aboutsummaryrefslogtreecommitdiff
path: root/net/ipv6
diff options
context:
space:
mode:
authorKuniyuki Iwashima2022-09-07 18:10:21 -0700
committerJakub Kicinski2022-09-20 10:21:50 -0700
commitedc12f032a5a1633474db566878ce0012e7ca2f5 (patch)
treeb63f19cc61d23c9e24297a3471e68d7f37ced776 /net/ipv6
parent4461568aa4e565de2c336f4875ddf912f26da8a5 (diff)
tcp: Save unnecessary inet_twsk_purge() calls.
While destroying netns, we call inet_twsk_purge() in tcp_sk_exit_batch() and tcpv6_net_exit_batch() for AF_INET and AF_INET6. These commands trigger the kernel to walk through the potentially big ehash twice even though the netns has no TIME_WAIT sockets. # ip netns add test # ip netns del test or # unshare -n /bin/true >/dev/null When tw_refcount is 1, we need not call inet_twsk_purge() at least for the net. We can save such unneeded iterations if all netns in net_exit_list have no TIME_WAIT sockets. This change eliminates the tax by the additional unshare() described in the next patch to guarantee the per-netns ehash size. Tested: # mount -t debugfs none /sys/kernel/debug/ # echo cleanup_net > /sys/kernel/debug/tracing/set_ftrace_filter # echo inet_twsk_purge >> /sys/kernel/debug/tracing/set_ftrace_filter # echo function > /sys/kernel/debug/tracing/current_tracer # cat ./add_del_unshare.sh for i in `seq 1 40` do (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) & done wait; # ./add_del_unshare.sh Before the patch: # cat /sys/kernel/debug/tracing/trace_pipe kworker/u128:0-8 [031] ...1. 174.162765: cleanup_net <-process_one_work kworker/u128:0-8 [031] ...1. 174.240796: inet_twsk_purge <-cleanup_net kworker/u128:0-8 [032] ...1. 174.244759: inet_twsk_purge <-tcp_sk_exit_batch kworker/u128:0-8 [034] ...1. 174.290861: cleanup_net <-process_one_work kworker/u128:0-8 [039] ...1. 175.245027: inet_twsk_purge <-cleanup_net kworker/u128:0-8 [046] ...1. 175.290541: inet_twsk_purge <-tcp_sk_exit_batch kworker/u128:0-8 [037] ...1. 175.321046: cleanup_net <-process_one_work kworker/u128:0-8 [024] ...1. 175.941633: inet_twsk_purge <-cleanup_net kworker/u128:0-8 [025] ...1. 176.242539: inet_twsk_purge <-tcp_sk_exit_batch After: # cat /sys/kernel/debug/tracing/trace_pipe kworker/u128:0-8 [038] ...1. 428.116174: cleanup_net <-process_one_work kworker/u128:0-8 [038] ...1. 428.262532: cleanup_net <-process_one_work kworker/u128:0-8 [030] ...1. 429.292645: cleanup_net <-process_one_work Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/tcp_ipv6.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index f9ed47eb9b93..06beed4e23bf 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2229,7 +2229,7 @@ static void __net_exit tcpv6_net_exit(struct net *net)
static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
{
- inet_twsk_purge(&tcp_hashinfo, AF_INET6);
+ tcp_twsk_purge(net_exit_list, AF_INET6);
}
static struct pernet_operations tcpv6_net_ops = {