[PATCH 7/9] drm/i915: Remove short-term pins from execbuf, v6.
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Tue Jan 4 12:53:37 UTC 2022
Add a flag PIN_VALIDATE, to indicate we don't need to pin and only
protected by the object lock.
This removes the need to unpin, which is done by just releasing the
lock.
eb_reserve is slightly reworked for readability, but the same steps
are still done:
- First pass pins with NONBLOCK.
- Second pass unbinds all objects first, then pins.
- Third pass is only called when not all objects are softpinned, and
unbinds all objects, then calls i915_gem_evict_vm(), then pins.
Changes since v1:
- Split out eb_reserve() into separate functions for readability.
Changes since v2:
- Make batch buffer mappable on platforms where only GGTT is available,
to prevent moving the batch buffer during relocations.
Changes since v3:
- Preserve current behavior for batch buffer, instead be cautious when
calling i915_gem_object_ggtt_pin_ww, and re-use the current batch vma
if it's inside ggtt and map-and-fenceable.
- Remove impossible condition check from eb_reserve. (Matt)
Changes since v5:
- Do not even temporarily pin, just call i915_gem_evict_vm() and mark
all vma's as unpinned.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>
---
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 220 +++++++++---------
drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c | 1 -
drivers/gpu/drm/i915/i915_gem_gtt.h | 1 +
drivers/gpu/drm/i915/i915_vma.c | 24 +-
4 files changed, 128 insertions(+), 118 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index ae556dc52669..ea157905b452 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -441,7 +441,7 @@ eb_pin_vma(struct i915_execbuffer *eb,
else
pin_flags = entry->offset & PIN_OFFSET_MASK;
- pin_flags |= PIN_USER | PIN_NOEVICT | PIN_OFFSET_FIXED;
+ pin_flags |= PIN_USER | PIN_NOEVICT | PIN_OFFSET_FIXED | PIN_VALIDATE;
if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_GTT))
pin_flags |= PIN_GLOBAL;
@@ -459,17 +459,15 @@ eb_pin_vma(struct i915_execbuffer *eb,
entry->pad_to_size,
entry->alignment,
eb_pin_flags(entry, ev->flags) |
- PIN_USER | PIN_NOEVICT);
+ PIN_USER | PIN_NOEVICT | PIN_VALIDATE);
if (unlikely(err))
return err;
}
if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_FENCE)) {
err = i915_vma_pin_fence(vma);
- if (unlikely(err)) {
- i915_vma_unpin(vma);
+ if (unlikely(err))
return err;
- }
if (vma->fence)
ev->flags |= __EXEC_OBJECT_HAS_FENCE;
@@ -485,13 +483,9 @@ eb_pin_vma(struct i915_execbuffer *eb,
static inline void
eb_unreserve_vma(struct eb_vma *ev)
{
- if (!(ev->flags & __EXEC_OBJECT_HAS_PIN))
- return;
-
if (unlikely(ev->flags & __EXEC_OBJECT_HAS_FENCE))
__i915_vma_unpin_fence(ev->vma);
- __i915_vma_unpin(ev->vma);
ev->flags &= ~__EXEC_OBJECT_RESERVED;
}
@@ -684,10 +678,8 @@ static int eb_reserve_vma(struct i915_execbuffer *eb,
if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_FENCE)) {
err = i915_vma_pin_fence(vma);
- if (unlikely(err)) {
- i915_vma_unpin(vma);
+ if (unlikely(err))
return err;
- }
if (vma->fence)
ev->flags |= __EXEC_OBJECT_HAS_FENCE;
@@ -699,85 +691,95 @@ static int eb_reserve_vma(struct i915_execbuffer *eb,
return 0;
}
-static int eb_reserve(struct i915_execbuffer *eb)
+static bool eb_unbind(struct i915_execbuffer *eb, bool force)
