| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can |
| * be found in the LICENSE file. |
| * |
| */ |
| |
| // |
| // FIXME -- a pre-allocation step could load the path header quads and |
| // total up the number of blocks in the workgroup or subgroup |
| // minimizing the number of later atomics adds. |
| // |
| |
| #include "block.h" |
| #include "path.h" |
| #include "common.h" |
| #include "atomic_cl.h" |
| #include "block_pool_cl.h" |
| #include "kernel_cl_12.h" |
| |
| // |
| // |
| // |
| |
| #define SKC_PATHS_RECLAIM_SUBGROUP_SIZE_MASK (SKC_PATHS_RECLAIM_SUBGROUP_SIZE - 1) |
| |
| #define SKC_PATHS_RECLAIM_SUBGROUP_ELEMS (SKC_PATHS_RECLAIM_SUBGROUP_SIZE * SKC_PATHS_RECLAIM_LOCAL_ELEMS) |
| |
| #define SKC_PATHS_RECLAIM_X (SKC_DEVICE_BLOCK_WORDS / SKC_PATHS_RECLAIM_SUBGROUP_ELEMS) |
| |
| // |
| // |
| // |
| |
| #if ( SKC_PATHS_RECLAIM_X == 1 ) |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND() SKC_EXPAND_1() |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST 0 |
| |
| #elif ( SKC_PATHS_RECLAIM_X == 2 ) |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND() SKC_EXPAND_2() |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST 1 |
| |
| #elif ( SKC_PATHS_RECLAIM_X == 4 ) |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND() SKC_EXPAND_4() |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST 3 |
| |
| #elif ( SKC_PATHS_RECLAIM_X == 8 ) |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND() SKC_EXPAND_8() |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST 7 |
| |
| #elif ( SKC_PATHS_RECLAIM_X == 16) |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND() SKC_EXPAND_16() |
| #define SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST 15 |
| |
| #else |
| #error "MISSING SKC_PATHS_RECLAIM_X" |
| #endif |
| |
| // |
| // FIXME -- slate these for replacement |
| // |
| |
| #define SKC_BROADCAST(E,S,I) \ |
| sub_group_broadcast(E,S - I * SKC_PATHS_RECLAIM_SUBGROUP_SIZE) |
| |
| #define SKC_BROADCAST_LAST_HELPER(E,I) \ |
| sub_group_broadcast(E,SKC_PATHS_RECLAIM_SUBGROUP_SIZE - 1) |
| |
| #define SKC_BROADCAST_LAST(E,I) \ |
| SKC_BROADCAST_LAST_HELPER(E,I) |
| |
| // |
| // COMPILE-TIME PREDICATES |
| // |
| |
| #define SKC_PATHS_RECLAIM_ELEM_GTE(X,I) \ |
| SKC_GTE_MACRO(X,(I+1) * SKC_PATHS_RECLAIM_SUBGROUP_SIZE) |
| |
| #define SKC_PATHS_RECLAIM_ELEM_IN_RANGE(X,I) \ |
| (skc_bool)SKC_GTE_MACRO(X, I * SKC_PATHS_RECLAIM_SUBGROUP_SIZE) && \ |
| (skc_bool)SKC_LT_MACRO(X,(I+1) * SKC_PATHS_RECLAIM_SUBGROUP_SIZE) |
| |
| #define SKC_PATHS_RECLAIM_ENTIRELY_HEADER(I) \ |
| SKC_PATHS_RECLAIM_ELEM_GTE(SKC_PATH_HEAD_WORDS,I) |
| |
| #define SKC_PATHS_RECLAIM_PARTIALLY_HEADER(I) \ |
| SKC_PATHS_RECLAIM_ELEM_IN_RANGE(SKC_PATH_HEAD_WORDS,I) |
| |
| // |
| // RUN-TIME PREDICATES |
| // |
| |
| #define SKC_PATHS_RECLAIM_IS_HEADER(I) \ |
| (get_sub_group_local_id() + I * SKC_PATHS_RECLAIM_SUBGROUP_SIZE < SKC_PATH_HEAD_WORDS) |
| |
| // |
