From 243f586920a86a04afe4d821cc310094f7dce102 Mon Sep 17 00:00:00 2001
From: "tom.leiming@gmail.com" <tom.leiming@gmail.com>
Date: Tue, 29 Dec 2015 22:40:26 +0800
Subject: [PATCH] bpf: hash: move select_bucket() out of htab's spinlock
The spinlock is just used for protecting the per-bucket
hlist, so it isn't needed for selecting bucket.
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
kernel/bpf/hashtab.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 2615388009a47..d857fcb3607b6 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -248,12 +248,11 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
memcpy(l_new->key + round_up(key_size, 8), value, map->value_size);
l_new->hash = htab_map_hash(l_new->key, key_size);
+ head = select_bucket(htab, l_new->hash);
/* bpf_map_update_elem() can be called in_irq() */
raw_spin_lock_irqsave(&htab->lock, flags);
- head = select_bucket(htab, l_new->hash);
-
l_old = lookup_elem_raw(head, l_new->hash, key, key_size);
if (!l_old && unlikely(atomic_read(&htab->count) >= map->max_entries)) {
@@ -310,11 +309,10 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
key_size = map->key_size;
hash = htab_map_hash(key, key_size);
+ head = select_bucket(htab, hash);
raw_spin_lock_irqsave(&htab->lock, flags);
- head = select_bucket(htab, hash);
-
l = lookup_elem_raw(head, hash, key, key_size);
if (l) {
--
2.39.5