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be9f4a44e7
tcp_v4_send_reset() and tcp_v4_send_ack() use a single socket per network namespace. This leads to bad behavior on multiqueue NICS, because many cpus contend for the socket lock and once socket lock is acquired, extra false sharing on various socket fields slow down the operations. To better resist to attacks, we use a percpu socket. Each cpu can run without contention, using appropriate memory (local node) Additional features : 1) We also mirror the queue_mapping of the incoming skb, so that answers use the same queue if possible. 2) Setting SOCK_USE_WRITE_QUEUE socket flag speedup sock_wfree() 3) We now limit the number of in-flight RST/ACK [1] packets per cpu, instead of per namespace, and we honor the sysctl_wmem_default limit dynamically. (Prior to this patch, sysctl_wmem_default value was copied at boot time, so any further change would not affect tcp_sock limit) [1] These packets are only generated when no socket was matched for the incoming packet. Reported-by: Bill Sommerfeld <wsommerfeld@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| conntrack.h | ||
| core.h | ||
| dccp.h | ||
| generic.h | ||
| hash.h | ||
| ipv4.h | ||
| ipv6.h | ||
| mib.h | ||
| packet.h | ||
| unix.h | ||
| x_tables.h | ||
| xfrm.h | ||