6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit 50e2907ef8bb52cf80ecde9eec5c4dac07177146 ]
TCP ehash table is often sparsely populated.
inet_twsk_purge() spends too much time calling cond_resched().
This patch can reduce time spent in inet_twsk_purge() by 20x.
Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Link: https://lore.kernel.org/r/20240327191206.508114-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 565d121b6998 ("tcp: prevent concurrent execution of tcp_sk_exit_batch") Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/inet_timewait_sock.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 757ae3a4e2f1a..55f60d1b46f2d 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -281,12 +281,17 @@ EXPORT_SYMBOL_GPL(__inet_twsk_schedule); /* Remove all non full sockets (TIME_WAIT and NEW_SYN_RECV) for dead netns */ void inet_twsk_purge(struct inet_hashinfo *hashinfo, int family) { + struct inet_ehash_bucket *head = &hashinfo->ehash[0]; + unsigned int ehash_mask = hashinfo->ehash_mask; struct hlist_nulls_node *node; unsigned int slot; struct sock *sk;
- for (slot = 0; slot <= hashinfo->ehash_mask; slot++) { - struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; + for (slot = 0; slot <= ehash_mask; slot++, head++) { + + if (hlist_nulls_empty(&head->chain)) + continue; + restart_rcu: cond_resched(); rcu_read_lock();