| Message ID | 20220512000546.188616-1-kafai@fb.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | net: inet: Retire port only listening_hash | expand |
On Wed, May 11, 2022 at 5:05 PM Martin KaFai Lau <kafai@fb.com> wrote: > > This series is to retire the port only listening_hash. > > The listen sk is currently stored in two hash tables, > listening_hash (hashed by port) and lhash2 (hashed by port and address). > > After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") > and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), > the TCP-SYN lookup fast path does not use listening_hash. > > The commit 05c0b35709c5 ("tcp: seq_file: Replace listening_hash with lhash2") > also moved the seq_file (/proc/net/tcp) iteration usage from > listening_hash to lhash2. > > There are still a few listening_hash usages left. > One of them is inet_reuseport_add_sock() which uses the listening_hash > to search a listen sk during the listen() system call. This turns > out to be very slow on use cases that listen on many different > VIPs at a popular port (e.g. 443). [ On top of the slowness in > adding to the tail in the IPv6 case ]. A latter patch has a > selftest to demonstrate this case. > > This series takes this chance to move all remaining listening_hash > usages to lhash2 and then retire listening_hash. > > Martin KaFai Lau (4): > net: inet: Remove count from inet_listen_hashbucket > net: inet: Open code inet_hash2 and inet_unhash2 > net: inet: Retire port only listening_hash > net: selftests: Stress reuseport listen > Nice patches, thanks Martin. Reviewed-by: Eric Dumazet <edumazet@google.com>
Hello: This series was applied to netdev/net-next.git (master) by Jakub Kicinski <kuba@kernel.org>: On Wed, 11 May 2022 17:05:46 -0700 you wrote: > This series is to retire the port only listening_hash. > > The listen sk is currently stored in two hash tables, > listening_hash (hashed by port) and lhash2 (hashed by port and address). > > After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") > and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), > the TCP-SYN lookup fast path does not use listening_hash. > > [...] Here is the summary with links: - [net-next,1/4] net: inet: Remove count from inet_listen_hashbucket https://git.kernel.org/netdev/net-next/c/8ea1eebb49a2 - [net-next,2/4] net: inet: Open code inet_hash2 and inet_unhash2 https://git.kernel.org/netdev/net-next/c/e8d0059000b2 - [net-next,3/4] net: inet: Retire port only listening_hash https://git.kernel.org/netdev/net-next/c/cae3873c5b3a - [net-next,4/4] net: selftests: Stress reuseport listen https://git.kernel.org/netdev/net-next/c/ec8cb4f617a2 You are awesome, thank you!
This series is to retire the port only listening_hash. The listen sk is currently stored in two hash tables, listening_hash (hashed by port) and lhash2 (hashed by port and address). After commit 0ee58dad5b06 ("net: tcp6: prefer listeners bound to an address") and commit d9fbc7f6431f ("net: tcp: prefer listeners bound to an address"), the TCP-SYN lookup fast path does not use listening_hash. The commit 05c0b35709c5 ("tcp: seq_file: Replace listening_hash with lhash2") also moved the seq_file (/proc/net/tcp) iteration usage from listening_hash to lhash2. There are still a few listening_hash usages left. One of them is inet_reuseport_add_sock() which uses the listening_hash to search a listen sk during the listen() system call. This turns out to be very slow on use cases that listen on many different VIPs at a popular port (e.g. 443). [ On top of the slowness in adding to the tail in the IPv6 case ]. A latter patch has a selftest to demonstrate this case. This series takes this chance to move all remaining listening_hash usages to lhash2 and then retire listening_hash. Martin KaFai Lau (4): net: inet: Remove count from inet_listen_hashbucket net: inet: Open code inet_hash2 and inet_unhash2 net: inet: Retire port only listening_hash net: selftests: Stress reuseport listen include/net/inet_connection_sock.h | 2 - include/net/inet_hashtables.h | 42 +------ net/dccp/proto.c | 1 - net/ipv4/inet_diag.c | 5 +- net/ipv4/inet_hashtables.c | 119 +++++------------- net/ipv4/tcp.c | 1 - net/ipv4/tcp_ipv4.c | 21 ++-- net/ipv6/inet6_hashtables.c | 5 +- net/mptcp/mptcp_diag.c | 4 +- tools/testing/selftests/net/Makefile | 2 + .../selftests/net/stress_reuseport_listen.c | 105 ++++++++++++++++ .../selftests/net/stress_reuseport_listen.sh | 25 ++++ 12 files changed, 180 insertions(+), 152 deletions(-) create mode 100644 tools/testing/selftests/net/stress_reuseport_listen.c create mode 100755 tools/testing/selftests/net/stress_reuseport_listen.sh