On 5/25/23 7:49 PM, Kuniyuki Iwashima wrote:
We may want to use rcu_access_pointer(sk->sk_reuseport_cb) in
each lookup_reuseport() instead of adding sk_state check ?
And if someone has a weird program that creates multiple listeners and
disable SO_REUSEPORT for a listener that hits first in lhash2, checking
sk_reuseport_cb might not work ?
I am also not sure what the correct expectation is if the application disable
SO_REUSEPORT in a sk after bind(). This is not something new or specific from
the current patch though.
I hope no one does such though, checking sk_reuseport
and sk_state could be better.
My previous comment on checking sk_state is to avoid the unnecessary
inet_ehashfn() for the TCP_ESTABLISHED sk. Checking sk_reuseport_cb could also
work since it should be NULL for established sk. However, not sure if it could
be another cacheline access. The udp one is checking the sk_state also:
"sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED".
