From 77bbdcdfcd8ad354a6e556b7440ea160fa62db85 Mon Sep 17 00:00:00 2001 From: Samuel Pitoiset Date: Tue, 16 May 2017 10:11:54 +0200 Subject: [PATCH] radeonsi: add a slab allocator for bindless descriptors MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit For each texture/image handles, we need to allocate a new buffer for the bindless descriptor. But when the number of buffers added to the current CS becomes high, the overhead in the winsys (and in the kernel) is important. To reduce this bottleneck, the idea is to suballocate the bindless descriptors using a slab similar to the one used in the winsys. Currently, a buffer can hold 1024 bindless descriptors but this limit is arbitrary and could be changed in the future for some reasons. Once a slab is allocated the "base" buffer is added to a per-context list. Signed-off-by: Samuel Pitoiset Reviewed-by: Marek Olšák --- src/gallium/drivers/radeonsi/si_descriptors.c | 84 +++++++++++++++++++++++++++ src/gallium/drivers/radeonsi/si_pipe.c | 12 ++++ src/gallium/drivers/radeonsi/si_pipe.h | 15 +++++ src/gallium/drivers/radeonsi/si_state.h | 8 +++ 4 files changed, 119 insertions(+) diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c b/src/gallium/drivers/radeonsi/si_descriptors.c index 32d6cbe..7d0a8f9 100644 --- a/src/gallium/drivers/radeonsi/si_descriptors.c +++ b/src/gallium/drivers/radeonsi/si_descriptors.c @@ -2036,6 +2036,90 @@ void si_emit_compute_shader_userdata(struct si_context *sctx) sctx->shader_pointers_dirty &= ~compute_mask; } +/* BINDLESS */ + +struct si_bindless_descriptor_slab +{ + struct pb_slab base; + struct r600_resource *buffer; + struct si_bindless_descriptor *entries; +}; + +bool si_bindless_descriptor_can_reclaim_slab(void *priv, + struct pb_slab_entry *entry) +{ + /* Do not allow to reclaim any bindless descriptors for now because the + * GPU might be using them. This should be improved later on. + */ + return false; +} + +struct pb_slab *si_bindless_descriptor_slab_alloc(void *priv, unsigned heap, + unsigned entry_size, + unsigned group_index) +{ + struct si_context *sctx = priv; + struct si_screen *sscreen = sctx->screen; + struct si_bindless_descriptor_slab *slab; + + slab = CALLOC_STRUCT(si_bindless_descriptor_slab); + if (!slab) + return NULL; + + /* Create a buffer in VRAM for 1024 bindless descriptors. */ + slab->buffer = (struct r600_resource *) + pipe_buffer_create(&sscreen->b.b, 0, + PIPE_USAGE_DEFAULT, 64 * 1024); + if (!slab->buffer) + goto fail; + + slab->base.num_entries = slab->buffer->bo_size / entry_size; + slab->base.num_free = slab->base.num_entries; + slab->entries = CALLOC(slab->base.num_entries, sizeof(*slab->entries)); + if (!slab->entries) + goto fail_buffer; + + LIST_INITHEAD(&slab->base.free); + + for (unsigned i = 0; i < slab->base.num_entries; ++i) { + struct si_bindless_descriptor *desc = &slab->entries[i]; + + desc->entry.slab = &slab->base; + desc->entry.group_index = group_index; + desc->buffer = slab->buffer; + desc->offset = i * entry_size; + + LIST_ADDTAIL(&desc->entry.head, &slab->base.free); + } + + /* Add the descriptor to the per-context list. */ + util_dynarray_append(&sctx->bindless_descriptors, + struct r600_resource *, slab->buffer); + + return &slab->base; + +fail_buffer: + r600_resource_reference(&slab->buffer, NULL); +fail: + FREE(slab); + return NULL; +} + +void si_bindless_descriptor_slab_free(void *priv, struct pb_slab *pslab) +{ + struct