tcp/dccp: bypass empty buckets in inet_twsk_purge()

[ 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>
This commit is contained in:
Eric Dumazet 2024-03-27 19:12:06 +00:00 committed by Greg Kroah-Hartman
parent 0322502538
commit 9624febd69
1 changed files with 7 additions and 2 deletions

View File

@ -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();