| // FIXME -- THIS BITFIELD SCAN APPROACH CAN BE PARAMETERIZED FOR ALL |
| // POSSIBLE PRACTICAL POWER-OF-TWO SUBGROUP AND SUBBLOCKS-PER-BLOCK |
| // COMBOS (NOT NECESSARILY POW2) |
| // |
| // FOR WIDER SUBGROUPS WITH BIG BLOCKS, WE WILL WANT TO USE A VECTOR |
| // UINT TYPE INSTEAD OF A ULONG. |
| // |
| |
| #define SKC_PATHS_RECLAIM_PACKED_COUNT_BITS SKC_PATHS_RECLAIM_SUBGROUP_SIZE_LOG2 |
| #define SKC_PATHS_RECLAIM_PACKED_COUNT_DECLARE skc_uint |
| |
| // |
| // |
| // |
| |
| #define SKC_PATHS_RECLAIM_PACKED_COUNT_MASK SKC_BITS_TO_MASK(SKC_PATHS_RECLAIM_PACKED_COUNT_BITS) |
| |
| #define SKC_PATHS_RECLAIM_PACKED_COUNT_IS_BLOCK(E,I) \ |
| (((E) & SKC_DEVICE_SUBBLOCKS_PER_BLOCK_MASK) \ |
| ? 0 : (1u << SKC_PATHS_RECLAIM_PACKED_COUNT_BITS * I)) |
| |
| #define SKC_PATHS_RECLAIM_PACKED_COUNT_SCAN_EXCLUSIVE_ADD(S,C) \ |
| S = sub_group_scan_exclusive_add(C) |
| |
| #define SKC_PATHS_RECLAIM_PACKED_COUNT_GET(C,I) \ |
| (((C) >> (SKC_PATHS_RECLAIM_PACKED_COUNT_BITS * I)) & SKC_PATHS_RECLAIM_PACKED_COUNT_MASK) |
| |
| // |
| // |
| // |
| |
| struct skc_reclaim |
| { |
| skc_path_h aN[SKC_RECLAIM_ARRAY_SIZE]; |
| }; |
| |
| __kernel |
| SKC_PATHS_RECLAIM_KERNEL_ATTRIBS |
| void |
| skc_kernel_paths_reclaim(__global skc_block_id_t * const bp_ids, // block pool ids ring |
| __global skc_uint * const bp_elems, // block pool blocks |
| __global skc_uint volatile * const bp_atomics, // read/write atomics |
| skc_uint const bp_mask, // pow2 modulo mask for block pool ring |
| __global skc_block_id_t const * const map, // path host-to-device map |
| struct skc_reclaim const reclaim) // array of host path ids |
| { |
| #if (__OPENCL_VERSION__ < 200) |
| skc_uint const reclaim_stride = get_num_sub_groups(); |
| #else |
| skc_uint const reclaim_stride = get_enqueued_num_sub_groups(); // 2.0 supports non-uniform workgroups |
| #endif |
| skc_uint reclaim_idx = get_group_id(0) * reclaim_stride + get_sub_group_id(); |
| |
| #if 0 |
| // |
| // NOTE -- FOR NOW, THIS KERNEL ALWAYS LAUNCHES FIXED SIZE GRIDS BUT |
| // WE MIGHT WANT TO HAVE THE GRID LIMIT ITSELF TO A FRACTIONAL |
| // MULTIPROCESSOR IN ORDER TO MINIMIZE THE IMPACT OF A LARGE |
| // RECLAMATION JOB ON THE REST OF THE PIPELINE. |
| // |
| for (; reclaim_idx < SKC_RECLAIM_ARRAY_SIZE; reclaim_idx+=reclaim_stride) |
| #endif |
| { |
| // get host path id |
| skc_path_h const path = reclaim.aN[reclaim_idx]; |
| |
| // get the path header block from the map |
| skc_block_id_t id = map[path]; |
| |
| // |
| // blindly load all of the head elements into registers |
| // |
| skc_uint const head_idx = id * SKC_DEVICE_SUBBLOCK_WORDS + get_sub_group_local_id(); |
| |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| skc_uint h##I = bp_elems[head_idx + I * SKC_PATHS_RECLAIM_SUBGROUP_SIZE]; |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // |
| // pick out count.nodes and count.prims from the header |
| // |
| skc_uint count_blocks, count_nodes; |