{
const unsigned int count = eb->buffer_count;
- unsigned int pin_flags = PIN_USER | PIN_NONBLOCK;
+ unsigned int i;
struct list_head last;
+ bool unpinned = false;
+
+ /* Resort *all* the objects into priority order */
+ INIT_LIST_HEAD(&eb->unbound);
+ INIT_LIST_HEAD(&last);
+
+ for (i = 0; i < count; i++) {
+ struct eb_vma *ev = &eb->vma[i];
+ unsigned int flags = ev->flags;
+
+ if (!force && flags & EXEC_OBJECT_PINNED &&
+ flags & __EXEC_OBJECT_HAS_PIN)
+ continue;
+
+ unpinned = true;
+ eb_unreserve_vma(ev);
+
+ if (flags & EXEC_OBJECT_PINNED)
+ /* Pinned must have their slot */
+ list_add(&ev->bind_link, &eb->unbound);
+ else if (flags & __EXEC_OBJECT_NEEDS_MAP)
+ /* Map require the lowest 256MiB (aperture) */
+ list_add_tail(&ev->bind_link, &eb->unbound);
+ else if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS))
+ /* Prioritise 4GiB region for restricted bo */
+ list_add(&ev->bind_link, &last);
+ else
+ list_add_tail(&ev->bind_link, &last);
+ }
+
+ list_splice_tail(&last, &eb->unbound);
+ return unpinned;
+}
+
+static int eb_reserve(struct i915_execbuffer *eb)
+{
struct eb_vma *ev;
- unsigned int i, pass;
+ unsigned int pass;
int err = 0;
+ bool unpinned;
/*
* Attempt to pin all of the buffers into the GTT.
- * This is done in 3 phases:
+ * This is done in 2 phases:
*
- * 1a. Unbind all objects that do not match the GTT constraints for
- * the execbuffer (fenceable, mappable, alignment etc).
- * 1b. Increment pin count for already bound objects.
- * 2. Bind new objects.
- * 3. Decrement pin count.
+ * 1. Unbind all objects that do not match the GTT constraints for
+ * the execbuffer (fenceable, mappable, alignment etc).
+ * 2. Bind new objects.
*
* This avoid unnecessary unbinding of later objects in order to make
* room for the earlier objects *unless* we need to defragment.
+ *
+ * Defragmenting is skipped if all objects are pinned at a fixed location.
*/
- pass = 0;
- do {
- list_for_each_entry(ev, &eb->unbound, bind_link) {
- err = eb_reserve_vma(eb, ev, pin_flags);
- if (err)
- break;
- }
- if (err != -ENOSPC)
- return err;
+ for (pass = 0; pass <= 2; pass++) {
+ int pin_flags = PIN_USER | PIN_VALIDATE;
- /* Resort *all* the objects into priority order */
- INIT_LIST_HEAD(&eb->unbound);
- INIT_LIST_HEAD(&last);
- for (i = 0; i < count; i++) {
- unsigned int flags;
+ if (pass == 0)
+ pin_flags |= PIN_NONBLOCK;
- ev = &eb->vma[i];
- flags = ev->flags;
- if (flags & EXEC_OBJECT_PINNED &&
- flags & __EXEC_OBJECT_HAS_PIN)
- continue;
+ if (pass >= 1)
+ unpinned = eb_unbind(eb, pass == 2);
- eb_unreserve_vma(ev);
-
- if (flags & EXEC_OBJECT_PINNED)
- /* Pinned must have their slot */
- list_add(&ev->bind_link, &eb->unbound);
- else if (flags & __EXEC_OBJECT_NEEDS_MAP)
- /* Map require the lowest 256MiB (aperture) */
- list_add_tail(&ev->bind_link, &eb->unbound);
- else if (!(flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS))
- /* Prioritise 4GiB region for restricted bo */
- list_add(&ev->bind_link, &last);
- else
- list_add_tail(&ev->bind_link, &last);
- }
- list_splice_tail(&last, &eb->unbound);
-
- switch (pass++) {
- case 0:
- break;
-
- case 1:
- /* Too fragmented, unbind everything and retry */
- mutex_lock(&eb->context->vm->mutex);
- err = i915_gem_evict_vm(eb->context->vm, &eb->ww);
