From 6b057f8ecc43be2e190e53599bdd6b8cc96b6f19 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nicolai=20H=C3=A4hnle?= Date: Mon, 11 Jan 2016 14:54:53 -0500 Subject: [PATCH] vbo: cache/memoize the result of vbo_get_minmax_indices (v3) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Some games developers are unaware that an index buffer in a VBO still needs to be read by the CPU if some varying data comes from a user pointer (unless glDrawRangeElements and friends are used). This is particularly bad when they tell us that the index buffer should live in VRAM. This cache helps, e.g. lifting This War Of Mine (a particularly bad offender) from under 10fps to slightly over 20fps on a Carrizo. Note that there is nothing prohibiting a user from rendering from multiple threads simultaneously with the same index buffer, hence the locking. (The internal buffer map taken for the buffer still leads to a race, but at least the locks are a move in the right direction.) v2: disable the cache on USAGE_TEXTURE_BUFFER as well (Chris Forbes) v3: - use bool instead of GLboolean for MinMaxCacheDirty (Ian Romanick) - replace the sticky USAGE_PERSISTENT_WRITE_MAP bit by a direct AccessFlags check Reviewed-by: Chris Forbes (v2) Reviewed-by: Marek Olšák --- src/mesa/main/bufferobj.c | 12 ++- src/mesa/main/mtypes.h | 4 + src/mesa/vbo/vbo.h | 3 + src/mesa/vbo/vbo_minmax_index.c | 168 ++++++++++++++++++++++++++++++++ 4 files changed, 186 insertions(+), 1 deletion(-) diff --git a/src/mesa/main/bufferobj.c b/src/mesa/main/bufferobj.c index 2fcad6501ae..3d93cf826b2 100644 --- a/src/mesa/main/bufferobj.c +++ b/src/mesa/main/bufferobj.c @@ -458,6 +458,7 @@ _mesa_delete_buffer_object(struct gl_context *ctx, { (void) ctx; + vbo_delete_minmax_cache(bufObj); _mesa_align_free(bufObj->Data); /* assign strange values here to help w/ debugging */ @@ -1528,6 +1529,7 @@ _mesa_buffer_storage(struct gl_context *ctx, struct gl_buffer_object *bufObj, bufObj->Written = GL_TRUE; bufObj->Immutable = GL_TRUE; + bufObj->MinMaxCacheDirty = true; assert(ctx->Driver.BufferData); if (!ctx->Driver.BufferData(ctx, target, size, data, GL_DYNAMIC_DRAW, @@ -1641,6 +1643,7 @@ _mesa_buffer_data(struct gl_context *ctx, struct gl_buffer_object *bufObj, FLUSH_VERTICES(ctx, _NEW_BUFFER_OBJECT); bufObj->Written = GL_TRUE; + bufObj->MinMaxCacheDirty = true; #ifdef VBO_DEBUG printf("glBufferDataARB(%u, sz %ld, from %p, usage 0x%x)\n", @@ -1753,6 +1756,7 @@ _mesa_buffer_sub_data(struct gl_context *ctx, struct gl_buffer_object *bufObj, } bufObj->Written = GL_TRUE; + bufObj->MinMaxCacheDirty = true; assert(ctx->Driver.BufferSubData); ctx->Driver.BufferSubData(ctx, offset, size, data, bufObj); @@ -1872,6 +1876,8 @@ _mesa_clear_buffer_sub_data(struct gl_context *ctx, if (size == 0) return; + bufObj->MinMaxCacheDirty = true; + if (data == NULL) { /* clear to zeros, per the spec */ ctx->Driver.ClearBufferSubData(ctx, offset, size, @@ -2285,6 +2291,8 @@ _mesa_copy_buffer_sub_data(struct gl_context *ctx, } } + dst->MinMaxCacheDirty = true; + ctx->Driver.CopyBufferSubData(ctx, src, dst, readOffset, writeOffset, size); } @@ -2489,8 +2497,10 @@ _mesa_map_buffer_range(struct gl_context *ctx, assert(bufObj->Mappings[MAP_USER].AccessFlags == access); } - if (access & GL_MAP_WRITE_BIT) + if (access & GL_MAP_WRITE_BIT) { bufObj->Written = GL_TRUE; + bufObj->MinMaxCacheDirty = true; + } #ifdef VBO_DEBUG if (strstr(func, "Range") == NULL) { /* If not MapRange */ diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h index 4446d94b407..28aa781790b 100644 --- a/src/mesa/main/mtypes.h +++ b/src/mesa/main/mtypes.h @@ -1282,6 +1282,10 @@ struct gl_buffer_object GLuint NumMapBufferWriteCalls; struct gl_buffer_mapping Mappings[MAP_COUNT]; + + /** Memoization of min/max index computations for static index buffers */ + struct hash_table *MinMaxCache; + bool MinMaxCacheDirty; }; diff --git a/src/mesa/vbo/vbo.h b/src/mesa/vbo/vbo.h index 0b8b6a9de56..6494aa518a2 100644 --- a/src/mesa/vbo/vbo.h +++ b/src/mesa/vbo/vbo.h @@ -180,6 +180,9 @@ vbo_sizeof_ib_type(GLenum type) } } +void +vbo_delete_minmax_cache(struct gl_buffer_object *bufferObj); + void vbo_get_minmax_indices(struct gl_context *ctx, const struct _mesa_prim *prim, const struct _mesa_index_buffer *ib, diff --git a/src/mesa/vbo/vbo_minmax_index.c b/src/mesa/vbo/vbo_minmax_index.c index b43ed983676..1aabab3434f 100644 --- a/src/mesa/vbo/vbo_minmax_index.c +++ b/src/mesa/vbo/vbo_minmax_index.c @@ -32,6 +32,167 @@ #include "main/macros.h" #include "main/sse_minmax.h" #include "x86/common_x86_asm.h" +#include "util/hash_table.h" + + +struct minmax_cache_key { + GLintptr offset; + GLuint count; + GLenum type; +}; + + +struct minmax_cache_entry { + struct minmax_cache_key key; + GLuint min; + GLuint max; +}; + + +static uint32_t +vbo_minmax_cache_hash(const struct minmax_cache_key *key) +{ + return _mesa_hash_data(key, sizeof(*key)); +} + + +static bool +vbo_minmax_cache_key_equal(const struct minmax_cache_key *a, + const struct minmax_cache_key *b) +{ + return (a->offset == b->offset) && (a->count == b->count) && (a->type == b->type); +} + + +static void +vbo_minmax_cache_delete_entry(struct hash_entry *entry) +{ + free(entry->data); +} + + +static GLboolean +vbo_use_minmax_cache(struct gl_buffer_object *bufferObj) +{ + if (bufferObj->UsageHistory & (USAGE_TEXTURE_BUFFER | + USAGE_ATOMIC_COUNTER_BUFFER | + USAGE_SHADER_STORAGE_BUFFER | + USAGE_TRANSFORM_FEEDBACK_BUFFER | + USAGE_PIXEL_PACK_BUFFER)) + return GL_FALSE; + + if ((bufferObj->Mappings[MAP_USER].AccessFlags & + (GL_MAP_PERSISTENT_BIT | GL_MAP_WRITE_BIT)) == + (GL_MAP_PERSISTENT_BIT | GL_MAP_WRITE_BIT)) + return GL_FALSE; + + return GL_TRUE; +} + + +void +vbo_delete_minmax_cache(struct gl_buffer_object *bufferObj) +{ + _mesa_hash_table_destroy(bufferObj->MinMaxCache, vbo_minmax_cache_delete_entry); + bufferObj->MinMaxCache = NULL; +} + + +static GLboolean +vbo_get_minmax_cached(struct gl_buffer_object *bufferObj, + GLenum type, GLintptr offset, GLuint count, + GLuint *min_index, GLuint *max_index) +{ + GLboolean found = GL_FALSE; + struct minmax_cache_key key; + uint32_t hash; + struct hash_entry *result; + + if (!bufferObj->MinMaxCache) + return GL_FALSE; + if (!vbo_use_minmax_cache(bufferObj)) + return GL_FALSE; + + mtx_lock(&bufferObj->Mutex); + + if (bufferObj->MinMaxCacheDirty) { + _mesa_hash_table_clear(bufferObj->MinMaxCache, vbo_minmax_cache_delete_entry); + bufferObj->MinMaxCacheDirty = false; + goto out; + } + + key.type = type; + key.offset = offset; + key.count = count; + hash = vbo_minmax_cache_hash(&key); + result = _mesa_hash_table_search_pre_hashed(bufferObj->MinMaxCache, hash, &key); + if (result) { + struct minmax_cache_entry *entry = result->data; + *min_index = entry->min; + *max_index = entry->max; + found = GL_TRUE; + } + +out: + mtx_unlock(&bufferObj->Mutex); + return found; +} + + +static void +vbo_minmax_cache_store(struct gl_context *ctx, + struct gl_buffer_object *bufferObj, + GLenum type, GLintptr offset, GLuint count, + GLuint min, GLuint max) +{ + struct minmax_cache_entry *entry; + struct hash_entry *table_entry; + uint32_t hash; + + if (!vbo_use_minmax_cache(bufferObj)) + return; + + mtx_lock(&bufferObj->Mutex); + + if (!bufferObj->MinMaxCache) { + bufferObj->MinMaxCache = + _mesa_hash_table_create(NULL, + (uint32_t (*)(const void *))vbo_minmax_cache_hash, + (bool (*)(const void *, const void *))vbo_minmax_cache_key_equal); + if (!bufferObj->MinMaxCache) + goto out; + } + + entry = MALLOC_STRUCT(minmax_cache_entry); + if (!entry) + goto out; + + entry->key.offset = offset; + entry->key.count = count; + entry->key.type = type; + entry->min = min; + entry->max = max; + hash = vbo_minmax_cache_hash(&entry->key); + + table_entry = _mesa_hash_table_search_pre_hashed(bufferObj->MinMaxCache, + hash, &entry->key); + if (table_entry) { + /* It seems like this could happen when two contexts are rendering using + * the same buffer object from multiple threads. + */ + _mesa_debug(ctx, "duplicate entry in minmax cache\n"); + free(entry); + goto out; + } + + table_entry = _mesa_hash_table_insert_pre_hashed(bufferObj->MinMaxCache, + hash, &entry->key, entry); + if (!table_entry) + free(entry); + +out: + mtx_unlock(&bufferObj->Mutex); +} /** @@ -56,6 +217,11 @@ vbo_get_minmax_index(struct gl_context *ctx, indices = (char *) ib->ptr + prim->start * index_size; if (_mesa_is_bufferobj(ib->obj)) { GLsizeiptr size = MIN2(count * index_size, ib->obj->Size); + + if (vbo_get_minmax_cached(ib->obj, ib->type, (GLintptr) indices, count, + min_index, max_index)) + return; + indices = ctx->Driver.MapBufferRange(ctx, (GLintptr) indices, size, GL_MAP_READ_BIT, ib->obj, MAP_INTERNAL); @@ -139,6 +305,8 @@ vbo_get_minmax_index(struct gl_context *ctx, } if (_mesa_is_bufferobj(ib->obj)) { + vbo_minmax_cache_store(ctx, ib->obj, ib->type, prim->start, count, + *min_index, *max_index); ctx->Driver.UnmapBuffer(ctx, ib->obj, MAP_INTERNAL); } } -- 2.30.2