| |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| if (SKC_PATHS_RECLAIM_ELEM_IN_RANGE(SKC_PATH_HEAD_OFFSET_BLOCKS,I)) { \ |
| count_blocks = SKC_BROADCAST(h##I,SKC_PATH_HEAD_OFFSET_BLOCKS,I); \ |
| } \ |
| if (SKC_PATHS_RECLAIM_ELEM_IN_RANGE(SKC_PATH_HEAD_OFFSET_NODES,I)) { \ |
| count_nodes = SKC_BROADCAST(h##I,SKC_PATH_HEAD_OFFSET_NODES,I); \ |
| } |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| #if 0 |
| if (get_sub_group_local_id() == 0) { |
| printf("reclaim paths: %9u / %5u / %5u\n",path,count_blocks,count_nodes); |
| } |
| #endif |
| |
| // |
| // acquire a span in the block pool ids ring for reclaimed ids |
| // |
| // FIXME count_blocks and atomic add can be done in same lane |
| // |
| skc_uint bp_ids_base = 0; |
| |
| if (get_sub_group_local_id() == 0) { |
| bp_ids_base = SKC_ATOMIC_ADD_GLOBAL_RELAXED_SUBGROUP(bp_atomics+SKC_BP_ATOMIC_OFFSET_WRITES,count_blocks); |
| |
| #if 0 |
| printf("paths: bp_ids_base = %u\n",bp_ids_base); |
| #endif |
| } |
| |
| bp_ids_base = sub_group_broadcast(bp_ids_base,0); |
| |
| // |
| // shift away the tagged block id's tag |
| // |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| if (!SKC_PATHS_RECLAIM_ENTIRELY_HEADER(I)) { \ |
| h##I = h##I >> SKC_TAGGED_BLOCK_ID_BITS_TAG; \ |
| } |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // |
| // swap current id with next |
| // |
| if (get_sub_group_local_id() == SKC_PATHS_RECLAIM_SUBGROUP_SIZE - 1) |
| { |
| skc_block_id_t const next = SKC_CONCAT(h,SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST); |
| |
| SKC_CONCAT(h,SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST) = id; |
| |
| id = next; |
| } |
| |
| // |
| // - we'll skip subgroups that are entirely header |
| // |
| // - but we need to mark any header elements that partially fill |
| // a subgroup as invalid tagged block ids |
| // |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| if (!SKC_PATHS_RECLAIM_ENTIRELY_HEADER(I)) { \ |
| if (SKC_PATHS_RECLAIM_PARTIALLY_HEADER(I)) { \ |
| if (SKC_PATHS_RECLAIM_IS_HEADER(I)) { \ |
| h##I = SKC_TAGGED_BLOCK_ID_INVALID; \ |
| } \ |
| } \ |
| } |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| { |
| // |
| // count reclaimable blocks in each lane |
| // |
| SKC_PATHS_RECLAIM_PACKED_COUNT_DECLARE packed_count = ( 0 ); |
| |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| if (!SKC_PATHS_RECLAIM_ENTIRELY_HEADER(I)) { \ |
| packed_count |= SKC_PATHS_RECLAIM_PACKED_COUNT_IS_BLOCK(h##I,I); \ |
| } |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // |
| // scan to find index of each block |
| // |
| SKC_PATHS_RECLAIM_PACKED_COUNT_DECLARE packed_index = ( 0 ); |
| |
| SKC_PATHS_RECLAIM_PACKED_COUNT_SCAN_EXCLUSIVE_ADD(packed_index,packed_count); |
| |
| // |
| // store blocks back to ring |
| // |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| if (!SKC_PATHS_RECLAIM_ENTIRELY_HEADER(I)) { \ |
