| Message ID | 20241215175629.1248773-1-edumazet@google.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | inetpeer: reduce false sharing and atomic operations | expand |
Hello: This series was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Sun, 15 Dec 2024 17:56:25 +0000 you wrote: > After commit 8c2bd38b95f7 ("icmp: change the order of rate limits"), > there is a risk that a host receiving packets from an unique > source targeting closed ports is using a common inet_peer structure > from many cpus. > > All these cpus have to acquire/release a refcount and update > the inet_peer timestamp (p->dtime) > > [...] Here is the summary with links: - [v2,net-next,1/4] inetpeer: remove create argument of inet_getpeer_v[46]() https://git.kernel.org/netdev/net-next/c/661cd8fc8e90 - [v2,net-next,2/4] inetpeer: remove create argument of inet_getpeer() https://git.kernel.org/netdev/net-next/c/7a596a50c4a4 - [v2,net-next,3/4] inetpeer: update inetpeer timestamp in inet_getpeer() https://git.kernel.org/netdev/net-next/c/50b362f21d6c - [v2,net-next,4/4] inetpeer: do not get a refcount in inet_getpeer() https://git.kernel.org/netdev/net-next/c/a853c609504e You are awesome, thank you!
After commit 8c2bd38b95f7 ("icmp: change the order of rate limits"), there is a risk that a host receiving packets from an unique source targeting closed ports is using a common inet_peer structure from many cpus. All these cpus have to acquire/release a refcount and update the inet_peer timestamp (p->dtime) Switch to pure RCU to avoid changing the refcount, and update p->dtime only once per jiffy. Tested: DUT : 128 cores, 32 hw rx queues. receiving 8,400,000 UDP packets per second, targeting closed ports. Before the series: - napi poll can not keep up, NIC drops 1,200,000 packets per second. - We use 20 % of cpu cycles After this series: - All packets are received (no more hw drops) - We use 12 % of cpu cycles. v2: addded Simon and Ido feedback from v1 v1: https://lore.kernel.org/netdev/20241213130212.1783302-1-edumazet@google.com/T/#mc6b32422714235f8608580a7dbf464c203300578 Eric Dumazet (4): inetpeer: remove create argument of inet_getpeer_v[46]() inetpeer: remove create argument of inet_getpeer() inetpeer: update inetpeer timestamp in inet_getpeer() inetpeer: do not get a refcount in inet_getpeer() include/net/inetpeer.h | 12 +++++------- net/ipv4/icmp.c | 9 ++++----- net/ipv4/inetpeer.c | 31 ++++++++----------------------- net/ipv4/ip_fragment.c | 15 ++++++++++----- net/ipv4/route.c | 17 +++++++++-------- net/ipv6/icmp.c | 6 +++--- net/ipv6/ip6_output.c | 6 +++--- net/ipv6/ndisc.c | 8 +++++--- 8 files changed, 47 insertions(+), 57 deletions(-)