diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-09-07 18:10:18 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-09-20 10:21:49 -0700 |
| commit | e9bd0cca09d13ac2f08d25e195203e42d4ad1ce8 (patch) | |
| tree | c098713403c2ed7e70d310348766a1acf9d5e374 /net/ipv4/sysctl_net_ipv4.c | |
| parent | 08eaef90403110e51861d93e8008a355af467bbe (diff) | |
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 <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/sysctl_net_ipv4.c')
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 5490c285668b..4d7c110c772f 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -530,10 +530,9 @@ static struct ctl_table ipv4_table[] = { }; static struct ctl_table ipv4_net_table[] = { - /* tcp_max_tw_buckets must be first in this table. */ { .procname = "tcp_max_tw_buckets", -/* .data = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets, */ + .data = &init_net.ipv4.tcp_death_row.sysctl_max_tw_buckets, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec @@ -1361,8 +1360,7 @@ static __net_init int ipv4_sysctl_init_net(struct net *net) if (!table) goto err_alloc; - /* skip first entry (sysctl_max_tw_buckets) */ - for (i = 1; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) { + for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++) { if (table[i].data) { /* Update the variables to point into * the current struct net @@ -1377,8 +1375,6 @@ static __net_init int ipv4_sysctl_init_net(struct net *net) } } - table[0].data = &net->ipv4.tcp_death_row->sysctl_max_tw_buckets; - net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table); if (!net->ipv4.ipv4_hdr) goto err_reg; |