| skc_uint const index = SKC_PATHS_RECLAIM_PACKED_COUNT_GET(packed_index,I); \ |
| skc_uint const count = SKC_PATHS_RECLAIM_PACKED_COUNT_GET(packed_count,I); \ |
| skc_uint const bp_ids_idx = (bp_ids_base + index) & bp_mask; \ |
| if (count > 0) { \ |
| bp_ids[bp_ids_idx] = h##I; \ |
| } \ |
| skc_uint const total = index + count; \ |
| bp_ids_base += sub_group_broadcast(total,SKC_PATHS_RECLAIM_SUBGROUP_SIZE-1); \ |
| } |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // printf("P %7u ! %u\n",bp_ids_idx,h##I); |
| } |
| |
| // |
| // we're done if it was just the header |
| // |
| if (count_nodes == 0) |
| return; |
| |
| // |
| // otherwise, walk the nodes |
| // |
| do { |
| // id of next block is in last lane |
| id = sub_group_broadcast(id,SKC_PATHS_RECLAIM_SUBGROUP_SIZE-1); |
| |
| // get index of each element |
| skc_uint const node_idx = id * SKC_DEVICE_SUBBLOCK_WORDS + get_sub_group_local_id(); |
| |
| // |
| // blindly load all of the node elements into registers |
| // |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| skc_uint n##I = bp_elems[node_idx + I * SKC_PATHS_RECLAIM_SUBGROUP_SIZE]; |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // |
| // shift away the tagged block id's tag |
| // |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| n##I = n##I >> SKC_TAGGED_BLOCK_ID_BITS_TAG; |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // |
| // swap current id with next |
| // |
| if (get_sub_group_local_id() == SKC_PATHS_RECLAIM_SUBGROUP_SIZE - 1) |
| { |
| skc_block_id_t const next = SKC_CONCAT(n,SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST); |
| |
| SKC_CONCAT(n,SKC_PATHS_RECLAIM_BLOCK_EXPAND_I_LAST) = id; |
| |
| id = next; |
| } |
| |
| // |
| // count reclaimable blocks in each lane |
| // |
| SKC_PATHS_RECLAIM_PACKED_COUNT_DECLARE packed_count = ( 0 ); |
| |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) \ |
| packed_count |= SKC_PATHS_RECLAIM_PACKED_COUNT_IS_BLOCK(n##I,I); |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // |
| // scan to find index of each block |
| // |
| SKC_PATHS_RECLAIM_PACKED_COUNT_DECLARE packed_index = ( 0 ); |
| |
| SKC_PATHS_RECLAIM_PACKED_COUNT_SCAN_EXCLUSIVE_ADD(packed_index,packed_count); |
| |
| // |
| // store blocks back to ring |
| // |
| #undef SKC_EXPAND_X |
| #define SKC_EXPAND_X(I,S,C,P,R) { \ |
| skc_uint const index = SKC_PATHS_RECLAIM_PACKED_COUNT_GET(packed_index,I); \ |
| skc_uint const count = SKC_PATHS_RECLAIM_PACKED_COUNT_GET(packed_count,I); \ |
| skc_uint const bp_ids_idx = (bp_ids_base + index) & bp_mask; \ |
| if (count > 0) { \ |
| bp_ids[bp_ids_idx] = n##I; \ |
| } \ |
| skc_uint const total = index + count; \ |
| bp_ids_base += sub_group_broadcast(total,SKC_PATHS_RECLAIM_SUBGROUP_SIZE-1); \ |
| } |
| |
| SKC_PATHS_RECLAIM_BLOCK_EXPAND(); |
| |
| // printf("P %7u ! %u\n",bp_ids_idx,n##I); |
| |
| // any more nodes? |
| } while (--count_nodes > 0); |
| } |
| } |
| |
| // |
| // |
| // |
