| Message ID | 20240327191206.508114-1-edumazet@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 50e2907ef8bb52cf80ecde9eec5c4dac07177146 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] tcp/dccp: bypass empty buckets in inet_twsk_purge() | expand |
From: Eric Dumazet <edumazet@google.com> Date: Wed, 27 Mar 2024 19:12:06 +0000 > 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> Sounds good! Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> 1 nit below. > --- > 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 e8de45d34d56a507a4bdcceaccbd5707692b6c0a..b0cc07d9a568c5dc52bd29729862bcb03e5d595d 100644 > --- a/net/ipv4/inet_timewait_sock.c > +++ b/net/ipv4/inet_timewait_sock.c > @@ -266,12 +266,17 @@ 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++) { > + unnecessary blank link here. Thanks! > + if (hlist_nulls_empty(&head->chain)) > + continue; > + > restart_rcu: > cond_resched(); > rcu_read_lock(); > -- > 2.44.0.396.g6e790dbe36-goog >
On Wed, 27 Mar 2024 12:29:34 -0700 Kuniyuki Iwashima wrote: > > - for (slot = 0; slot <= hashinfo->ehash_mask; slot++) { > > - struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; > > + for (slot = 0; slot <= ehash_mask; slot++, head++) { > > + > > unnecessary blank link here. I've seen some other core kernel contributors add empty lines after for or if statements, so I think this is intentional. Not sure why the empty line helps, either, TBH, but we have been letting it slide so far.
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Wed, 27 Mar 2024 19:12:06 +0000 you wrote: > 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> > > [...] Here is the summary with links: - [net-next] tcp/dccp: bypass empty buckets in inet_twsk_purge() https://git.kernel.org/netdev/net-next/c/50e2907ef8bb You are awesome, thank you!
On Fri, Mar 29, 2024 at 4:06 PM Jakub Kicinski <kuba@kernel.org> wrote: > > On Wed, 27 Mar 2024 12:29:34 -0700 Kuniyuki Iwashima wrote: > > > - for (slot = 0; slot <= hashinfo->ehash_mask; slot++) { > > > - struct inet_ehash_bucket *head = &hashinfo->ehash[slot]; > > > + for (slot = 0; slot <= ehash_mask; slot++, head++) { > > > + > > > > unnecessary blank link here. > > I've seen some other core kernel contributors add empty lines after > for or if statements, so I think this is intentional. Not sure why > the empty line helps, either, TBH, but we have been letting it slide > so far. I will delete this extra line in the following patch, thanks !
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index e8de45d34d56a507a4bdcceaccbd5707692b6c0a..b0cc07d9a568c5dc52bd29729862bcb03e5d595d 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -266,12 +266,17 @@ 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();
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> --- net/ipv4/inet_timewait_sock.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)