- mutex_unlock(&eb->context->vm->mutex);
+ if (pass == 2) {
+ err = mutex_lock_interruptible(&eb->context->vm->mutex);
+ if (!err) {
+ err = i915_gem_evict_vm(eb->context->vm, &eb->ww);
+ mutex_unlock(&eb->context->vm->mutex);
+ }
if (err)
return err;
- break;
+ }
- default:
- return -ENOSPC;
+ list_for_each_entry(ev, &eb->unbound, bind_link) {
+ err = eb_reserve_vma(eb, ev, pin_flags);
+ if (err)
+ break;
}
- pin_flags = PIN_USER;
- } while (1);
+ if (err != -ENOSPC)
+ break;
+ }
+
+ return err;
}
static int eb_select_context(struct i915_execbuffer *eb)
@@ -1225,10 +1227,11 @@ static void *reloc_kmap(struct drm_i915_gem_object *obj,
return vaddr;
}
-static void *reloc_iomap(struct drm_i915_gem_object *obj,
+static void *reloc_iomap(struct i915_vma *batch,
struct i915_execbuffer *eb,
unsigned long page)
{
+ struct drm_i915_gem_object *obj = batch->obj;
struct reloc_cache *cache = &eb->reloc_cache;
struct i915_ggtt *ggtt = cache_to_ggtt(cache);
unsigned long offset;
@@ -1238,7 +1241,7 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
intel_gt_flush_ggtt_writes(ggtt->vm.gt);
io_mapping_unmap_atomic((void __force __iomem *) unmask_page(cache->vaddr));
} else {
- struct i915_vma *vma;
+ struct i915_vma *vma = ERR_PTR(-ENODEV);
int err;
if (i915_gem_object_is_tiled(obj))
@@ -1251,10 +1254,23 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
if (err)
return ERR_PTR(err);
- vma = i915_gem_object_ggtt_pin_ww(obj, &eb->ww, NULL, 0, 0,
- PIN_MAPPABLE |
- PIN_NONBLOCK /* NOWARN */ |
- PIN_NOEVICT);
+ /*
+ * i915_gem_object_ggtt_pin_ww may attempt to remove the batch
+ * VMA from the object list because we no longer pin.
+ *
+ * Only attempt to pin the batch buffer to ggtt if the current batch
+ * is not inside ggtt, or the batch buffer is not misplaced.
+ */
+ if (!i915_is_ggtt(batch->vm)) {
+ vma = i915_gem_object_ggtt_pin_ww(obj, &eb->ww, NULL, 0, 0,
+ PIN_MAPPABLE |
+ PIN_NONBLOCK /* NOWARN */ |
+ PIN_NOEVICT);
+ } else if (i915_vma_is_map_and_fenceable(batch)) {
+ __i915_vma_pin(batch);
+ vma = batch;
+ }
+
if (vma == ERR_PTR(-EDEADLK))
return vma;
@@ -1292,7 +1308,7 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj,
return vaddr;
}
-static void *reloc_vaddr(struct drm_i915_gem_object *obj,
+static void *reloc_vaddr(struct i915_vma *vma,
struct i915_execbuffer *eb,
unsigned long page)
{
@@ -1304,9 +1320,9 @@ static void *reloc_vaddr(struct drm_i915_gem_object *obj,
} else {
vaddr = NULL;
if ((cache->vaddr & KMAP) == 0)
- vaddr = reloc_iomap(obj, eb, page);
+ vaddr = reloc_iomap(vma, eb, page);
if (!vaddr)
- vaddr = reloc_kmap(obj, cache, page);
+ vaddr = reloc_kmap(vma->obj, cache, page);
}
return vaddr;
@@ -1347,7 +1363,7 @@ relocate_entry(struct i915_vma *vma,
void *vaddr;
repeat:
- vaddr = reloc_vaddr(vma->obj, eb,
+ vaddr = reloc_vaddr(vma, eb,
offset >> PAGE_SHIFT);
if (IS_ERR(vaddr))
return PTR_ERR(vaddr);
@@ -2209,7 +2225,7 @@ shadow_batch_pin(struct i915_execbuffer *eb,
if (IS_ERR(vma))
return vma;
- err = i915_vma_pin_ww(vma, &eb->ww, 0, 0, flags);
+ err = i915_vma_pin_ww(vma, &eb->ww, 0, 0, flags | PIN_VALIDATE);
if (err)
return ERR_PTR(err);
@@ -2223,7 +2239,7 @@ static struct i915_vma *eb_dispatch_secure(struct i915_execbuffer *eb, struct i9
* batch" bit. Hence we need to pin secure batches into the global gtt.
