From: Eric Dumazet <eric.dumazet@gmail.com>
To: hadi@cyberus.ca
Cc: Changli Gao <xiaosuo@gmail.com>,
David Miller <davem@davemloft.net>,
therbert@google.com, shemminger@vyatta.com,
netdev@vger.kernel.org, Eilon Greenstein <eilong@broadcom.com>,
Brian Bloniarz <bmb@athenacr.com>
Subject: Re: [PATCH net-next-2.6] net: speedup udp receive path
Date: Sat, 01 May 2010 15:22:05 +0200 [thread overview]
Message-ID: <1272720125.2230.178.camel@edumazet-laptop> (raw)
In-Reply-To: <1272714966.14499.37.camel@bigi>
Le samedi 01 mai 2010 à 07:56 -0400, jamal a écrit :
>
> [1]i.e with this program rps was getting worse (it was much better
> before say net-next of apr14) and that non-rps has been getting better
> numbers since. The regression is real - but it is likely in another
> subsystem.
>
You must understand that the whole 'bench' is mostly governed by
scheduler artifacts. The regression you mention is probably a side
effect.
By slowing down one part, its possible to zap all calls to scheduler and
go maybe 300% faster (Because consumer threads can avoid 3/4 of the time
to schedule)
Reciprocally, optimizing one part of the network stack might make
threads hitting an empty queue, and need to call more often the
scheduler.
This is why some higly specialized programs never block/schedule and
perform busy loops instead.
next prev parent reply other threads:[~2010-05-01 13:22 UTC|newest]
Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-23 8:12 [PATCH v6] net: batch skb dequeueing from softnet input_pkt_queue Changli Gao
2010-04-23 9:27 ` Eric Dumazet
2010-04-23 22:02 ` jamal
2010-04-24 14:10 ` jamal
2010-04-26 14:03 ` Eric Dumazet
2010-04-26 14:55 ` Eric Dumazet
2010-04-26 21:06 ` jamal
[not found] ` <20100429174056.GA8044@gargoyle.fritz.box>
2010-04-29 17:56 ` Eric Dumazet
2010-04-29 18:10 ` OFT - reserving CPU's for networking Stephen Hemminger
2010-04-29 19:19 ` Thomas Gleixner
2010-04-29 20:02 ` Eric Dumazet
2010-04-30 18:15 ` Brian Bloniarz
2010-04-30 18:57 ` David Miller
2010-04-30 19:58 ` Thomas Gleixner
2010-04-30 21:01 ` Andi Kleen
2010-04-30 22:30 ` David Miller
2010-05-01 10:53 ` Andi Kleen
2010-05-01 22:03 ` David Miller
2010-05-01 22:58 ` Andi Kleen
2010-05-01 23:29 ` David Miller
2010-05-01 23:44 ` Ben Hutchings
2010-05-01 20:31 ` Martin Josefsson
2010-05-01 22:13 ` David Miller
[not found] ` <20100429182347.GA8512@gargoyle.fritz.box>
2010-04-29 19:12 ` [PATCH v6] net: batch skb dequeueing from softnet input_pkt_queue Eric Dumazet
[not found] ` <20100429214144.GA10663@gargoyle.fritz.box>
2010-04-30 5:25 ` Eric Dumazet
2010-04-30 23:38 ` David Miller
2010-05-01 11:00 ` Andi Kleen
2010-05-02 6:56 ` Eric Dumazet
2010-05-02 9:20 ` Andi Kleen
2010-05-02 10:54 ` Eric Dumazet
2010-05-02 14:13 ` Arjan van de Ven
2010-05-02 14:27 ` Eric Dumazet
