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authorKenneth Graunke <[email protected]>2019-04-25 18:30:57 -0700
committerKenneth Graunke <[email protected]>2019-05-03 19:50:26 -0700
commit694d1a08d3e5883d97d5352895f8431f76596cb8 (patch)
tree5a2b8023916afa378e87143aeadf8e3761f5ea2b
parentbd4b18d255581e71c152cdef0f475091f6a2a132 (diff)
iris: Delete bucketing allocators
These add a lot of complexity, and I currently can't measure any performance benefit from having them. In the past, I seem to recall seeing a benefit in drawoverhead scores, but currently it looks like dropping them is either a wash or 1-2% faster. Drop them to simplify allocations.
-rw-r--r--src/gallium/drivers/iris/iris_bufmgr.c170
1 files changed, 3 insertions, 167 deletions
diff --git a/src/gallium/drivers/iris/iris_bufmgr.c b/src/gallium/drivers/iris/iris_bufmgr.c
index 11b3885be29..5b807e0fbc8 100644
--- a/src/gallium/drivers/iris/iris_bufmgr.c
+++ b/src/gallium/drivers/iris/iris_bufmgr.c
@@ -132,41 +132,12 @@ memzone_name(enum iris_memory_zone memzone)
return names[memzone];
}
-/**
- * Iris fixed-size bucketing VMA allocator.
- *
- * The BO cache maintains "cache buckets" for buffers of various sizes.
- * All buffers in a given bucket are identically sized - when allocating,
- * we always round up to the bucket size. This means that virtually all
- * allocations are fixed-size; only buffers which are too large to fit in
- * a bucket can be variably-sized.
- *
- * We create an allocator for each bucket. Each contains a free-list, where
- * each node contains a <starting address, 64-bit bitmap> pair. Each bit
- * represents a bucket-sized block of memory. (At the first level, each
- * bit corresponds to a page. For the second bucket, bits correspond to
- * two pages, and so on.) 1 means a block is free, and 0 means it's in-use.
- * The lowest bit in the bitmap is for the first block.
- *
- * This makes allocations cheap - any bit of any node will do. We can pick
- * the head of the list and use ffs() to find a free block. If there are
- * none, we allocate 64 blocks from a larger allocator - either a bigger
- * bucketing allocator, or a fallback top-level allocator for large objects.
- */
-struct vma_bucket_node {
- uint64_t start_address;
- uint64_t bitmap;
-};
-
struct bo_cache_bucket {
/** List of cached BOs. */
struct list_head head;
/** Size of this bucket, in bytes. */
uint64_t size;
-
- /** List of vma_bucket_nodes. */
- struct util_dynarray vma_list[IRIS_MEMZONE_COUNT];
};
struct iris_bufmgr {
@@ -283,121 +254,6 @@ iris_memzone_for_address(uint64_t address)
return IRIS_MEMZONE_SHADER;
}
-static uint64_t
-bucket_vma_alloc(struct iris_bufmgr *bufmgr,
- struct bo_cache_bucket *bucket,
- enum iris_memory_zone memzone)
-{
- struct util_dynarray *vma_list = &bucket->vma_list[memzone];
- struct vma_bucket_node *node;
-
- if (vma_list->size == 0) {
- /* This bucket allocator is out of space - allocate a new block of
- * memory for 64 blocks from a larger allocator (either a larger
- * bucket or util_vma).
- *
- * We align the address to the node size (64 blocks) so that
- * bucket_vma_free can easily compute the starting address of this
- * block by rounding any address we return down to the node size.
- *
- * Set the first bit used, and return the start address.
- */
- const uint64_t node_size = 64ull * bucket->size;
- node = util_dynarray_grow(vma_list, sizeof(struct vma_bucket_node));
-
- if (unlikely(!node))
- return 0ull;
-
- uint64_t addr = vma_alloc(bufmgr, memzone, node_size, node_size);
- node->start_address = gen_48b_address(addr);
- node->bitmap = ~1ull;
- return node->start_address;
- }
-
- /* Pick any bit from any node - they're all the right size and free. */
- node = util_dynarray_top_ptr(vma_list, struct vma_bucket_node);
- int bit = ffsll(node->bitmap) - 1;
- assert(bit >= 0 && bit <= 63);
-
- /* Reserve the memory by clearing the bit. */
- assert((node->bitmap & (1ull << bit)) != 0ull);
- node->bitmap &= ~(1ull << bit);
-
- uint64_t addr = node->start_address + bit * bucket->size;
-
- /* If this node is now completely full, remove it from the free list. */
- if (node->bitmap == 0ull) {
- (void) util_dynarray_pop(vma_list, struct vma_bucket_node);
- }
-
- return addr;
-}
-
-static void
-bucket_vma_free(struct bo_cache_bucket *bucket, uint64_t address)
-{
- enum iris_memory_zone memzone = iris_memzone_for_address(address);
- struct util_dynarray *vma_list = &bucket->vma_list[memzone];
- const uint64_t node_bytes = 64ull * bucket->size;
- struct vma_bucket_node *node = NULL;
-
- /* bucket_vma_alloc allocates 64 blocks at a time, and aligns it to
- * that 64 block size. So, we can round down to get the starting address.