si_context *sctx = priv; + struct si_bindless_descriptor_slab *slab = + (struct si_bindless_descriptor_slab *)pslab; + + /* Remove the descriptor from the per-context list. */ + util_dynarray_delete_unordered(&sctx->bindless_descriptors, + struct r600_resource *, slab->buffer); + + r600_resource_reference(&slab->buffer, NULL); + FREE(slab->entries); + FREE(slab); +} + /* INIT/DEINIT/UPLOAD */ /* GFX9 has only 4KB of CE, while previous chips had 32KB. In order diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c index 031e473..14fe9dd 100644 --- a/src/gallium/drivers/radeonsi/si_pipe.c +++ b/src/gallium/drivers/radeonsi/si_pipe.c @@ -94,6 +94,9 @@ static void si_destroy_context(struct pipe_context *context) r600_resource_reference(&sctx->last_trace_buf, NULL); radeon_clear_saved_cs(&sctx->last_gfx); + pb_slabs_deinit(&sctx->bindless_descriptor_slabs); + util_dynarray_fini(&sctx->bindless_descriptors); + FREE(sctx); } @@ -316,6 +319,15 @@ static struct pipe_context *si_create_context(struct pipe_screen *screen, sctx->tm = si_create_llvm_target_machine(sscreen); + /* Create a slab allocator for all bindless descriptors. */ + if (!pb_slabs_init(&sctx->bindless_descriptor_slabs, 6, 6, 1, sctx, + si_bindless_descriptor_can_reclaim_slab, + si_bindless_descriptor_slab_alloc, + si_bindless_descriptor_slab_free)) + goto fail; + + util_dynarray_init(&sctx->bindless_descriptors, NULL); + return &sctx->b.b; fail: fprintf(stderr, "radeonsi: Failed to create a context.\n"); diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h index eef05cf..0d8128c 100644 --- a/src/gallium/drivers/radeonsi/si_pipe.h +++ b/src/gallium/drivers/radeonsi/si_pipe.h @@ -28,6 +28,8 @@ #include "si_shader.h" +#include "util/u_dynarray.h" + #ifdef PIPE_ARCH_BIG_ENDIAN #define SI_BIG_ENDIAN 1 #else @@ -228,6 +230,13 @@ union si_vgt_param_key { uint32_t index; }; +struct si_bindless_descriptor +{ + struct pb_slab_entry entry; + struct r600_resource *buffer; + unsigned offset; +}; + struct si_context { struct r600_common_context b; struct blitter_context *blitter; @@ -390,6 +399,12 @@ struct si_context { /* Precomputed IA_MULTI_VGT_PARAM */ union si_vgt_param_key ia_multi_vgt_param_key; unsigned ia_multi_vgt_param[SI_NUM_VGT_PARAM_STATES]; + + /* Slab allocator for bindless descriptors. */ + struct pb_slabs bindless_descriptor_slabs; + + /* Bindless descriptors. */ + struct util_dynarray bindless_descriptors; }; /* cik_sdma.c */ diff --git a/src/gallium/drivers/radeonsi/si_state.h b/src/gallium/drivers/radeonsi/si_state.h index d8bf13e..55227a1 100644 --- a/src/gallium/drivers/radeonsi/si_state.h +++ b/src/gallium/drivers/radeonsi/si_state.h @@ -30,6 +30,8 @@ #include "si_pm4.h" #include "radeon/r600_pipe_common.h" +#include "pipebuffer/pb_slab.h" + #define SI_NUM_GRAPHICS_SHADERS (PIPE_SHADER_TESS_EVAL+1) #define SI_NUM_SHADERS (PIPE_SHADER_COMPUTE+1) @@ -340,6 +342,12 @@ void si_set_active_descriptors(struct si_context *sctx, unsigned desc_idx, uint64_t new_active_mask); void si_set_active_descriptors_for_shader(struct si_context *sctx, struct si_shader_selector *sel); +bool si_bindless_descriptor_can_reclaim_slab(void *priv, + struct pb_slab_entry *entry); +struct pb_slab *si_bindless_descriptor_slab_alloc(void *priv, unsigned heap, + unsigned entry_size, + unsigned group_index); +void si_bindless_descriptor_slab_free(void *priv, struct pb_slab *pslab); /* si_state.c */ struct si_shader_selector; -- 2.7.4