diff options
author | Daniel Hill <daniel@gluo.nz> | 2022-07-14 11:33:09 +0300 |
---|---|---|
committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-23 00:09:35 +0300 |
commit | c807ca95a6e20bedbbb84287bc7087c2b2b775de (patch) | |
tree | 0add067029709ede728fd48ca3761325fe1cd8fc /fs/bcachefs | |
parent | 25055c690f9ab3d4fb72b8a07323bf952c2682dc (diff) | |
download | linux-c807ca95a6e20bedbbb84287bc7087c2b2b775de.tar.xz |
bcachefs: added lock held time stats
We now record the length of time btree locks are held and expose this in debugfs.
Enabled via CONFIG_BCACHEFS_LOCK_TIME_STATS.
Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs')
-rw-r--r-- | fs/bcachefs/Kconfig | 6 | ||||
-rw-r--r-- | fs/bcachefs/bcachefs.h | 9 | ||||
-rw-r--r-- | fs/bcachefs/btree_iter.c | 19 | ||||
-rw-r--r-- | fs/bcachefs/btree_key_cache.c | 4 | ||||
-rw-r--r-- | fs/bcachefs/btree_locking.h | 44 | ||||
-rw-r--r-- | fs/bcachefs/btree_types.h | 4 | ||||
-rw-r--r-- | fs/bcachefs/debug.c | 74 |
7 files changed, 145 insertions, 15 deletions
diff --git a/fs/bcachefs/Kconfig b/fs/bcachefs/Kconfig index d2eb65e9032b..7ae85900e5b4 100644 --- a/fs/bcachefs/Kconfig +++ b/fs/bcachefs/Kconfig @@ -59,6 +59,12 @@ config BCACHEFS_TESTS help Include some unit and performance tests for the core btree code +config BCACHEFS_LOCK_TIME_STATS + bool "bcachefs lock time statistics" + depends on BCACHEFS_FS + help + Expose statistics for how long we held a lock in debugfs + config BCACHEFS_NO_LATENCY_ACCT bool "disable latency accounting and time stats" depends on BCACHEFS_FS diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h index 7020eee5de21..9cd6f840b71a 100644 --- a/fs/bcachefs/bcachefs.h +++ b/fs/bcachefs/bcachefs.h @@ -319,6 +319,8 @@ BCH_DEBUG_PARAMS_DEBUG() #undef BCH_DEBUG_PARAM #endif +#define BCH_LOCK_TIME_NR 128 + #define BCH_TIME_STATS() \ x(btree_node_mem_alloc) \ x(btree_node_split) \ @@ -527,6 +529,11 @@ struct btree_debug { unsigned id; }; +struct lock_held_stats { + struct bch2_time_stats times[BCH_LOCK_TIME_NR]; + const char *names[BCH_LOCK_TIME_NR]; +}; + struct bch_fs_pcpu { u64 sectors_available; }; @@ -920,6 +927,8 @@ mempool_t bio_bounce_pages; bool promote_whole_extents; struct bch2_time_stats times[BCH_TIME_STAT_NR]; + + struct lock_held_stats lock_held_stats; }; static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages) diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c index d708bf32d408..30958cbb9532 100644 --- a/fs/bcachefs/btree_iter.c +++ b/fs/bcachefs/btree_iter.c @@ -177,7 +177,7 @@ bool __bch2_btree_node_relock(struct btree_trans *trans, if (six_relock_type(&b->c.lock, want, path->l[level].lock_seq) || (btree_node_lock_seq_matches(path, b, level) && btree_node_lock_increment(trans, b, level, want))) { - mark_btree_node_locked(path, level, want); + mark_btree_node_locked(trans, path, level, want); return true; } fail: @@ -230,7 +230,7 @@ bool bch2_btree_node_upgrade(struct btree_trans *trans, return false; success: - mark_btree_node_intent_locked(path, level); + mark_btree_node_intent_locked(trans, path, level); return true; } @@ -1161,7 +1161,7 @@ void bch2_trans_node_add(struct btree_trans *trans, struct btree *b) t != BTREE_NODE_UNLOCKED) { btree_node_unlock(trans, path, b->c.level); six_lock_increment(&b->c.lock, (enum six_lock_type) t); - mark_btree_node_locked(path, b->c.level, (enum six_lock_type) t); + mark_btree_node_locked(trans, path, b->c.level, (enum six_lock_type) t); } btree_path_level_init(trans, path, b); @@ -1238,7 +1238,7 @@ static inline int btree_path_lock_root(struct btree_trans *trans, for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++) path->l[i].b = NULL; - mark_btree_node_locked(path, path->level, lock_type); + mark_btree_node_locked(trans, path, path->level, lock_type); btree_path_level_init(trans, path, b); return 0; } @@ -1402,7 +1402,7 @@ static __always_inline int btree_path_down(struct btree_trans *trans, if (unlikely(ret)) goto err; - mark_btree_node_locked(path, level, lock_type); + mark_btree_node_locked(trans, path, level, lock_type); btree_path_level_init(trans, path, b); if (likely(!trans->journal_replay_not_finished && @@ -3273,6 +3273,15 @@ void __bch2_trans_init(struct btree_trans *trans, struct bch_fs *c, trans->journal_replay_not_finished = !test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags); + while (c->lock_held_stats.names[trans->lock_name_idx] != fn + && c->lock_held_stats.names[trans->lock_name_idx] != 0) + trans->lock_name_idx++; + + if (trans->lock_name_idx >= BCH_LOCK_TIME_NR) + pr_warn_once("lock_times array not big enough!"); + else + c->lock_held_stats.names[trans->lock_name_idx] = fn; + bch2_trans_alloc_paths(trans, c); if (expected_mem_bytes) { diff --git a/fs/bcachefs/btree_key_cache.c b/fs/bcachefs/btree_key_cache.c index baf1f25b91ca..e5a29240bbcc 100644 --- a/fs/bcachefs/btree_key_cache.c +++ b/fs/bcachefs/btree_key_cache.c @@ -382,7 +382,7 @@ retry: if (!ck) goto retry; - mark_btree_node_locked(path, 0, SIX_LOCK_intent); + mark_btree_node_locked(trans, path, 0, SIX_LOCK_intent); path->locks_want = 1; } else { enum six_lock_type lock_want = __btree_lock_want(path, 0); @@ -403,7 +403,7 @@ retry: goto retry; } - mark_btree_node_locked(path, 0, lock_want); + mark_btree_node_locked(trans, path, 0, lock_want); } path->l[0].lock_seq = ck->c.lock.state.seq; diff --git a/fs/bcachefs/btree_locking.h b/fs/bcachefs/btree_locking.h index 230f376993ae..b8708466c4e3 100644 --- a/fs/bcachefs/btree_locking.h +++ b/fs/bcachefs/btree_locking.h @@ -57,7 +57,8 @@ static inline void mark_btree_node_unlocked(struct btree_path *path, path->nodes_intent_locked &= ~(1 << level); } -static inline void mark_btree_node_locked(struct btree_path *path, +static inline void mark_btree_node_locked_noreset(struct btree_trans *trans, + struct btree_path *path, unsigned level, enum six_lock_type type) { @@ -69,10 +70,22 @@ static inline void mark_btree_node_locked(struct btree_path *path, path->nodes_intent_locked |= type << level; } -static inline void mark_btree_node_intent_locked(struct btree_path *path, +static inline void mark_btree_node_locked(struct btree_trans *trans, + struct btree_path *path, + unsigned level, + enum six_lock_type type) +{ + mark_btree_node_locked_noreset(trans, path, level, type); +#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS + path->l[level].lock_taken_time = ktime_get_ns(); +#endif +} + +static inline void mark_btree_node_intent_locked(struct btree_trans *trans, + struct btree_path *path, unsigned level) { - mark_btree_node_locked(path, level, SIX_LOCK_intent); + mark_btree_node_locked_noreset(trans, path, level, SIX_LOCK_intent); } static inline enum six_lock_type __btree_lock_want(struct btree_path *path, int level) @@ -101,8 +114,18 @@ static inline void btree_node_unlock(struct btree_trans *trans, EBUG_ON(level >= BTREE_MAX_DEPTH); - if (lock_type != BTREE_NODE_UNLOCKED) + if (lock_type != BTREE_NODE_UNLOCKED) { six_unlock_type(&path->l[level].b->c.lock, lock_type); +#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS + if (trans->lock_name_idx < BCH_LOCK_TIME_NR) { + struct bch_fs *c = trans->c; + + __bch2_time_stats_update(&c->lock_held_stats.times[trans->lock_name_idx], + path->l[level].lock_taken_time, + ktime_get_ns()); + } +#endif + } mark_btree_node_unlocked(path, level); } @@ -196,10 +219,17 @@ static inline bool btree_node_lock(struct btree_trans *trans, EBUG_ON(level >= BTREE_MAX_DEPTH); EBUG_ON(!