From c2f6e16a6771eaefba6bb35f6803fe7217822d41 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Thu, 15 Aug 2024 13:02:55 -0400 Subject: [PATCH] bcachefs: Increase size of cuckoo hash table on too many rehashes Also, improve the calculation of the new table size, so that it can shrink when needed. Signed-off-by: Kent Overstreet --- fs/bcachefs/buckets_waiting_for_journal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/buckets_waiting_for_journal.c b/fs/bcachefs/buckets_waiting_for_journal.c index ec1b636ef78d..f70eb2127d32 100644 --- a/fs/bcachefs/buckets_waiting_for_journal.c +++ b/fs/bcachefs/buckets_waiting_for_journal.c @@ -93,7 +93,7 @@ int bch2_set_bucket_needs_journal_commit(struct buckets_waiting_for_journal *b, .dev_bucket = (u64) dev << 56 | bucket, .journal_seq = journal_seq, }; - size_t i, size, new_bits, nr_elements = 1, nr_rehashes = 0; + size_t i, size, new_bits, nr_elements = 1, nr_rehashes = 0, nr_rehashes_this_size = 0; int ret = 0; mutex_lock(&b->lock); @@ -106,7 +106,7 @@ int bch2_set_bucket_needs_journal_commit(struct buckets_waiting_for_journal *b, for (i = 0; i < size; i++) nr_elements += t->d[i].journal_seq > flushed_seq; - new_bits = t->bits + (nr_elements * 3 > size); + new_bits = ilog2(roundup_pow_of_two(nr_elements * 3)); n = kvmalloc(sizeof(*n) + (sizeof(n->d[0]) << new_bits), GFP_KERNEL); if (!n) { @@ -115,7 +115,14 @@ int bch2_set_bucket_needs_journal_commit(struct buckets_waiting_for_journal *b, } retry_rehash: + if (nr_rehashes_this_size == 3) { + new_bits++; + nr_rehashes_this_size = 0; + } + nr_rehashes++; + nr_rehashes_this_size++; + bucket_table_init(n, new_bits); tmp = new;