 16:11:46 UTC 2020
In order to actually handle eviction and what not, we need to process
all the objects together under a common lock, reservation_ww_class. As
such, do a memory reservation pass after looking up the object/vma,
which then feeds into the rest of execbuf [relocation, cmdparsing,
flushing and ofc execution].
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 120 +++++++++++++++---
1 file changed, 99 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index a0389c49361b..f7d90e20c1e1 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -53,10 +53,9 @@ struct eb_vma_array {
#define __EXEC_OBJECT_HAS_PIN BIT(31)
#define __EXEC_OBJECT_HAS_FENCE BIT(30)
-#define __EXEC_OBJECT_HAS_PAGES BIT(29)
-#define __EXEC_OBJECT_NEEDS_MAP BIT(28)
-#define __EXEC_OBJECT_NEEDS_BIAS BIT(27)
-#define __EXEC_OBJECT_INTERNAL_FLAGS (~0u << 27) /* all of the above */
+#define __EXEC_OBJECT_NEEDS_MAP BIT(29)
+#define __EXEC_OBJECT_NEEDS_BIAS BIT(28)
+#define __EXEC_OBJECT_INTERNAL_FLAGS (~0u << 28) /* all of the above */
#define __EXEC_HAS_RELOC BIT(31)
#define __EXEC_INTERNAL_FLAGS (~0u << 31)
@@ -241,6 +240,8 @@ struct i915_execbuffer {
struct intel_context *context; /* logical state for the request */
struct i915_gem_context *gem_context; /** caller's context */
+ struct dma_fence *mm_fence;
+
struct i915_request *request; /** our request to build */
struct eb_vma *batch; /** identity of the batch obj/vma */
struct i915_vma *trampoline; /** trampoline used for chaining */
@@ -331,12 +332,7 @@ static inline void eb_unreserve_vma(struct eb_vma *ev)
if (ev->flags & __EXEC_OBJECT_HAS_PIN)
__i915_vma_unpin(vma);
- if (ev->flags & __EXEC_OBJECT_HAS_PAGES)
- i915_gem_object_unpin_pages(vma->obj);
-
- ev->flags &= ~(__EXEC_OBJECT_HAS_PIN |
- __EXEC_OBJECT_HAS_FENCE |
- __EXEC_OBJECT_HAS_PAGES);
+ ev->flags &= ~(__EXEC_OBJECT_HAS_PIN | __EXEC_OBJECT_HAS_FENCE);
}
static void eb_vma_array_destroy(struct kref *kref)
@@ -667,6 +663,55 @@ eb_add_vma(struct i915_execbuffer *eb,
list_add_tail(&ev->lock_link, &eb->lock);
}
+static int eb_vma_get_pages(struct i915_execbuffer *eb,
+ struct eb_vma *ev,
+ u64 idx)
+{
+ struct i915_vma *vma = ev->vma;
+ int err;
+
+ /* XXX also preallocate PD for vma */
+
+ err = ____i915_gem_object_get_pages_async(vma->obj);
+ if (err)
+ return err;
+
+ return i915_active_ref(&vma->obj->mm.active, idx, eb->mm_fence);
+}
+
+static int eb_reserve_mm(struct i915_execbuffer *eb)
+{
+ const u64 idx = eb->context->timeline->fence_context;
+ struct ww_acquire_ctx acquire;
+ struct eb_vma *ev;
+ int err;
+
+ eb->mm_fence = __dma_fence_create_proxy(0, 0);
+ if (!eb->mm_fence)
+ return -ENOMEM;
+
+ ww_acquire_init(&acquire, &reservation_ww_class);
+
+ err = eb_lock_vma(eb, &acquire);
+ if (err)
+ goto out;
+
+ ww_acquire_done(&acquire);
+
+ list_for_each_entry(ev, &eb->lock, lock_link) {
+ struct i915_vma *vma = ev->vma;
+
+ if (err == 0)
+ err = eb_vma_get_pages(eb, ev, idx);
+
+ i915_vma_unlock(vma);
+ }
+
+out:
+ ww_acquire_fini(&acquire);
+ return err;
+}
+
struct eb_vm_work {
struct dma_fence_work base;
struct list_head unbound;
@@ -1314,20 +1359,9 @@ static int eb_vm_throttle(struct eb_vm_work *work)
static int eb_prepare_vma(struct eb_vma *ev)
{
- struct i915_vma *vma = ev->vma;
- int err;
-
ev->hole.flags = 0;
ev->bind_flags = 0;
- if (!(ev->flags & __EXEC_OBJECT_HAS_PAGES)) {
- err = i915_gem_object_pin_pages(vma->obj);
- if (err)
- return err;
-
- ev->flags |= __EXEC_OBJECT_HAS_PAGES;
- }
-
return 0;
}
@@ -2415,6 +2449,10 @@ static int eb_relocate(struct i915_execbuffer *eb)
if (err)
return err;
+ err = eb_reserve_mm(eb);
+ if (err)
+ return err;
+
err = eb_reserve_vm(eb);
if (err)
return err;
@@ -2846,6 +2884,12 @@ static int eb_submit(struct i915_execbuffer *eb, struct i915_vma *batch)
{
int err;
+ if (eb->mm_fence) {
+ dma_fence_proxy_set_real(eb->mm_fence, &eb->request->fence);
+ dma_fence_put(eb->mm_fence);
+ eb->mm_fence = NULL;
+ }
+
if (eb->reloc_cache.fence) {
err = i915_request_await_dma_fence(eb->request,
&eb->reloc_cache.rq->fence);
@@ -3341,6 +3385,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
eb.batch_start_offset = args->batch_start_offset;
eb.batch_len = args->batch_len;
eb.trampoline = NULL;
+ eb.mm_fence = NULL;
eb.batch_flags = 0;
if (args->flags & I915_EXEC_SECURE) {
@@ -3535,6 +3580,39 @@ i915_gem_do_execbuffer(struct drm_device *dev,
eb_reloc_signal(&eb, eb.reloc_cache.rq);
if (eb.trampoline)
i915_vma_unpin(eb.trampoline);
+ if (eb.mm_fence) {
+ struct intel_timeline *tl = eb.context->timeline;
+ struct dma_fence *prev =
+ i915_active_fence_get(&tl->last_request);
+
+ /*
+ * We have to rollback our per-timeline reference token.
+ *
+ * However as we did not take note of the previous token on
+ * each object, we substitute the previous fence in our timeline
+ * as a replacement for this submission token. If there is no
+ * prior fence in the timeline, the reference token will be
+ * released.
+ *
+ * If the object was unused (or idle) in this timeline, and
+ * was instantiated for this execbuf, it will now persist until
+ * the end of the previous request. Possibly keeping it around
+ * until the user's next execbuf, but at any rate keeping it
+ * alive when it's not yet in use.
+ *
+ * If the object was only being used earlier in the timeline,
+ * we've just extended it's live range to the end of the
+ * current timeline, which is a fair approximation of the
+ * intended acquisition.
+ *
+ * If the object was last used in the previous request, there
+ * is no change in live range.
+ */
+ dma_fence_proxy_set_real(eb.mm_fence, prev);
+ dma_fence_put(prev);
+
+ dma_fence_put(eb.mm_fence);
+ }
eb_unpin_engine(&eb);
err_context:
i915_gem_context_put(eb.gem_context);
--
2.20.1
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