- */
- uint64_t start = (address / node_bytes) * node_bytes;
-
- /* Dividing the offset from start by bucket size gives us the bit index. */
- int bit = (address - start) / bucket->size;
-
- assert(start + bit * bucket->size == address);
-
- util_dynarray_foreach(vma_list, struct vma_bucket_node, cur) {
- if (cur->start_address == start) {
- node = cur;
- break;
- }
- }
-
- if (!node) {
- /* No node - the whole group of 64 blocks must have been in-use. */
- node = util_dynarray_grow(vma_list, sizeof(struct vma_bucket_node));
-
- if (unlikely(!node))
- return; /* bogus, leaks some GPU VMA, but nothing we can do... */
-
- node->start_address = start;
- node->bitmap = 0ull;
- }
-
- /* Set the bit to return the memory. */
- assert((node->bitmap & (1ull << bit)) == 0ull);
- node->bitmap |= 1ull << bit;
-
- /* The block might be entirely free now, and if so, we could return it
- * to the larger allocator. But we may as well hang on to it, in case
- * we get more allocations at this block size.
- */
-}
-
-static struct bo_cache_bucket *
-get_bucket_allocator(struct iris_bufmgr *bufmgr,
- enum iris_memory_zone memzone,
- uint64_t size)
-{
- /* Skip using the bucket allocator for very large sizes, as it allocates
- * 64 of them and this can balloon rather quickly.
- */
- if (size > 1024 * PAGE_SIZE)
- return NULL;
-
- struct bo_cache_bucket *bucket = bucket_for_size(bufmgr, size);
-
- if (bucket && bucket->size == size)
- return bucket;
-
- return NULL;
-}
-
/**
* Allocate a section of virtual memory for a buffer, assigning an address.
*
@@ -420,16 +276,8 @@ vma_alloc(struct iris_bufmgr *bufmgr,
if (memzone == IRIS_MEMZONE_BINDER)
return IRIS_MEMZONE_BINDER_START;
- struct bo_cache_bucket *bucket =
- get_bucket_allocator(bufmgr, memzone, size);
- uint64_t addr;
-
- if (bucket) {
- addr = bucket_vma_alloc(bufmgr, bucket, memzone);
- } else {
- addr = util_vma_heap_alloc(&bufmgr->vma_allocator[memzone], size,
- alignment);
- }
+ uint64_t addr =
+ util_vma_heap_alloc(&bufmgr->vma_allocator[memzone], size, alignment);
assert((addr >> 48ull) == 0);
assert((addr % alignment) == 0);
@@ -457,14 +305,7 @@ vma_free(struct iris_bufmgr *bufmgr,
if (memzone == IRIS_MEMZONE_BINDER)
return;
- struct bo_cache_bucket *bucket =
- get_bucket_allocator(bufmgr, memzone, size);
-
- if (bucket) {
- bucket_vma_free(bucket, address);
- } else {
- util_vma_heap_free(&bufmgr->vma_allocator[memzone], address, size);
- }
+ util_vma_heap_free(&bufmgr->vma_allocator[memzone], address, size);
}
int
@@ -1321,9 +1162,6 @@ iris_bufmgr_destroy(struct iris_bufmgr *bufmgr)
bo_free(bo);
}
-
- for (int z = 0; z < IRIS_MEMZONE_COUNT; z++)
- util_dynarray_fini(&bucket->vma_list[z]);
}
_mesa_hash_table_destroy(bufmgr->name_table, NULL);
@@ -1529,8 +1367,6 @@ add_bucket(struct iris_bufmgr *bufmgr, int size)
assert(i < ARRAY_SIZE(bufmgr->cache_bucket));
list_inithead(&bufmgr->cache_bucket[i].head);
- for (int z = 0; z < IRIS_MEMZONE_COUNT; z++)
- util_dynarray_init(&bufmgr->cache_bucket[i].vma_list[z], NULL);
bufmgr->cache_bucket[i].size = size;
bufmgr->num_buckets++;