LCOV - code coverage report
Current view: top level - lib/ftl - ftl_nv_cache.h (source / functions) Hit Total Coverage
Test: ut_cov_unit.info Lines: 0 3 0.0 %
Date: 2024-07-10 13:30:00 Functions: 0 1 0.0 %

          Line data    Source code
       1             : /*   SPDX-License-Identifier: BSD-3-Clause
       2             :  *   Copyright 2023 Solidigm All Rights Reserved
       3             :  *   Copyright (C) 2022 Intel Corporation.
       4             :  *   All rights reserved.
       5             :  */
       6             : 
       7             : #ifndef FTL_NV_CACHE_H
       8             : #define FTL_NV_CACHE_H
       9             : 
      10             : #include "spdk/stdinc.h"
      11             : #include "spdk/crc32.h"
      12             : 
      13             : #include "ftl_io.h"
      14             : #include "ftl_utils.h"
      15             : #include "nvc/ftl_nvc_dev.h"
      16             : 
      17             : /*
      18             :  * FTL non volatile cache is divided into groups of blocks called chunks.
      19             :  * Size of each chunk is multiple of xfer size plus additional metadata.
      20             :  * For each block associated lba is stored in metadata. Cache space is
      21             :  * written chunk by chunk sequentially. When number of free chunks reaches
      22             :  * some threshold oldest chunks are moved from cache to backend storage to
      23             :  * create space for new user data.
      24             :  */
      25             : 
      26             : #define FTL_NVC_VERSION_0       0
      27             : #define FTL_NVC_VERSION_1       1
      28             : 
      29             : #define FTL_NVC_VERSION_CURRENT FTL_NVC_VERSION_1
      30             : 
      31             : #define FTL_NV_CACHE_NUM_COMPACTORS 8
      32             : 
      33             : /*
      34             :  * Parameters controlling nv cache write throttling.
      35             :  *
      36             :  * The write throttle limit value is calculated as follows:
      37             :  * limit = compaction_average_bw * (1.0 + modifier)
      38             :  *
      39             :  * The modifier depends on the number of free chunks vs the configured threshold. Its value is
      40             :  * zero if the number of free chunks is at the threshold, negative if below and positive if above.
      41             :  */
      42             : 
      43             : /* Interval in milliseconds between write throttle updates. */
      44             : #define FTL_NV_CACHE_THROTTLE_INTERVAL_MS       20
      45             : /* Throttle modifier proportional gain */
      46             : #define FTL_NV_CACHE_THROTTLE_MODIFIER_KP       20
      47             : /* Min and max modifier values */
      48             : #define FTL_NV_CACHE_THROTTLE_MODIFIER_MIN      -0.8
      49             : #define FTL_NV_CACHE_THROTTLE_MODIFIER_MAX      0.5
      50             : 
      51             : struct ftl_nvcache_restore;
      52             : typedef void (*ftl_nv_cache_restore_fn)(struct ftl_nvcache_restore *, int, void *cb_arg);
      53             : 
      54             : enum ftl_chunk_state {
      55             :         FTL_CHUNK_STATE_FREE,
      56             :         FTL_CHUNK_STATE_OPEN,
      57             :         FTL_CHUNK_STATE_CLOSED,
      58             :         FTL_CHUNK_STATE_MAX
      59             : };
      60             : 
      61             : struct ftl_nv_cache_chunk_md {
      62             :         /* Sequence id of writing */
      63             :         uint64_t seq_id;
      64             : 
      65             :         /* Sequence ID when chunk was closed */
      66             :         uint64_t close_seq_id;
      67             : 
      68             :         /* Current lba to write */
      69             :         uint32_t write_pointer;
      70             : 
      71             :         /* Number of blocks written */
      72             :         uint32_t blocks_written;
      73             : 
      74             :         /* Number of skipped block (case when IO size is greater than blocks left in chunk) */
      75             :         uint32_t blocks_skipped;
      76             : 
      77             :         /* Next block to be compacted */
      78             :         uint32_t read_pointer;
      79             : 
      80             :         /* Number of compacted (both valid and invalid) blocks */
      81             :         uint32_t blocks_compacted;
      82             : 
      83             :         /* Chunk state */
      84             :         enum ftl_chunk_state state;
      85             : 
      86             :         /* CRC32 checksum of the associated P2L map when chunk is in closed state */
      87             :         uint32_t p2l_map_checksum;
      88             : 
      89             :         /* Reserved */
      90             :         uint8_t reserved[4052];
      91             : } __attribute__((packed));
      92             : 
      93             : #define FTL_NV_CACHE_CHUNK_MD_SIZE sizeof(struct ftl_nv_cache_chunk_md)
