From 6eba82248ef47fd478f940a418429e3ec95cb3db Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Thu, 13 Nov 2014 13:45:46 +0100 Subject: rhashtable: Drop gfp_flags arg in insert/remove functions Reallocation is only required for shrinking and expanding and both rely on a mutex for synchronization and callers of rhashtable_init() are in non atomic context. Therefore, no reason to continue passing allocation hints through the API. Instead, use GFP_KERNEL and add __GFP_NOWARN | __GFP_NORETRY to allow for silent fall back to vzalloc() without the OOM killer jumping in as pointed out by Eric Dumazet and Eric W. Biederman. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- lib/rhashtable.c | 41 +++++++++++++++++------------------------ 1 file changed, 17 insertions(+), 24 deletions(-) (limited to 'lib') diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 4b4b53bfa08b..25e4c213b08a 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -107,13 +107,13 @@ static u32 head_hashfn(const struct rhashtable *ht, return obj_hashfn(ht, rht_obj(ht, he), hsize); } -static struct bucket_table *bucket_table_alloc(size_t nbuckets, gfp_t flags) +static struct bucket_table *bucket_table_alloc(size_t nbuckets) { struct bucket_table *tbl; size_t size; size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]); - tbl = kzalloc(size, flags); + tbl = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); if (tbl == NULL) tbl = vzalloc(size); @@ -200,7 +200,6 @@ static void hashtable_chain_unzip(const struct rhashtable *ht, /** * rhashtable_expand - Expand hash table while allowing concurrent lookups * @ht: the hash table to expand - * @flags: allocation flags * * A secondary bucket array is allocated and the hash entries are migrated * while keeping them on both lists until the end of the RCU grace period. @@ -211,7 +210,7 @@ static void hashtable_chain_unzip(const struct rhashtable *ht, * The caller must ensure that no concurrent table mutations take place. * It is however valid to have concurrent lookups if they are RCU protected. */ -int rhashtable_expand(struct rhashtable *ht, gfp_t flags) +int rhashtable_expand(struct rhashtable *ht) { struct bucket_table *new_tbl, *old_tbl = rht_dereference(ht->tbl, ht); struct rhash_head *he; @@ -223,7 +222,7 @@ int rhashtable_expand(struct rhashtable *ht, gfp_t flags) if (ht->p.max_shift && ht->shift >= ht->p.max_shift) return 0; - new_tbl = bucket_table_alloc(old_tbl->size * 2, flags); + new_tbl = bucket_table_alloc(old_tbl->size * 2); if (new_tbl == NULL) return -ENOMEM; @@ -281,7 +280,6 @@ EXPORT_SYMBOL_GPL(rhashtable_expand); /** * rhashtable_shrink - Shrink hash table while allowing concurrent lookups * @ht: the hash table to shrink - * @flags: allocation flags * * This function may only be called in a context where it is safe to call * synchronize_rcu(), e.g. not within a rcu_read_lock() section. @@ -289,7 +287,7 @@ EXPORT_SYMBOL_GPL(rhashtable_expand); * The caller must ensure that no concurrent table mutations take place. * It is however valid to have concurrent lookups if they are RCU protected. */ -int rhashtable_shrink(struct rhashtable *ht, gfp_t flags) +int rhashtable_shrink(struct rhashtable *ht) { struct bucket_table *ntbl, *tbl = rht_dereference(ht->tbl, ht); struct rhash_head __rcu **pprev; @@ -300,7 +298,7 @@ int rhashtable_shrink(struct rhashtable *ht, gfp_t flags) if (ht->shift <= ht->p.min_shift) return 0; - ntbl = bucket_table_alloc(tbl->size / 2, flags); + ntbl = bucket_table_alloc(tbl->size / 2); if (ntbl == NULL) return -ENOMEM; @@ -341,7 +339,6 @@ EXPORT_SYMBOL_GPL(rhashtable_shrink); * rhashtable_insert - insert object into hash hash table * @ht: hash table * @obj: pointer to hash head inside object - * @flags: allocation flags (table expansion) * * Will automatically grow the table via rhashtable_expand() if the the * grow_decision