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author | Kent Overstreet <kent.overstreet@linux.dev> | 2022-12-05 10:24:19 -0500 |
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committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-22 17:09:53 -0400 |
commit | 80c33085783656617d0d07e1bc9fba70a592ce5c (patch) | |
tree | 2f2a6b43a3b6caab092c4f74df9f5a582e1a60b0 /fs/bcachefs/alloc_background.h | |
parent | 1b30ed5fd87828b5e29647510eefb18a363e4d19 (diff) | |
download | linux-80c33085783656617d0d07e1bc9fba70a592ce5c.tar.gz linux-80c33085783656617d0d07e1bc9fba70a592ce5c.tar.bz2 linux-80c33085783656617d0d07e1bc9fba70a592ce5c.zip |
bcachefs: Fragmentation LRU
Now that we have much more efficient updates to the LRU btree, this
patch adds a new LRU that indexes buckets by fragmentation.
This means copygc no longer has to scan every bucket to find buckets
that need to be evacuated.
Changes:
- A new field in bch_alloc_v4, fragmentation_lru - this corresponds to
the bucket's position in the fragmentation LRU. We add a new field
for this instead of calculating it as needed because we may make the
fragmentation LRU optional; this field indicates whether a bucket is
on the fragmentation LRU.
Also, zoned devices will introduce variable bucket sizes; explicitly
recording the LRU position will be safer for them.
- A new copygc path for using the fragmentation LRU instead of
scanning every bucket and building up an in-memory heap.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/alloc_background.h')
-rw-r--r-- | fs/bcachefs/alloc_background.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h index b3c2f1e0deb6..96ac8f396d46 100644 --- a/fs/bcachefs/alloc_background.h +++ b/fs/bcachefs/alloc_background.h @@ -64,11 +64,24 @@ static inline enum bch_data_type alloc_data_type(struct bch_alloc_v4 a, a.stripe, a, data_type); } -static inline u64 alloc_lru_idx(struct bch_alloc_v4 a) +static inline u64 alloc_lru_idx_read(struct bch_alloc_v4 a) { return a.data_type == BCH_DATA_cached ? a.io_time[READ] : 0; } +static inline u64 alloc_lru_idx_fragmentation(struct bch_alloc_v4 a, + struct bch_dev *ca) +{ + if (a.data_type != BCH_DATA_btree && + a.data_type != BCH_DATA_user) + return 0; + + if (a.dirty_sectors >= ca->mi.bucket_size) + return 0; + + return div_u64((u64) a.dirty_sectors * (1ULL << 31), ca->mi.bucket_size); +} + static inline u64 alloc_freespace_genbits(struct bch_alloc_v4 a) { return ((u64) alloc_gc_gen(a) >> 4) << 56; |