Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753447AbbL2Okp (ORCPT ); Tue, 29 Dec 2015 09:40:45 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34973 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753202AbbL2Okk (ORCPT ); Tue, 29 Dec 2015 09:40:40 -0500 From: Ming Lei To: linux-kernel@vger.kernel.org, Alexei Starovoitov Cc: "David S. Miller" , netdev@vger.kernel.org, Daniel Borkmann , Ming Lei Subject: [PATCH v2 1/3] bpf: hash: use atomic count Date: Tue, 29 Dec 2015 22:40:25 +0800 Message-Id: <1451400027-28892-2-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1451400027-28892-1-git-send-email-tom.leiming@gmail.com> References: <1451400027-28892-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2399 Lines: 75 Preparing for removing global per-hashtable lock, so the counter need to be defined as aotmic_t first. Acked-by: Daniel Borkmann Signed-off-by: Ming Lei --- kernel/bpf/hashtab.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 34777b3..2615388 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -18,7 +18,7 @@ struct bpf_htab { struct bpf_map map; struct hlist_head *buckets; raw_spinlock_t lock; - u32 count; /* number of elements in this hashtable */ + atomic_t count; /* number of elements in this hashtable */ u32 n_buckets; /* number of hash buckets */ u32 elem_size; /* size of each element in bytes */ }; @@ -106,7 +106,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) INIT_HLIST_HEAD(&htab->buckets[i]); raw_spin_lock_init(&htab->lock); - htab->count = 0; + atomic_set(&htab->count, 0); return &htab->map; @@ -256,7 +256,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, l_old = lookup_elem_raw(head, l_new->hash, key, key_size); - if (!l_old && unlikely(htab->count >= map->max_entries)) { + if (!l_old && unlikely(atomic_read(&htab->count) >= map->max_entries)) { /* if elem with this 'key' doesn't exist and we've reached * max_entries limit, fail insertion of new elem */ @@ -284,7 +284,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, hlist_del_rcu(&l_old->hash_node); kfree_rcu(l_old, rcu); } else { - htab->count++; + atomic_inc(&htab->count); } raw_spin_unlock_irqrestore(&htab->lock, flags); @@ -319,7 +319,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key) if (l) { hlist_del_rcu(&l->hash_node); - htab->count--; + atomic_dec(&htab->count); kfree_rcu(l, rcu); ret = 0; } @@ -339,7 +339,7 @@ static void delete_all_elements(struct bpf_htab *htab) hlist_for_each_entry_safe(l, n, head, hash_node) { hlist_del_rcu(&l->hash_node); - htab->count--; + atomic_dec(&htab->count); kfree(l); } } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/