function specified at rhashtable_init() returns true. @@ -349,8 +346,7 @@ EXPORT_SYMBOL_GPL(rhashtable_shrink); * The caller must ensure that no concurrent table mutations occur. It is * however valid to have concurrent lookups if they are RCU protected. */ -void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, - gfp_t flags) +void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj) { struct bucket_table *tbl = rht_dereference(ht->tbl, ht); u32 hash; @@ -363,7 +359,7 @@ void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj, ht->nelems++; if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size)) - rhashtable_expand(ht, flags); + rhashtable_expand(ht); } EXPORT_SYMBOL_GPL(rhashtable_insert); @@ -372,14 +368,13 @@ EXPORT_SYMBOL_GPL(rhashtable_insert); * @ht: hash table * @obj: pointer to hash head inside object * @pprev: pointer to previous element - * @flags: allocation flags (table expansion) * * Identical to rhashtable_remove() but caller is alreayd aware of the element * in front of the element to be deleted. This is in particular useful for * deletion when combined with walking or lookup. */ void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj, - struct rhash_head __rcu **pprev, gfp_t flags) + struct rhash_head __rcu **pprev) { struct bucket_table *tbl = rht_dereference(ht->tbl, ht); @@ -390,7 +385,7 @@ void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj, if (ht->p.shrink_decision && ht->p.shrink_decision(ht, tbl->size)) - rhashtable_shrink(ht, flags); + rhashtable_shrink(ht); } EXPORT_SYMBOL_GPL(rhashtable_remove_pprev); @@ -398,7 +393,6 @@ EXPORT_SYMBOL_GPL(rhashtable_remove_pprev); * rhashtable_remove - remove object from hash table * @ht: hash table * @obj: pointer to hash head inside object - * @flags: allocation flags (table expansion) * * Since the hash chain is single linked, the removal operation needs to * walk the bucket chain upon removal. The removal operation is thus @@ -410,8 +404,7 @@ EXPORT_SYMBOL_GPL(rhashtable_remove_pprev); * The caller must ensure that no concurrent table mutations occur. It is * however valid to have concurrent lookups if they are RCU protected. */ -bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj, - gfp_t flags) +bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj) { struct bucket_table *tbl = rht_dereference(ht->tbl, ht); struct rhash_head __rcu **pprev; @@ -429,7 +422,7 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj, continue; } - rhashtable_remove_pprev(ht, he, pprev, flags); + rhashtable_remove_pprev(ht, he, pprev); return true; } @@ -576,7 +569,7 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params) if (params->nelem_hint) size = rounded_hashtable_size(params); - tbl = bucket_table_alloc(size, GFP_KERNEL); + tbl = bucket_table_alloc(size); if (tbl == NULL) return -ENOMEM; @@ -713,7 +706,7 @@ static int __init test_rhashtable(struct rhashtable *ht) obj->ptr = TEST_PTR; obj->value = i * 2; - rhashtable_insert(ht, &obj->node, GFP_KERNEL); + rhashtable_insert(ht, &obj->node); } rcu_read_lock(); @@ -724,7 +717,7 @@ static int __init test_rhashtable(struct rhashtable *ht) for (i = 0; i < TEST_NEXPANDS; i++) { pr_info(" Table expansion iteration %u...\n", i); - rhashtable_expand(ht, GFP_KERNEL); + rhashtable_expand(ht); rcu_read_lock(); pr_info(" Verifying lookups...\n"); @@ -734,7 +727,7 @@ static int __init test_rhashtable(struct rhashtable *ht) for (i = 0; i < TEST_NEXPANDS; i++) { pr_info(" Table shrinkage iteration %u...\n", i); - rhashtable_shrink(ht, GFP_KERNEL); + rhashtable_shrink(ht); rcu_read_lock(); pr_info(" Verifying lookups...\n"); @@ -749,7 +742,7 @@ static int __init test_rhashtable(struct rhashtable *ht) obj = rhashtable_lookup(ht, &key); BUG_ON(!obj); - rhashtable_remove(ht, &obj->node, GFP_KERNEL); + rhashtable_remove(ht, &obj->node); kfree(obj); } -- cgit v1.2.3