| /* |
| * Copyright 2018 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can |
| * be found in the LICENSE file. |
| * |
| */ |
| |
| #pragma once |
| |
| // |
| // This is a suballocator for a large extent typically less than 4 GB. |
| // |
| // The SKC pipeline will use this for ephemeral host and device memory |
| // allocations. The lifetime of an allocation is typically |
| // milliseconds or less and is associated with either a single kernel |
| // or a sub-pipeline. |
| // |
| // Because of this, a relatively small number of allocations (10's) |
| // will be outstanding at any time so the implementation can |
| // reasonably be very simplistic and optimize for this case. |
| // |
| // Also, if either memory or subbuffer nodes aren't available the |
| // suballocator will block and pump the pipeline's scheduler until it |
| // can proceed. |
| // |
| // Note that this implementation is single-threaded and the |
| // suballocator's state may have been altered after pumping the |
| // scheduler. |
| // |
| |
| #include "types.h" |
| |
| // |
| // It's practical for the subbuf_id to be either 16 bits or maybe even |
| // 8 bits if the number of outstanding subbufs is in the thousands (16 |
| // bits) or under 256 (8 bits). |
| // |
| |
| typedef skc_ushort skc_subbuf_id_t; |
| typedef skc_uint skc_subbuf_size_t; // <4GB |
| // typedef size_t skc_subbuf_size_t; // >4GB |
| |
| // |
| // |
| // |
| |
| struct skc_subbuf |
| { |
| struct skc_subbuf * prev; |
| struct skc_subbuf * next; |
| |
| skc_subbuf_size_t size; |
| skc_subbuf_size_t origin; |
| |
| skc_uint idx; // ids[] index of subbuf in available state |
| skc_uint inuse; |
| }; |
| |
| // |
| // |
| // |
| |
| struct skc_suballocator |
| { |
| struct skc_subbuf * subbufs; |
| |
| skc_subbuf_id_t * ids; // [<-AVAIL-><-empty-><-SPARE->] |
| |
| struct { |
| skc_uint avail; |
| skc_uint spare; |
| } rem; // inuse = count - (avail + spare) |
| |
| skc_uint align; // required pow2 alignment |
| skc_uint count; // number of subbufs |
| |
| skc_subbuf_size_t size; // size of memory extent |
| skc_subbuf_size_t total; |
| |
| char const * name; |
| }; |
| |
| // |
| // |
| // |
| |
| void |
| skc_suballocator_create(struct skc_runtime * const runtime, |
| struct skc_suballocator * const suballocator, |
| char const * const name, |
| skc_uint const subbufs, |
| size_t const align, |
| size_t const size); |
| |
| void |
| skc_suballocator_dispose(struct skc_runtime * const runtime, |
| struct skc_suballocator * const suballocator); |
| |
| // |
| // |
| // |
| |
| size_t |
| skc_suballocator_subbuf_alloc(struct skc_suballocator * const suballocator, |
| struct skc_scheduler * const scheduler, |
| size_t const size, |
| skc_subbuf_id_t * const subbuf_id, |
| size_t * const subbuf_size); |
| |
| void |
| skc_suballocator_subbuf_free(struct skc_suballocator * const suballocator, |
| skc_subbuf_id_t subbuf_id); |
| |
| // |
| // |
| // |