diff options
| author | Alexandre Ferrieux <alexandre.ferrieux@gmail.com> | 2024-10-02 01:14:38 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-10-03 16:15:30 -0700 |
| commit | 9b8ca04854fd1253a58aeb1bd089c191cb5a074c (patch) | |
| tree | 864c3637dd2d07fdbece66e62493470d1dfade9c /net/ipv4/fib_semantics.c | |
| parent | 35d8471e242d93ae5ef76580df2ebb92ce35e144 (diff) | |
ipv4: avoid quadratic behavior in FIB insertion of common address
Mix netns into all IPv4 FIB hashes to avoid massive collision when
inserting the same address in many netns.
Signed-off-by: Alexandre Ferrieux <alexandre.ferrieux@orange.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241001231438.3855035-1-alexandre.ferrieux@orange.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/fib_semantics.c')
| -rw-r--r-- | net/ipv4/fib_semantics.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index ba2df3d2ac15..1a847ba40458 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -347,11 +347,10 @@ static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope, return val; } -static unsigned int fib_info_hashfn_result(unsigned int val) +static unsigned int fib_info_hashfn_result(const struct net *net, + unsigned int val) { - unsigned int mask = (fib_info_hash_size - 1); - - return (val ^ (val >> 7) ^ (val >> 12)) & mask; + return hash_32(val ^ net_hash_mix(net), fib_info_hash_bits); } static inline unsigned int fib_info_hashfn(struct fib_info *fi) @@ -370,7 +369,7 @@ static inline unsigned int fib_info_hashfn(struct fib_info *fi) } endfor_nexthops(fi) } - return fib_info_hashfn_result(val); + return fib_info_hashfn_result(fi->fib_net, val); } /* no metrics, only nexthop id */ @@ -385,7 +384,7 @@ static struct fib_info *fib_find_info_nh(struct net *net, cfg->fc_protocol, cfg->fc_scope, (__force u32)cfg->fc_prefsrc, cfg->fc_priority); - hash = fib_info_hashfn_result(hash); + hash = fib_info_hashfn_result(net, hash); head = &fib_info_hash[hash]; hlist_for_each_entry(fi, head, fib_hash) { |