[Intel-gfx] [PATCH] drm/i915/gem: Split eb_vma into its own allocation
Chris Wilson
chris at chris-wilson.co.uk
Mon Mar 30 13:37:10 UTC 2020
Use a separate array allocation for the execbuf vma, so that we can
track their lifetime independently from the copy of the user arguments.
With luck, this has a secondary benefit of splitting the malloc size to
within reason and avoid vmalloc. The downside is that we might require
two separate vmallocs -- but much less likely.
In the process, this prevents a memory leak on the ww_mutex error
unwind.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1390
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 131 ++++++++++--------
1 file changed, 73 insertions(+), 58 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index f347e595a773..cda35e6dfc44 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -40,6 +40,11 @@ struct eb_vma {
u32 handle;
};
+struct eb_vma_array {
+ struct kref kref;
+ struct eb_vma vma[];
+};
+
enum {
FORCE_CPU_RELOC = 1,
FORCE_GTT_RELOC,
@@ -52,7 +57,6 @@ enum {
#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_OBJECT_RESERVED (__EXEC_OBJECT_HAS_PIN | __EXEC_OBJECT_HAS_FENCE)
#define __EXEC_HAS_RELOC BIT(31)
#define __EXEC_INTERNAL_FLAGS (~0u << 31)
@@ -283,6 +287,7 @@ struct i915_execbuffer {
*/
int lut_size;
struct hlist_head *buckets; /** ht for relocation handles */
+ struct eb_vma_array *array;
};
static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
@@ -292,8 +297,62 @@ static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
eb->args->batch_len);
}
+static struct eb_vma_array *eb_vma_array_create(unsigned int count)
+{
+ struct eb_vma_array *arr;
+
+ arr = kvmalloc(struct_size(arr, vma, count), GFP_KERNEL | __GFP_NOWARN);
+ if (!arr)
+ return NULL;
+
+ kref_init(&arr->kref);
+ arr->vma[0].vma = NULL;
+
+ return arr;
+}
+
+static inline void eb_unreserve_vma(struct eb_vma *ev)
+{
+ struct i915_vma *vma = ev->vma;
+
+ if (unlikely(ev->flags & __EXEC_OBJECT_HAS_FENCE))
+ __i915_vma_unpin_fence(vma);
+
+ if (ev->flags & __EXEC_OBJECT_HAS_PIN)
+ __i915_vma_unpin(vma);
+
+ ev->flags &= ~(__EXEC_OBJECT_HAS_PIN |
+ __EXEC_OBJECT_HAS_FENCE);
+}
+
+static void eb_vma_array_destroy(struct kref *kref)
+{
+ struct eb_vma_array *arr = container_of(kref, typeof(*arr), kref);
+ struct eb_vma *ev = arr->vma;
+
+ while (ev->vma) {
+ eb_unreserve_vma(ev);
+ i915_vma_put(ev->vma);
+ ev++;
+ }
+
+ kvfree(arr);
+}
+
+static void eb_vma_array_put(struct eb_vma_array *arr)
+{
+ kref_put(&arr->kref, eb_vma_array_destroy);
+}
+
static int eb_create(struct i915_execbuffer *eb)
{
+ /* Allocate an extra slot for use by the command parser + sentinel */
+ eb->array = eb_vma_array_create(eb->buffer_count + 2);
+ if (!eb->array)
+ return -ENOMEM;
+
+ eb->vma = eb->array->vma;
+
if (!(eb->args->flags & I915_EXEC_HANDLE_LUT)) {
unsigned int size = 1 + ilog2(eb->buffer_count);
@@ -327,8 +386,10 @@ static int eb_create(struct i915_execbuffer *eb)
break;
} while (--size);
- if (unlikely(!size))
+ if (unlikely(!size)) {
+ eb_vma_array_put(eb->array);
return -ENOMEM;
+ }
eb->lut_size = size;
} else {
@@ -402,26 +463,6 @@ eb_pin_vma(struct i915_execbuffer *eb,
return !eb_vma_misplaced(entry, vma, ev->flags);
}
-static inline void __eb_unreserve_vma(struct i915_vma *vma, unsigned int flags)
-{
- GEM_BUG_ON(!(flags & __EXEC_OBJECT_HAS_PIN));
-
- if (unlikely(flags & __EXEC_OBJECT_HAS_FENCE))
- __i915_vma_unpin_fence(vma);
-
- __i915_vma_unpin(vma);
-}
-
-static inline void
