From 13b8ac29f7a3c458895c6ae73882eb191c5bb7d0 Mon Sep 17 00:00:00 2001 From: junyao <1071307515@qq.com> Date: Fri, 30 Oct 2026 17:39:20 +0000 Subject: [PATCH] =?UTF-8?q?perf:=20=E5=A4=9A=20shard=20=E6=97=B6=E9=94=81?= =?UTF-8?q?=E6=95=B0=E7=BB=84=E6=8C=89=2064B=20=E5=AF=B9=E9=BD=90=EF=BC=8C?= =?UTF-8?q?=E6=B6=88=E9=99=A4=E7=9B=B8=E9=82=BB=20shard=20=E7=9A=84?= =?UTF-8?q?=E4=BC=AA=E5=85=B1=E4=BA=AB?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit v0.1.7 的锁数组起点是 56 + 64*48 = 3128（mod 64 = 56），每把锁的锁字和 上一个 shard 的 hot_id1/hot_base 在同一条 cache line 上。home shard 按 步长 9 分配，8 线程以内恰好不相邻；从第 9 个线程起相邻 shard 同时有人 用，吞吐从 8 线程的 157 Mops/s 掉到 10 线程的 63 Mops/s。 - 多 shard 时锁数组起点对齐到 64B（相对 meta；mmap 得到的 meta 天然满足）， 头部多 8 字节，sbo_meta_size / sbo_init 同步。 - sbo_meta_t 用原 _pad 的 1 字节记 layout；v0.1.7 创建的多 shard meta （layout 0）由 sbo_meta_ok 拒绝，不会被误读。 - 单 shard 布局逐字节不变（kvspace-c 依赖这一点）。 --- include/slotsboxmalloc/slotsboxobj.h | 29 +++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/include/slotsboxmalloc/slotsboxobj.h b/include/slotsboxmalloc/slotsboxobj.h index 814506e..d99d608 100644 --- a/include/slotsboxmalloc/slotsboxobj.h +++ b/include/slotsboxmalloc/slotsboxobj.h @@ -123,9 +123,16 @@ typedef struct { uint8_t slot_shift; uint8_t box_off; uint32_t max_blocks; - uint8_t _pad[2]; + uint8_t layout; /* SBO_LAYOUT_LOCK64 when root_slots > 1, else 0 */ + uint8_t _pad[1]; } sbo_meta_t; +/* Multi-shard metas place the lock array on a 64-byte boundary relative to + * meta (pass a 64-byte aligned meta, e.g. from mmap) so each shard's lock and + * hot cache own one cache line. Multi-shard metas from v0.1.7 (layout 0) are + * rejected rather than misread; the single-shard layout is unchanged. */ +#define SBO_LAYOUT_LOCK64 1 + int sbo_init(void *metaptr, size_t head_size, size_t data_size); uint64_t sbo_alloc(void *metaptr, size_t size); void sbo_free(void *metaptr, uint64_t obj_offset); @@ -144,12 +151,18 @@ size_t sbo_meta_size(size_t data_size, size_t per_slot_pool); static inline blocks_meta_t *sbo_pool_meta(sbo_meta_t *meta, uint8_t si) { return (blocks_meta_t *)((uint8_t *)(meta + 1)) + si; } +static inline size_t sbo_lock_off(uint8_t shards) { + size_t off = sizeof(sbo_meta_t) + (size_t)shards * sizeof(blocks_meta_t); + return shards > 1 ? (off + 63) & ~(size_t)63 : off; +} +static inline size_t sbo_header_size(uint8_t shards) { + return sbo_lock_off(shards) + (size_t)shards * sizeof(sbo_lock_t); +} static inline sbo_lock_t *sbo_pool_lock(sbo_meta_t *meta, uint8_t si) { - return (sbo_lock_t *)((uint8_t *)(meta + 1) + meta->root_slots * sizeof(blocks_meta_t)) + si; + return (sbo_lock_t *)((uint8_t *)meta + sbo_lock_off(meta->root_slots)) + si; } static inline uint8_t *sbo_pool_mem(sbo_meta_t *meta, uint8_t si) { - return (uint8_t *)(meta + 1) - + meta->root_slots * SBO_POOL_HDR + return (uint8_t *)meta + sbo_header_size(meta->root_slots) + si * meta->per_slot_meta; } @@ -461,6 +474,7 @@ static inline bool sbo_magic_ok(const sbo_meta_t *meta) { static inline bool sbo_meta_ok(const sbo_meta_t *meta) { if (!sbo_magic_ok(meta)) return false; if (meta->root_slots != 1 && meta->root_slots != SBO_MAX_SHARDS) return false; + if (meta->root_slots > 1 && meta->layout != SBO_LAYOUT_LOCK64) return false; if (meta->shard_mask != meta->root_slots - 1) return false; if (meta->slot_shift < 9 || meta->slot_shift >= 64) return false; if (meta->data_size == 0 @@ -512,7 +526,7 @@ int sbo_init(void *metaptr, size_t head_size, size_t data_size) { uint8_t shards = sbo_shards_for_data(data_size); size_t header_base, per_slot_meta; for (;;) { - header_base = sizeof(sbo_meta_t) + (size_t)shards * SBO_POOL_HDR; + header_base = sbo_header_size(shards); if (head_size <= header_base) return -1; per_slot_meta = ((head_size - header_base) / shards) & ~(size_t)7; if (shards == 1 @@ -528,7 +542,8 @@ int sbo_init(void *metaptr, size_t head_size, size_t data_size) { meta->shard_mask = (uint8_t)(shards - 1); meta->slot_shift = (uint8_t)__builtin_ctzll(data_size / shards); meta->per_slot_meta = per_slot_meta; - memset((uint8_t *)(meta + 1), 0, (size_t)shards * SBO_POOL_HDR); + meta->layout = shards > 1 ? SBO_LAYOUT_LOCK64 : 0; + memset((uint8_t *)(meta + 1), 0, header_base - sizeof(*meta)); uint8_t root_level = (uint8_t)(sbo_align_to(slots / shards).level - 1); @@ -728,7 +743,7 @@ void *sbo_data_ptr(void *metaptr, void *data_base, uint64_t obj_offset) { size_t sbo_meta_size(size_t data_size, size_t per_slot_pool) { uint8_t shards = sbo_shards_for_data(data_size); - return sizeof(sbo_meta_t) + (size_t)shards * (SBO_POOL_HDR + per_slot_pool); + return sbo_header_size(shards) + (size_t)shards * per_slot_pool; } #endif /* SLOTSBOXMALLOC_IMPLEMENTATION */