(trans->paths_allocated & (1ULL << path->idx))); - return likely(six_trylock_type(&b->c.lock, type)) || + if (likely(six_trylock_type(&b->c.lock, type)) || btree_node_lock_increment(trans, b, level, type) || __bch2_btree_node_lock(trans, path, b, pos, level, type, - should_sleep_fn, p, ip); + should_sleep_fn, p, ip)) { +#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS + path->l[b->c.level].lock_taken_time = ktime_get_ns(); +#endif + return true; + } else { + return false; + } } bool __bch2_btree_node_relock(struct btree_trans *, struct btree_path *, unsigned); @@ -252,5 +282,3 @@ static inline void bch2_btree_node_lock_write(struct btree_trans *trans, } #endif /* _BCACHEFS_BTREE_LOCKING_H */ - - diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h index b184ec512499..8cf3ef749020 100644 --- a/fs/bcachefs/btree_types.h +++ b/fs/bcachefs/btree_types.h @@ -251,6 +251,9 @@ struct btree_path { struct btree *b; struct btree_node_iter iter; u32 lock_seq; +#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS + u64 lock_taken_time; +#endif } l[BTREE_MAX_DEPTH]; #ifdef CONFIG_BCACHEFS_DEBUG unsigned long ip_allocated; @@ -436,6 +439,7 @@ struct btree_trans { unsigned journal_u64s; unsigned journal_preres_u64s; struct replicas_delta_list *fs_usage_deltas; + int lock_name_idx; }; #define BTREE_FLAGS() \ diff --git a/fs/bcachefs/debug.c b/fs/bcachefs/debug.c index 0f25b75e3de7..45f5229f20eb 100644 --- a/fs/bcachefs/debug.c +++ b/fs/bcachefs/debug.c @@ -638,6 +638,75 @@ static const struct file_operations journal_pins_ops = { .read = bch2_journal_pins_read, }; +static int lock_held_stats_open(struct inode *inode, struct file *file) +{ + struct bch_fs *c = inode->i_private; + struct dump_iter *i; + + i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL); + + if (!i) + return -ENOMEM; + + i->iter = 0; + i->c = c; + i->buf = PRINTBUF; + file->private_data = i; + + return 0; +} + +static int lock_held_stats_release(struct inode *inode, struct file *file) +{ + struct dump_iter *i = file->private_data; + + printbuf_exit(&i->buf); + kfree(i); + + return 0; +} + +static ssize_t lock_held_stats_read(struct file *file, char __user *buf, + size_t size, loff_t *ppos) +{ + struct dump_iter *i = file->private_data; + struct lock_held_stats *lhs = &i->c->lock_held_stats; + int err; + + i->ubuf = buf; + i->size = size; + i->ret = 0; + + while (lhs->names[i->iter] != 0 && i->iter < BCH_LOCK_TIME_NR) { + err = flush_buf(i); + if (err) + return err; + + if (!i->size) + break; + + prt_printf(&i->buf, "%s:", lhs->names[i->iter]); + prt_newline(&i->buf); + printbuf_indent_add(&i->buf, 8); + bch2_time_stats_to_text(&i->buf, &lhs->times[i->iter]); + printbuf_indent_sub(&i->buf, 8); + prt_newline(&i->buf); + i->iter++; + } + + if (i->buf.allocation_failure) + return -ENOMEM; + + return i->ret; +} + +static const struct file_operations lock_held_stats_op = { + .owner = THIS_MODULE, + .open = lock_held_stats_open, + .release = lock_held_stats_release, + .read = lock_held_stats_read, +}; + void bch2_fs_debug_exit(struct bch_fs *c) { if (!IS_ERR_OR_NULL(c->fs_debug_dir)) @@ -668,6 +737,11 @@ void bch2_fs_debug_init(struct bch_fs *c) debugfs_create_file("journal_pins", 0400, c->fs_debug_dir, c->btree_debug, &journal_pins_ops); + if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) { + debugfs_create_file("lock_held_stats", 0400, c->fs_debug_dir, + c, &lock_held_stats_op); + } + c->btree_debug_dir = debugfs_create_dir("btrees", c->fs_debug_dir); if (IS_ERR_OR_NULL(c->btree_debug_dir)) return; |