* hsw should have this fixed, but bdw mucks it up again. */
if (eb->batch_flags & I915_DISPATCH_SECURE)
- return i915_gem_object_ggtt_pin_ww(vma->obj, &eb->ww, NULL, 0, 0, 0);
+ return i915_gem_object_ggtt_pin_ww(vma->obj, &eb->ww, NULL, 0, 0, PIN_VALIDATE);
return NULL;
}
@@ -2274,13 +2290,12 @@ static int eb_parse(struct i915_execbuffer *eb)
err = i915_gem_object_lock(pool->obj, &eb->ww);
if (err)
- goto err;
+ return err;
shadow = shadow_batch_pin(eb, pool->obj, eb->context->vm, PIN_USER);
- if (IS_ERR(shadow)) {
- err = PTR_ERR(shadow);
- goto err;
- }
+ if (IS_ERR(shadow))
+ return PTR_ERR(shadow);
+
intel_gt_buffer_pool_mark_used(pool);
i915_gem_object_set_readonly(shadow->obj);
shadow->private = pool;
@@ -2292,25 +2307,21 @@ static int eb_parse(struct i915_execbuffer *eb)
shadow = shadow_batch_pin(eb, pool->obj,
&eb->gt->ggtt->vm,
PIN_GLOBAL);
- if (IS_ERR(shadow)) {
- err = PTR_ERR(shadow);
- shadow = trampoline;
- goto err_shadow;
- }
+ if (IS_ERR(shadow))
+ return PTR_ERR(shadow);
+
shadow->private = pool;
eb->batch_flags |= I915_DISPATCH_SECURE;
}
batch = eb_dispatch_secure(eb, shadow);
- if (IS_ERR(batch)) {
- err = PTR_ERR(batch);
- goto err_trampoline;
- }
+ if (IS_ERR(batch))
+ return PTR_ERR(batch);
err = dma_resv_reserve_shared(shadow->obj->base.resv, 1);
if (err)
- goto err_trampoline;
+ return err;
err = intel_engine_cmd_parser(eb->context->engine,
eb->batches[0]->vma,
@@ -2318,7 +2329,7 @@ static int eb_parse(struct i915_execbuffer *eb)
eb->batch_len[0],
shadow, trampoline);
if (err)
- goto err_unpin_batch;
+ return err;
eb->batches[0] = &eb->vma[eb->buffer_count++];
eb->batches[0]->vma = i915_vma_get(shadow);
@@ -2337,17 +2348,6 @@ static int eb_parse(struct i915_execbuffer *eb)
eb->batches[0]->vma = i915_vma_get(batch);
}
return 0;
-
-err_unpin_batch:
- if (batch)
- i915_vma_unpin(batch);
-err_trampoline:
- if (trampoline)
- i915_vma_unpin(trampoline);
-err_shadow:
- i915_vma_unpin(shadow);
-err:
- return err;
}
static int eb_request_submit(struct i915_execbuffer *eb,
@@ -3468,8 +3468,6 @@ i915_gem_do_execbuffer(struct drm_device *dev,
err_vma:
eb_release_vmas(&eb, true);
- if (eb.trampoline)
- i915_vma_unpin(eb.trampoline);
WARN_ON(err == -EDEADLK);
i915_gem_ww_ctx_fini(&eb.ww);
diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c b/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c
index f8948de72036..bbcd0522f68e 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c
@@ -425,7 +425,6 @@ int i915_vma_pin_fence(struct i915_vma *vma)
* must keep the device awake whilst using the fence.