-eb_unreserve_vma(struct eb_vma *ev)
-{
- if (!(ev->flags & __EXEC_OBJECT_HAS_PIN))
- return;
-
- __eb_unreserve_vma(ev->vma, ev->flags);
- ev->flags &= ~__EXEC_OBJECT_RESERVED;
-}
-
static int
eb_validate_vma(struct i915_execbuffer *eb,
struct drm_i915_gem_exec_object2 *entry,
@@ -863,31 +904,13 @@ eb_get_vma(const struct i915_execbuffer *eb, unsigned long handle)
}
}
-static void eb_release_vmas(const struct i915_execbuffer *eb)
-{
- const unsigned int count = eb->buffer_count;
- unsigned int i;
-
- for (i = 0; i < count; i++) {
- struct eb_vma *ev = &eb->vma[i];
- struct i915_vma *vma = ev->vma;
-
- if (!vma)
- break;
-
- eb->vma[i].vma = NULL;
-
- if (ev->flags & __EXEC_OBJECT_HAS_PIN)
- __eb_unreserve_vma(vma, ev->flags);
-
- i915_vma_put(vma);
- }
-}
-
static void eb_destroy(const struct i915_execbuffer *eb)
{
GEM_BUG_ON(eb->reloc_cache.rq);
+ if (eb->array)
+ eb_vma_array_put(eb->array);
+
if (eb->lut_size > 0)
kfree(eb->buckets);
}
@@ -1635,19 +1658,15 @@ static int eb_move_to_gpu(struct i915_execbuffer *eb)
err = i915_vma_move_to_active(vma, eb->request, flags);
i915_vma_unlock(vma);
-
- __eb_unreserve_vma(vma, flags);
- i915_vma_put(vma);
-
- ev->vma = NULL;
+ eb_unreserve_vma(ev);
}
ww_acquire_fini(&acquire);
+ eb_vma_array_put(fetch_and_zero(&eb->array));
+
if (unlikely(err))
goto err_skip;
- eb->exec = NULL;
-
/* Unconditionally flush any chipset caches (for streaming writes). */
intel_gt_chipset_flush(eb->engine->gt);
return 0;
@@ -1899,6 +1918,7 @@ static int eb_parse(struct i915_execbuffer *eb)
eb->vma[eb->buffer_count].vma = i915_vma_get(shadow);
eb->vma[eb->buffer_count].flags = __EXEC_OBJECT_HAS_PIN;
eb->batch = &eb->vma[eb->buffer_count++];
+ eb->vma[eb->buffer_count].vma = NULL;
eb->trampoline = trampoline;
eb->batch_start_offset = 0;
@@ -2422,8 +2442,6 @@ i915_gem_do_execbuffer(struct drm_device *dev,
args->flags |= __EXEC_HAS_RELOC;
eb.exec = exec;
- eb.vma = (struct eb_vma *)(exec + args->buffer_count + 1);
- eb.vma[0].vma = NULL;
eb.invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS;
reloc_cache_init(&eb.reloc_cache, eb.i915);
@@ -2630,8 +2648,6 @@ i915_gem_do_execbuffer(struct drm_device *dev,
if (batch->private)
intel_engine_pool_put(batch->private);
err_vma:
- if (eb.exec)
- eb_release_vmas(&eb);
if (eb.trampoline)
i915_vma_unpin(eb.trampoline);
eb_unpin_engine(&eb);
@@ -2651,7 +2667,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
static size_t eb_element_size(void)
{
- return sizeof(struct drm_i915_gem_exec_object2) + sizeof(struct eb_vma);
+ return sizeof(struct drm_i915_gem_exec_object2);
}
static bool check_buffer_count(size_t count)
@@ -2707,7 +2723,7 @@ i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
/* Copy in the exec list from userland */
exec_list = kvmalloc_array(count, sizeof(*exec_list),
__GFP_NOWARN | GFP_KERNEL);
- exec2_list = kvmalloc_array(count + 1, eb_element_size(),
+ exec2_list = kvmalloc_array(count, eb_element_size(),
__GFP_NOWARN | GFP_KERNEL);
if (exec_list == NULL || exec2_list == NULL) {
drm_dbg(&i915->drm,
@@ -2785,8 +2801,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
if (err)
return err;
- /* Allocate an extra slot for use by the command parser */
- exec2_list = kvmalloc_array(count + 1, eb_element_size(),
+ exec2_list = kvmalloc_array(count, eb_element_size(),
__GFP_NOWARN | GFP_KERNEL);
if (exec2_list == NULL) {
drm_dbg(&i915->drm, "Failed to allocate exec list for %zd buffers\n",
--
2.20.1
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