From e9bd0cca09d13ac2f08d25e195203e42d4ad1ce8 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 7 Sep 2022 18:10:18 -0700 Subject: tcp: Don't allocate tcp_death_row outside of struct netns_ipv4. We will soon introduce an optional per-netns ehash and access hash tables via net->ipv4.tcp_death_row->hashinfo instead of &tcp_hashinfo in most places. It could harm the fast path because dereferences of two fields in net and tcp_death_row might incur two extra cache line misses. To save one dereference, let's place tcp_death_row back in netns_ipv4 and fetch hashinfo via net->ipv4.tcp_death_row"."hashinfo. Note tcp_death_row was initially placed in netns_ipv4, and commit fbb8295248e1 ("tcp: allocate tcp_death_row outside of struct netns_ipv4") changed it to a pointer so that we can fire TIME_WAIT timers after freeing net. However, we don't do so after commit 04c494e68a13 ("Revert "tcp/dccp: get rid of inet_twsk_purge()""), so we need not define tcp_death_row as a pointer. Also, we move refcount_dec_and_test(&tw_refcount) from tcp_sk_exit() to tcp_sk_exit_batch() as a debug check. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski --- net/ipv4/inet_timewait_sock.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'net/ipv4/inet_timewait_sock.c') diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 47ccc343c9fb..71d3bb0abf6c 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -59,9 +59,7 @@ static void inet_twsk_kill(struct inet_timewait_sock *tw) inet_twsk_bind_unhash(tw, hashinfo); spin_unlock(&bhead->lock); - if (refcount_dec_and_test(&tw->tw_dr->tw_refcount)) - kfree(tw->tw_dr); - + refcount_dec(&tw->tw_dr->tw_refcount); inet_twsk_put(tw); } -- cgit v1.2.3