      94             : SPDK_STATIC_ASSERT(FTL_NV_CACHE_CHUNK_MD_SIZE == FTL_BLOCK_SIZE,
      95             :                    "FTL NV Chunk metadata size is invalid");
      96             : 
      97             : struct ftl_nv_cache_chunk {
      98             :         struct ftl_nv_cache *nv_cache;
      99             : 
     100             :         struct ftl_nv_cache_chunk_md *md;
     101             : 
     102             :         /* Offset from start lba of the cache */
     103             :         uint64_t offset;
     104             : 
     105             :         /* P2L map */
     106             :         struct ftl_p2l_map p2l_map;
     107             : 
     108             :         /* Metadata request */
     109             :         struct ftl_basic_rq metadata_rq;
     110             : 
     111             :         TAILQ_ENTRY(ftl_nv_cache_chunk) entry;
     112             : 
     113             :         /* This flag is used to indicate chunk is used in recovery */
     114             :         bool recovery;
     115             : 
     116             :         /* Compaction start time */
     117             :         uint64_t compaction_start_tsc;
     118             : 
     119             :         /* Compaction duration */
     120             :         uint64_t compaction_length_tsc;
     121             : 
     122             :         /* For writing metadata */
     123             :         struct ftl_md_io_entry_ctx md_persist_entry_ctx;
     124             : };
     125             : 
     126             : struct ftl_nv_cache_compactor {
     127             :         struct ftl_nv_cache *nv_cache;
     128             :         struct ftl_rq *rq;
     129             :         TAILQ_ENTRY(ftl_nv_cache_compactor) entry;
     130             :         struct spdk_bdev_io_wait_entry bdev_io_wait;
     131             : };
     132             : 
     133             : struct ftl_nv_cache {
     134             :         /* Flag indicating halt request */
     135             :         bool halt;
     136             : 
     137             :         /* NV cache device descriptor */
     138             :         const struct ftl_nv_cache_device_desc *nvc_desc;
     139             : 
     140             :         /* Write buffer cache bdev */
     141             :         struct spdk_bdev_desc *bdev_desc;
     142             : 
     143             :         /* Persistent cache IO channel */
     144             :         struct spdk_io_channel *cache_ioch;
     145             : 
     146             :         /* Metadata pool */
     147             :         struct ftl_mempool *md_pool;
     148             : 
     149             :         /* P2L map memory pool */
     150             :         struct ftl_mempool *p2l_pool;
     151             : 
     152             :         /* Chunk md memory pool */
     153             :         struct ftl_mempool *chunk_md_pool;
     154             : 
     155             :         /* Chunk md memory pool for freeing chunks */
     156             :         struct ftl_mempool *free_chunk_md_pool;
     157             : 
     158             :         /* Block Metadata size */
     159             :         uint64_t md_size;
     160             : 
     161             :         /* NV cache metadata object handle */
     162             :         struct ftl_md *md;
     163             : 
     164             :         /* Number of blocks in chunk */
     165             :         uint64_t chunk_blocks;
     166             : 
     167             :         /* Number of blocks in tail md per chunk */
     168             :         uint64_t tail_md_chunk_blocks;
     169             : 
     170             :         /* Number of chunks */
     171             :         uint64_t chunk_count;
     172             : 
     173             :         /* Current processed chunk */
     174             :         struct ftl_nv_cache_chunk *chunk_current;
     175             : 
     176             :         /* Free chunks list */
     177             :         TAILQ_HEAD(, ftl_nv_cache_chunk) chunk_free_list;
     178             :         uint64_t chunk_free_count;
     179             : 
     180             :         /* Open chunks list */
     181             :         TAILQ_HEAD(, ftl_nv_cache_chunk) chunk_open_list;
     182             :         uint64_t chunk_open_count;
     183             : 
     184             :         /* Full chunks list */
     185             :         TAILQ_HEAD(, ftl_nv_cache_chunk) chunk_full_list;
     186             :         uint64_t chunk_full_count;
     187             : 
     188             :         /* Chunks being compacted */
     189             :         TAILQ_HEAD(, ftl_nv_cache_chunk) chunk_comp_list;
     190             :         uint64_t chunk_comp_count;
     191             : 
     192             :         /* Chunks being freed */
     193             :         TAILQ_HEAD(, ftl_nv_cache_chunk) needs_free_persist_list;
     194             :         uint64_t chunk_free_persist_count;
     195             : 
     196             :         TAILQ_HEAD(, ftl_nv_cache_compactor) compactor_list;
     197             :         uint64_t compaction_active_count;