*/
assert_rpm_wakelock_held(vma->vm->gt->uncore->rpm);
- GEM_BUG_ON(!i915_vma_is_pinned(vma));
GEM_BUG_ON(!i915_vma_is_ggtt(vma));
err = mutex_lock_interruptible(&vma->vm->mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index e4938aba3fe9..8c2f57eb5dda 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -44,6 +44,7 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
#define PIN_HIGH BIT_ULL(5)
#define PIN_OFFSET_BIAS BIT_ULL(6)
#define PIN_OFFSET_FIXED BIT_ULL(7)
+#define PIN_VALIDATE BIT_ULL(8) /* validate placement only, no need to call unpin() */
#define PIN_GLOBAL BIT_ULL(10) /* I915_VMA_GLOBAL_BIND */
#define PIN_USER BIT_ULL(11) /* I915_VMA_LOCAL_BIND */
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 8859feb7d131..5f43100638b5 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -779,6 +779,15 @@ static bool try_qad_pin(struct i915_vma *vma, unsigned int flags)
unsigned int bound;
bound = atomic_read(&vma->flags);
+
+ if (flags & PIN_VALIDATE) {
+ flags &= I915_VMA_BIND_MASK;
+
+ return (flags & bound) == flags;
+ }
+
+ /* with the lock mandatory for unbind, we don't race here */
+ flags &= I915_VMA_BIND_MASK;
do {
if (unlikely(flags & ~bound))
return false;
@@ -1254,7 +1263,7 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
GEM_BUG_ON(!(flags & (PIN_USER | PIN_GLOBAL)));
/* First try and grab the pin without rebinding the vma */
- if (try_qad_pin(vma, flags & I915_VMA_BIND_MASK))
+ if (try_qad_pin(vma, flags))
return 0;
err = i915_vma_get_pages(vma);
@@ -1336,7 +1345,8 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
}
if (unlikely(!(flags & ~bound & I915_VMA_BIND_MASK))) {
- __i915_vma_pin(vma);
+ if (!(flags & PIN_VALIDATE))
+ __i915_vma_pin(vma);
goto err_unlock;
}
@@ -1365,8 +1375,10 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
atomic_add(I915_VMA_PAGES_ACTIVE, &vma->pages_count);
list_move_tail(&vma->vm_link, &vma->vm->bound_list);
- __i915_vma_pin(vma);
- GEM_BUG_ON(!i915_vma_is_pinned(vma));
+ if (!(flags & PIN_VALIDATE)) {
+ __i915_vma_pin(vma);
+ GEM_BUG_ON(!i915_vma_is_pinned(vma));
+ }
GEM_BUG_ON(!i915_vma_is_bound(vma, flags));
GEM_BUG_ON(i915_vma_misplaced(vma, size, alignment, flags));
@@ -1626,8 +1638,6 @@ static int __i915_vma_move_to_active(struct i915_vma *vma, struct i915_request *
{
int err;
- GEM_BUG_ON(!i915_vma_is_pinned(vma));
-
/* Wait for the vma to be bound before we start! */
err = __i915_request_await_bind(rq, vma);
if (err)
@@ -1646,6 +1656,8 @@ int _i915_vma_move_to_active(struct i915_vma *vma,
assert_object_held(obj);
+ GEM_BUG_ON(!vma->pages);
+
err = __i915_vma_move_to_active(vma, rq);
if (unlikely(err))
return err;
--
2.34.1
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