From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/lib/rhashtable.c | 83 +++++++++++++++++++++++++++---------------------- 1 file changed, 45 insertions(+), 38 deletions(-) (limited to 'kernel/lib/rhashtable.c') diff --git a/kernel/lib/rhashtable.c b/kernel/lib/rhashtable.c index cf910e48f..51282f579 100644 --- a/kernel/lib/rhashtable.c +++ b/kernel/lib/rhashtable.c @@ -187,10 +187,7 @@ static int rhashtable_rehash_one(struct rhashtable *ht, unsigned int old_hash) head = rht_dereference_bucket(new_tbl->buckets[new_hash], new_tbl, new_hash); - if (rht_is_a_nulls(head)) - INIT_RHT_NULLS_HEAD(entry->next, ht, new_hash); - else - RCU_INIT_POINTER(entry->next, head); + RCU_INIT_POINTER(entry->next, head); rcu_assign_pointer(new_tbl->buckets[new_hash], entry); spin_unlock(new_bucket_lock); @@ -392,33 +389,31 @@ static bool rhashtable_check_elasticity(struct rhashtable *ht, return false; } -int rhashtable_insert_rehash(struct rhashtable *ht) +int rhashtable_insert_rehash(struct rhashtable *ht, + struct bucket_table *tbl) { struct bucket_table *old_tbl; struct bucket_table *new_tbl; - struct bucket_table *tbl; unsigned int size; int err; old_tbl = rht_dereference_rcu(ht->tbl, ht); - tbl = rhashtable_last_table(ht, old_tbl); size = tbl->size; + err = -EBUSY; + if (rht_grow_above_75(ht, tbl)) size *= 2; /* Do not schedule more than one rehash */ else if (old_tbl != tbl) - return -EBUSY; + goto fail; + + err = -ENOMEM; new_tbl = bucket_table_alloc(ht, size, GFP_ATOMIC); - if (new_tbl == NULL) { - /* Schedule async resize/rehash to try allocation - * non-atomic context. - */ - schedule_work(&ht->run_work); - return -ENOMEM; - } + if (new_tbl == NULL) + goto fail; err = rhashtable_rehash_attach(ht, tbl, new_tbl); if (err) { @@ -429,12 +424,24 @@ int rhashtable_insert_rehash(struct rhashtable *ht) schedule_work(&ht->run_work); return err; + +fail: + /* Do not fail the insert if someone else did a rehash. */ + if (likely(rcu_dereference_raw(tbl->future_tbl))) + return 0; + + /* Schedule async rehash to retry allocation in process context. */ + if (err == -ENOMEM) + schedule_work(&ht->run_work); + + return err; } EXPORT_SYMBOL_GPL(rhashtable_insert_rehash); -int rhashtable_insert_slow(struct rhashtable *ht, const void *key, - struct rhash_head *obj, - struct bucket_table *tbl) +struct bucket_table *rhashtable_insert_slow(struct rhashtable *ht, + const void *key, + struct rhash_head *obj, + struct bucket_table *tbl) { struct rhash_head *head; unsigned int hash; @@ -470,7 +477,12 @@ int rhashtable_insert_slow(struct rhashtable *ht, const void *key, exit: spin_unlock(rht_bucket_lock(tbl, hash)); - return err; + if (err == 0) + return NULL; + else if (err == -EAGAIN) + return tbl; + else + return ERR_PTR(err); } EXPORT_SYMBOL_GPL(rhashtable_insert_slow); @@ -506,10 +518,11 @@ int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter) if (!iter->walker) return -ENOMEM; - mutex_lock(&ht->mutex); - iter->walker->tbl = rht_dereference(ht->tbl, ht); + spin_lock(&ht->lock); + iter->walker->tbl = + rcu_dereference_protected(ht->tbl, lockdep_is_held(&ht->lock)); list_add(&iter->walker->list, &iter->walker->tbl->walkers); - mutex_unlock(&ht->mutex); + spin_unlock(&ht->lock); return 0; } @@ -523,10 +536,10 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_init); */ void rhashtable_walk_exit(struct rhashtable_iter *iter) { - mutex_lock(&iter->ht->mutex); + spin_lock(&iter->ht->lock); if (iter->walker->tbl) list_del(&iter->walker->list); - mutex_unlock(&iter->ht->mutex); + spin_unlock(&iter->ht->lock); kfree(iter->walker); } EXPORT_SYMBOL_GPL(rhashtable_walk_exit); @@ -550,14 +563,12 @@ int rhashtable_walk_start(struct rhashtable_iter *iter) { struct rhashtable *ht = iter->ht; - mutex_lock(&ht->mutex); + rcu_read_lock(); + spin_lock(&ht->lock); if (iter->walker->tbl) list_del(&iter->walker->list); - - rcu_read_lock(); - - mutex_unlock(&ht->mutex); + spin_unlock(&ht->lock); if (!iter->walker->tbl) { iter->walker->tbl = rht_dereference_rcu(ht->tbl, ht); @@ -585,7 +596,6 @@ void *rhashtable_walk_next(struct rhashtable_iter *iter) struct bucket_table *tbl = iter->walker->tbl; struct rhashtable *ht = iter->ht; struct rhash_head *p = iter->p; - void *obj = NULL; if (p) { p = rht_dereference_bucket_rcu(p->next, tbl, iter->slot); @@ -605,8 +615,7 @@ next: if (!rht_is_a_nulls(p)) { iter->skip++; iter->p = p; - obj = rht_obj(ht, p); - goto out; + return rht_obj(ht, p); } iter->skip = 0; @@ -624,9 +633,7 @@ next: return ERR_PTR(-EAGAIN); } -out: - - return obj; + return NULL; } EXPORT_SYMBOL_GPL(rhashtable_walk_next); @@ -730,9 +737,6 @@ int rhashtable_init(struct rhashtable *ht, if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT)) return -EINVAL; - if (params->nelem_hint) - size = rounded_hashtable_size(params); - memset(ht, 0, sizeof(*ht)); mutex_init(&ht->mutex); spin_lock_init(&ht->lock); @@ -752,6 +756,9 @@ int rhashtable_init(struct rhashtable *ht, ht->p.min_size = max(ht->p.min_size, HASH_MIN_SIZE); + if (params->nelem_hint) + size = rounded_hashtable_size(&ht->p); + /* The maximum (not average) chain length grows with the * size of the hash table, at a rate of (log N)/(log log N). * The value of 16 is selected so that even if the hash -- cgit 1.2.3-korg