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| author | David S. Miller <davem@davemloft.net> | 2015-02-27 16:06:21 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-02-27 16:06:21 -0500 |
| commit | c0eebfa3233ef59109aa314ef19451d2156a2635 (patch) | |
| tree | 3e4d9c6941729846c3c55c7f256197321311b3aa /lib/rhashtable.c | |
| parent | 0d79a493e507437a2135e5ac1a447d4d503488d8 (diff) | |
| parent | 4c4b52d9b2df45e8216d3e30b5452e4a364d2cac (diff) | |
| download | linux-c0eebfa3233ef59109aa314ef19451d2156a2635.tar.bz2 | |
Merge branch 'rhashtable'
Daniel Borkmann says:
====================
rhashtable updates
As discussed, I'm sending out rhashtable fixups for -net.
I have a couple of more patches I was working on last week pending,
i.e. to get rid of ht->nelems and ht->shift atomic operations which
speed-up pure insertions/deletions, e.g. on my laptop I have 2 threads,
inserting 7M entries each, that will reduce insertion time from ~1,450 ms
to 865 ms (performance should even be better after removing the
grow/shrink indirections). I guess that however is rather something
for net-next.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib/rhashtable.c')
| -rw-r--r-- | lib/rhashtable.c | 58 |
1 files changed, 18 insertions, 40 deletions
diff --git a/lib/rhashtable.c b/lib/rhashtable.c index e3a04e4b3ec5..090641db4c0d 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -247,26 +247,24 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht, * @ht: hash table * @new_size: new table size */ -bool rht_grow_above_75(const struct rhashtable *ht, size_t new_size) +static bool rht_grow_above_75(const struct rhashtable *ht, size_t new_size) { /* Expand table when exceeding 75% load */ return atomic_read(&ht->nelems) > (new_size / 4 * 3) && - (ht->p.max_shift && atomic_read(&ht->shift) < ht->p.max_shift); + (!ht->p.max_shift || atomic_read(&ht->shift) < ht->p.max_shift); } -EXPORT_SYMBOL_GPL(rht_grow_above_75); /** * rht_shrink_below_30 - returns true if nelems < 0.3 * table-size * @ht: hash table * @new_size: new table size */ -bool rht_shrink_below_30(const struct rhashtable *ht, size_t new_size) +static bool rht_shrink_below_30(const struct rhashtable *ht, size_t new_size) { /* Shrink table beneath 30% load */ return atomic_read(&ht->nelems) < (new_size * 3 / 10) && (atomic_read(&ht->shift) > ht->p.min_shift); } -EXPORT_SYMBOL_GPL(rht_shrink_below_30); static void lock_buckets(struct bucket_table *new_tbl, struct bucket_table *old_tbl, unsigned int hash) @@ -528,40 +526,19 @@ static void rht_deferred_worker(struct work_struct *work) list_for_each_entry(walker, &ht->walkers, list) walker->resize = true; - if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size)) + if (rht_grow_above_75(ht, tbl->size)) rhashtable_expand(ht); - else if (ht->p.shrink_decision && ht->p.shrink_decision(ht, tbl->size)) + else if (rht_shrink_below_30(ht, tbl->size)) rhashtable_shrink(ht); - unlock: mutex_unlock(&ht->mutex); } -static void rhashtable_probe_expand(struct rhashtable *ht) -{ - const struct bucket_table *new_tbl = rht_dereference_rcu(ht->future_tbl, ht); - const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); - - /* Only adjust the table if no resizing is currently in progress. */ - if (tbl == new_tbl && ht->p.grow_decision && - ht->p.grow_decision(ht, tbl->size)) - schedule_work(&ht->run_work); -} - -static void rhashtable_probe_shrink(struct rhashtable *ht) -{ - const struct bucket_table *new_tbl = rht_dereference_rcu(ht->future_tbl, ht); - const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); - - /* Only adjust the table if no resizing is currently in progress. */ - if (tbl == new_tbl && ht->p.shrink_decision && - ht->p.shrink_decision(ht, tbl->size)) - schedule_work(&ht->run_work); -} - static void __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, - struct bucket_table *tbl, u32 hash) + struct bucket_table *tbl, + const struct bucket_table *old_tbl, u32 hash) { + bool no_resize_running = tbl == old_tbl; struct rhash_head *head; hash = rht_bucket_index(tbl, hash); @@ -577,8 +554,8 @@ static void __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, rcu_assign_pointer(tbl->buckets[hash], obj); atomic_inc(&ht->nelems); - - rhashtable_probe_expand(ht); + if (no_resize_running && rht_grow_above_75(ht, tbl->size)) + schedule_work(&ht->run_work); } /** @@ -608,7 +585,7 @@ void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj) hash = obj_raw_hashfn(ht, rht_obj(ht, obj)); lock_buckets(tbl, old_tbl, hash); - __rhashtable_insert(ht, obj, tbl, hash); + __rhashtable_insert(ht, obj, tbl, old_tbl, hash); unlock_buckets(tbl, old_tbl, hash); rcu_read_unlock(); @@ -690,8 +667,11 @@ found: unlock_buckets(new_tbl, old_tbl, new_hash); if (ret) { + bool no_resize_running = new_tbl == old_tbl; + atomic_dec(&ht->nelems); - rhashtable_probe_shrink(ht); + if (no_resize_running && rht_shrink_below_30(ht, new_tbl->size)) + schedule_work(&ht->run_work); } rcu_read_unlock(); @@ -861,7 +841,7 @@ bool rhashtable_lookup_compare_insert(struct rhashtable *ht, goto exit; } - __rhashtable_insert(ht, obj, new_tbl, new_hash); + __rhashtable_insert(ht, obj, new_tbl, old_tbl, new_hash); exit: unlock_buckets(new_tbl, old_tbl, new_hash); @@ -1123,8 +1103,7 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params) if (!ht->p.hash_rnd) get_random_bytes(&ht->p.hash_rnd, sizeof(ht->p.hash_rnd)); - if (ht->p.grow_decision || ht->p.shrink_decision) - INIT_WORK(&ht->run_work, rht_deferred_worker); + INIT_WORK(&ht->run_work, rht_deferred_worker); return 0; } @@ -1142,8 +1121,7 @@ void rhashtable_destroy(struct rhashtable *ht) { ht->being_destroyed = true; - if (ht->p.grow_decision || ht->p.shrink_decision) - cancel_work_sync(&ht->run_work); + cancel_work_sync(&ht->run_work); mutex_lock(&ht->mutex); bucket_table_free(rht_dereference(ht->tbl, ht)); |