     198             :         uint64_t chunk_compaction_threshold;
     199             : 
     200             :         struct ftl_nv_cache_chunk *chunks;
     201             : 
     202             :         uint64_t last_seq_id;
     203             : 
     204             :         uint64_t chunk_free_target;
     205             : 
     206             :         /* Simple moving average of recent compaction velocity values */
     207             :         double compaction_sma;
     208             : 
     209             : #define FTL_NV_CACHE_COMPACTION_SMA_N (FTL_NV_CACHE_NUM_COMPACTORS * 2)
     210             :         /* Circular buffer holding values for calculating compaction SMA */
     211             :         struct compaction_bw_stats {
     212             :                 double buf[FTL_NV_CACHE_COMPACTION_SMA_N];
     213             :                 ptrdiff_t first;
     214             :                 size_t count;
     215             :                 double sum;
     216             :         } compaction_recent_bw;
     217             : 
     218             :         struct {
     219             :                 uint64_t interval_tsc;
     220             :                 uint64_t start_tsc;
     221             :                 uint64_t blocks_submitted;
     222             :                 uint64_t blocks_submitted_limit;
     223             :         } throttle;
     224             : };
     225             : 
     226             : int ftl_nv_cache_init(struct spdk_ftl_dev *dev);
     227             : void ftl_nv_cache_deinit(struct spdk_ftl_dev *dev);
     228             : bool ftl_nv_cache_write(struct ftl_io *io);
     229             : void ftl_nv_cache_fill_md(struct ftl_io *io);
     230             : int ftl_nv_cache_read(struct ftl_io *io, ftl_addr addr, uint32_t num_blocks,
     231             :                       spdk_bdev_io_completion_cb cb, void *cb_arg);
     232             : bool ftl_nv_cache_throttle(struct spdk_ftl_dev *dev);
     233             : void ftl_nv_cache_process(struct spdk_ftl_dev *dev);
     234             : 
     235             : void ftl_chunk_map_set_lba(struct ftl_nv_cache_chunk *chunk,
     236             :                            uint64_t offset, uint64_t lba);
     237             : uint64_t ftl_chunk_map_get_lba(struct ftl_nv_cache_chunk *chunk, uint64_t offset);
     238             : 
     239             : void ftl_nv_cache_set_addr(struct spdk_ftl_dev *dev, uint64_t lba, ftl_addr addr);
     240             : 
     241             : int ftl_nv_cache_save_state(struct ftl_nv_cache *nv_cache);
     242             : 
     243             : int ftl_nv_cache_load_state(struct ftl_nv_cache *nv_cache);
     244             : 
     245             : void ftl_nv_cache_halt(struct ftl_nv_cache *nv_cache);
     246             : 
     247             : int ftl_nv_cache_chunks_busy(struct ftl_nv_cache *nv_cache);
     248             : 
     249             : static inline void
     250           0 : ftl_nv_cache_resume(struct ftl_nv_cache *nv_cache)
     251             : {
     252           0 :         nv_cache->halt = false;
     253           0 : }
     254             : 
     255             : bool ftl_nv_cache_is_halted(struct ftl_nv_cache *nv_cache);
     256             : 
     257             : size_t ftl_nv_cache_chunk_tail_md_num_blocks(const struct ftl_nv_cache *nv_cache);
     258             : 
     259             : uint64_t chunk_tail_md_offset(struct ftl_nv_cache *nv_cache);
     260             : /**
     261             :  * @brief Iterates over NV caches chunks and returns the max open and closed sequence id
     262             :  *
     263             :  * @param nv_cache FLT NV cache
     264             :  * @param[out] open_seq_id Max detected open sequence id
     265             :  * @param[out] close_seq_id Max detected close sequence id
     266             :  */
     267             : void ftl_nv_cache_get_max_seq_id(struct ftl_nv_cache *nv_cache, uint64_t *open_seq_id,
     268             :                                  uint64_t *close_seq_id);
     269             : 
     270             : void ftl_mngt_nv_cache_restore_chunk_state(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
     271             : 
     272             : void ftl_mngt_nv_cache_recover_open_chunk(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt);
     273             : 
     274             : typedef int (*ftl_chunk_md_cb)(struct ftl_nv_cache_chunk *chunk, void *cntx);
     275             : 
     276             : void ftl_mngt_nv_cache_restore_l2p(struct spdk_ftl_dev *dev, struct ftl_mngt_process *mngt,
     277             :                                    ftl_chunk_md_cb cb, void *cb_ctx);
     278             : 
     279             : struct ftl_nv_cache_chunk *ftl_nv_cache_get_chunk_from_addr(struct spdk_ftl_dev *dev,
     280             :                 ftl_addr addr);
     281             : 
     282             : uint64_t ftl_nv_cache_acquire_trim_seq_id(struct ftl_nv_cache *nv_cache);
     283             : 
     284             : #endif  /* FTL_NV_CACHE_H */

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