From: Eric Dumazet <eric.dumazet@gmail.com>
To: Martin KaFai Lau <kafai@fb.com>, netdev <netdev@vger.kernel.org>
Cc: "David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Kernel Team <kernel-team@fb.com>
Subject: Re: [PATCH net-next 3/4] inet: Add a 2nd listener hashtable (port+addr)
Date: Fri, 01 Dec 2017 09:26:46 -0800 [thread overview]
Message-ID: <1512149206.19682.37.camel@gmail.com> (raw)
In-Reply-To: <20171130232327.561108-4-kafai@fb.com>
On Thu, 2017-11-30 at 15:23 -0800, Martin KaFai Lau wrote:
> The current listener hashtable is hashed by port only.
> When a process is listening at many IP addresses with the same port
> (e.g.
> [IP1]:443, [IP2]:443... [IPN]:443), the inet[6]_lookup_listener()
> performance is degraded to a link list. It is prone to syn attack.
>
>
...
> diff --git a/include/net/inet_hashtables.h
> b/include/net/inet_hashtables.h
> index 4cce516c41ac..ebce55d694e7 100644
> --- a/include/net/inet_hashtables.h
> +++ b/include/net/inet_hashtables.h
> @@ -152,8 +152,19 @@ struct inet_hashinfo {
> */
> struct inet_listen_hashbucket listening_hash[INET_LHT
> ABLE_SIZE]
> ____cacheline_aligned_in_smp
> ;
> + struct inet_listen_hashbucket *lhash2;
> + unsigned int lhash2_mask;
> };
>
Please move these two fields before listening_hash[], to avoid adding
another cache line to "struct inet_hashinfo"
( We have a 16-byte hole there, so lets use it ;) )
next prev parent reply other threads:[~2017-12-01 17:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-30 23:23 [PATCH net-next 0/4] tcp: Add a 2nd listener hashtable (port+addr) Martin KaFai Lau
2017-11-30 23:23 ` [PATCH net-next 1/4] inet: Add a count to struct inet_listen_hashbucket Martin KaFai Lau
2017-12-01 17:19 ` Eric Dumazet
2017-11-30 23:23 ` [PATCH net-next 2/4] udp: Move udp[46]_portaddr_hash() to net/ip[v6].h Martin KaFai Lau
2017-12-01 17:22 ` Eric Dumazet
2017-11-30 23:23 ` [PATCH net-next 3/4] inet: Add a 2nd listener hashtable (port+addr) Martin KaFai Lau
2017-12-01 17:26 ` Eric Dumazet [this message]
2017-12-01 17:47 ` Martin KaFai Lau
2017-11-30 23:23 ` [PATCH net-next 4/4] tcp: Enable 2nd listener hashtable in TCP Martin KaFai Lau
2017-12-01 17:29 ` Eric Dumazet
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1512149206.19682.37.camel@gmail.com \
--to=eric.dumazet@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kafai@fb.com \
--cc=kernel-team@fb.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).