2010-05-02 15:32 ` Eric Dumazet
2010-05-02 17:54 ` Arjan van de Ven
2010-05-02 19:22 ` Eric Dumazet
2010-05-02 22:06 ` Andi Kleen
2010-05-03 3:50 ` Arjan van de Ven
2010-05-03 5:17 ` Eric Dumazet
2010-05-03 10:22 ` Arjan van de Ven
2010-05-03 10:34 ` Andi Kleen
2010-05-03 14:09 ` Arjan van de Ven
2010-05-03 14:45 ` Brian Bloniarz
2010-05-04 1:10 ` Arjan van de Ven
2010-05-03 15:52 ` Andi Kleen
2010-05-04 1:11 ` Arjan van de Ven
2010-05-02 21:30 ` Andi Kleen
2010-05-02 15:46 ` Andi Kleen
2010-05-02 16:35 ` Eric Dumazet
2010-05-02 17:43 ` Arjan van de Ven
2010-05-02 17:47 ` Eric Dumazet
2010-05-02 21:25 ` Andi Kleen
2010-05-02 21:45 ` Eric Dumazet
2010-05-02 21:54 ` Andi Kleen
2010-05-02 22:08 ` Eric Dumazet
2010-05-03 20:15 ` jamal
2010-04-26 21:03 ` jamal
2010-04-23 10:26 ` Eric Dumazet
2010-04-27 22:08 ` David Miller
2010-04-27 22:18 ` [PATCH net-next-2.6] bnx2x: Remove two prefetch() Eric Dumazet
2010-04-27 22:19 ` David Miller
2010-04-28 13:14 ` Eilon Greenstein
2010-04-28 15:44 ` Eliezer Tamir
2010-04-28 16:53 ` David Miller
[not found] ` <w2ue8f3c3211004280842r9f2589e8qb8fd4b7933cd9756@mail.gmail.com>
2010-04-28 16:55 ` David Miller
2010-04-28 11:33 ` jamal
2010-04-28 12:33 ` Eric Dumazet
2010-04-28 12:36 ` jamal
2010-04-28 14:06 ` [PATCH net-next-2.6] net: speedup udp receive path Eric Dumazet
2010-04-28 14:19 ` Eric Dumazet
2010-04-28 14:34 ` Eric Dumazet
2010-04-28 21:36 ` David Miller
2010-04-28 22:22 ` [PATCH net-next-2.6] net: ip_queue_rcv_skb() helper Eric Dumazet
2010-04-28 22:39 ` David Miller
2010-04-28 23:44 ` [PATCH net-next-2.6] net: speedup udp receive path jamal
2010-04-29 0:00 ` jamal
2010-04-29 4:09 ` Eric Dumazet
2010-04-29 11:35 ` jamal
2010-04-29 12:12 ` Changli Gao
2010-04-29 12:45 ` Eric Dumazet
2010-04-29 13:17 ` jamal
2010-04-29 13:21 ` Eric Dumazet
2010-04-29 13:37 ` jamal
2010-04-29 13:49 ` Eric Dumazet
2010-04-29 13:56 ` jamal
2010-04-29 20:36 ` jamal
2010-04-29 21:01 ` [PATCH net-next-2.6] net: sock_def_readable() and friends RCU conversion Eric Dumazet
2010-04-30 13:55 ` Brian Bloniarz
2010-04-30 17:26 ` Eric Dumazet
2010-04-30 23:35 ` David Miller
2010-05-01 4:56 ` Eric Dumazet
2010-05-01 7:02 ` Eric Dumazet
2010-05-01 8:03 ` Eric Dumazet
2010-05-01 22:00 ` David Miller
2010-04-30 19:30 ` [PATCH net-next-2.6] net: speedup udp receive path jamal
2010-04-30 20:40 ` Eric Dumazet
2010-05-01 0:06 ` jamal
2010-05-01 5:57 ` Eric Dumazet
2010-05-01 6:14 ` Eric Dumazet
2010-05-01 10:24 ` Changli Gao
2010-05-01 10:47 ` Eric Dumazet
2010-05-01 11:29 ` jamal
2010-05-01 11:23 ` jamal
2010-05-01 11:42 ` Eric Dumazet
2010-05-01 11:56 ` jamal
2010-05-01 13:22 ` Eric Dumazet [this message]
2010-05-01 13:49 ` jamal
2010-05-03 20:10 ` jamal
2010-04-29 23:07 ` Changli Gao
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