| Message ID | 20241001231438.3855035-1-alexandre.ferrieux@orange.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9b8ca04854fd1253a58aeb1bd089c191cb5a074c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] ipv4: avoid quadratic behavior in FIB insertion of common address | expand |
On Wed, Oct 2, 2024 at 1:14 AM Alexandre Ferrieux <alexandre.ferrieux@gmail.com> wrote: > > 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> I guess we will have to use per-netns hash tables soon anyway.
From: Eric Dumazet <edumazet@google.com> Date: Wed, 2 Oct 2024 10:38:11 +0200 > On Wed, Oct 2, 2024 at 1:14 AM Alexandre Ferrieux > <alexandre.ferrieux@gmail.com> wrote: > > > > 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> > > I guess we will have to use per-netns hash tables soon anyway. Yes, it's on my stash :) Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Wed, 2 Oct 2024 01:14:38 +0200 you wrote: > 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> > --- > net/ipv4/fib_semantics.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) Here is the summary with links: - [net-next,v2] ipv4: avoid quadratic behavior in FIB insertion of common address https://git.kernel.org/netdev/net-next/c/9b8ca04854fd You are awesome, thank you!
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) {
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> --- net/ipv4/fib_semantics.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)