From: Tom Herbert <therbert@google.com>
To: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: David Miller <davem@davemloft.net>,
rick.jones2@hp.com, wsommerfeld@google.com,
daniel.baluta@gmail.com, netdev@vger.kernel.org
Subject: Re: SO_REUSEPORT - can it be done in kernel?
Date: Sun, 27 Feb 2011 19:45:55 -0800 [thread overview]
Message-ID: <AANLkTinxv4JC20YepcMvWi8SL_VTX2sXcRMydD62TT6x@mail.gmail.com> (raw)
In-Reply-To: <20110227110614.GA6246@gondor.apana.org.au>
> I disagree completely.
>
> This patch adds a user-space API that we will have to carry
> with us for perpetuity. I would only support this if we had
> no other way around the problem.
>
> If this does turn out to be mostly due to sendmsg contention
> then fixing it is going to be much simpler than making the UDP
> stack multiqueue capable.
>
That sounds promising, but receive side will still have problems.
There is lock contention on the queue as well as cache line bouncing
on the sock structures. Also multiple threads sleeping on same socket
typically leads to asymmetric load across the threads (and
degenerative cases where receiving thread is woken up and other
threads have already processed all the packets). TCP listener threads
suffer from these same problems.
Tom
> I'm working on this right now.
>
> Cheers,
> --
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
>
next prev parent reply other threads:[~2011-02-28 3:45 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-27 10:07 SO_REUSEPORT - can it be done in kernel? Daniel Baluta
2011-01-27 15:55 ` Bill Sommerfeld
2011-01-27 21:32 ` Tom Herbert
2011-02-25 12:56 ` Thomas Graf
2011-02-25 19:18 ` Rick Jones
2011-02-25 19:20 ` David Miller
2011-02-26 0:57 ` Herbert Xu
2011-02-26 2:12 ` David Miller
2011-02-26 2:48 ` Herbert Xu
2011-02-26 3:07 ` David Miller
2011-02-26 3:11 ` Herbert Xu
2011-02-26 7:31 ` Eric Dumazet
2011-02-26 7:46 ` David Miller
2011-02-27 11:02 ` Thomas Graf
2011-02-27 11:06 ` Herbert Xu
2011-02-28 3:45 ` Tom Herbert [this message]
2011-02-28 4:26 ` Herbert Xu
2011-02-28 11:36 ` Herbert Xu
2011-02-28 13:32 ` Eric Dumazet
2011-02-28 14:13 ` Herbert Xu
2011-02-28 14:22 ` Eric Dumazet
2011-02-28 14:25 ` Herbert Xu
2011-02-28 14:53 ` Eric Dumazet
2011-02-28 15:01 ` Thomas Graf
2011-02-28 14:13 ` Thomas Graf
2011-02-28 16:22 ` Eric Dumazet
2011-02-28 16:37 ` Thomas Graf
2011-02-28 17:07 ` Eric Dumazet
2011-03-01 10:19 ` Thomas Graf
2011-03-01 10:33 ` Eric Dumazet
2011-03-01 11:07 ` Thomas Graf
2011-03-01 11:13 ` Eric Dumazet
2011-03-01 11:27 ` Thomas Graf
2011-03-01 11:45 ` Eric Dumazet
2011-03-01 11:53 ` Herbert Xu
2011-03-01 12:32 ` Herbert Xu
2011-03-01 13:04 ` Eric Dumazet
2011-03-01 13:11 ` Herbert Xu
2011-03-01 13:03 ` Eric Dumazet
2011-03-01 13:18 ` Herbert Xu
2011-03-01 13:52 ` Eric Dumazet
2011-03-01 13:58 ` Herbert Xu
2011-03-01 16:31 ` Eric Dumazet
2011-03-02 0:23 ` Herbert Xu
2011-03-02 2:00 ` Eric Dumazet
2011-03-02 2:39 ` Herbert Xu
2011-03-02 2:56 ` Eric Dumazet
2011-03-02 3:09 ` Herbert Xu
2011-03-02 3:44 ` Eric Dumazet
2011-03-02 7:12 ` Tom Herbert
2011-03-02 7:31 ` Herbert Xu
2011-03-02 8:04 ` Eric Dumazet
2011-03-02 8:07 ` Herbert Xu
2011-03-02 8:24 ` Eric Dumazet
2011-03-01 12:01 ` Thomas Graf
2011-03-01 12:15 ` Herbert Xu
2011-03-01 13:27 ` Herbert Xu
2011-03-01 12:18 ` Thomas Graf
2011-03-01 12:19 ` Herbert Xu
2011-03-01 13:50 ` Thomas Graf
2011-03-01 14:06 ` Eric Dumazet
2011-03-01 14:22 ` Thomas Graf
2011-03-01 14:30 ` Thomas Graf
2011-03-01 14:52 ` Eric Dumazet
2011-03-01 15:07 ` Thomas Graf
2011-03-01 5:33 ` Eric Dumazet
2011-03-01 12:35 ` Herbert Xu
2011-03-01 12:36 ` [PATCH 3/5] inet: Add ip_make_skb and ip_finish_skb Herbert Xu
2011-03-01 12:36 ` [PATCH 2/5] inet: Remove explicit write references to sk/inet in ip_append_data Herbert Xu
2011-03-02 6:15 ` inet: Replace left-over references to inet->cork Herbert Xu
2011-03-02 7:01 ` David Miller
2011-03-01 12:36 ` [PATCH 1/5] inet: Remove unused sk_sndmsg_* from UFO Herbert Xu
2011-03-01 12:36 ` [PATCH 5/5] udp: Add lockless transmit path Herbert Xu
2011-03-01 12:36 ` [PATCH 4/5] udp: Switch to ip_finish_skb Herbert Xu
2011-03-01 16:43 ` SO_REUSEPORT - can it be done in kernel? Eric Dumazet
2011-03-01 20:36 ` David Miller
2011-02-28 11:41 ` [PATCH 2/5] net: Remove explicit write references to sk/inet in ip_append_data Herbert Xu
2011-03-01 5:31 ` Eric Dumazet
2011-02-28 11:41 ` [PATCH 1/5] net: Remove unused sk_sndmsg_* from UFO Herbert Xu
2011-03-01 5:31 ` Eric Dumazet
2011-02-28 11:41 ` [PATCH 3/5] inet: Add ip_make_skb and ip_send_skb Herbert Xu
2011-03-01 5:31 ` Eric Dumazet
2011-02-28 11:41 ` [PATCH 4/5] udp: Add lockless transmit path Herbert Xu
2011-02-28 11:41 ` Herbert Xu
2011-03-01 5:30 ` Eric Dumazet
2011-02-25 19:21 ` SO_REUSEPORT - can it be done in kernel? Eric Dumazet
2011-02-25 22:48 ` Thomas Graf
2011-02-25 23:15 ` Rick Jones
2011-02-25 19:51 ` Tom Herbert
2011-02-25 22:58 ` Thomas Graf
2011-02-25 23:33 ` Bill Sommerfeld
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