From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
hans.schillstrom@ericsson.com, subramanian.vijay@gmail.com,
dave.taht@gmail.com, netdev@vger.kernel.org,
ncardwell@google.com, therbert@google.com, mph@hoth.dk
Subject: Re: [PATCH v2 net-next] tcp: avoid tx starvation by SYNACK packets
Date: Wed, 27 Jun 2012 10:21:15 +0200 [thread overview]
Message-ID: <1340785275.2028.151.camel@localhost> (raw)
In-Reply-To: <1340784137.26242.5.camel@edumazet-glaptop>
On Wed, 2012-06-27 at 10:02 +0200, Eric Dumazet wrote:
> On Wed, 2012-06-27 at 09:54 +0200, Jesper Dangaard Brouer wrote:
>
> > Well, that would lead to parallel SYN processing, wouldn't it?
>
> I think we already discussed of the current issues of current code.
>
> Telling people to spread SYN to several cpus is a good way to have a
> freeze in case of synflood, because 15 cpus are busy looping while one
> is doing progress.
Yes, that was also what I experienced (contention on spinlock), and then
tried to address it with my parallel SYN cookie patches, and it worked
amazing well...
> Thats why Intel felt the need of a hardware filter to direct all SYN
> packets on a single queue.
It works because we have a spinlock problem in the code... Perhaps, they
did it, because we have have locking/contention problem, not the other
way around ;-) How about fixing the code instead? ;-)))
next prev parent reply other threads:[~2012-06-27 8:21 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-31 21:56 [PATCH net-next] tcp: avoid tx starvation by SYNACK packets Eric Dumazet
2012-05-31 23:03 ` David Miller
2012-06-01 4:48 ` Eric Dumazet
2012-06-01 17:46 ` David Miller
2012-06-01 7:00 ` [PATCH] tcp: do not create inetpeer on SYNACK message Eric Dumazet
2012-06-01 18:24 ` David Miller
2012-06-01 21:34 ` Hans Schillström
2012-06-02 6:56 ` Eric Dumazet
2012-06-01 7:36 ` [PATCH net-next] tcp: avoid tx starvation by SYNACK packets Hans Schillstrom
2012-06-01 9:34 ` Eric Dumazet
2012-06-02 1:28 ` Dave Taht
2012-06-02 5:46 ` Eric Dumazet
2012-06-23 7:34 ` Vijay Subramanian
2012-06-23 8:42 ` [PATCH v2 " Eric Dumazet
2012-06-25 6:24 ` Hans Schillstrom
2012-06-25 22:43 ` David Miller
2012-06-26 4:51 ` Eric Dumazet
2012-06-26 4:55 ` David Miller
2012-06-26 5:34 ` Hans Schillstrom
2012-06-26 7:11 ` David Miller
2012-06-26 7:27 ` Hans Schillstrom
2012-06-26 17:02 ` Eric Dumazet
2012-06-27 5:23 ` Hans Schillstrom
2012-06-27 8:22 ` David Miller
2012-06-27 8:25 ` Jesper Dangaard Brouer
2012-06-27 8:30 ` Hans Schillstrom
2012-06-27 8:40 ` Eric Dumazet
2012-06-27 8:48 ` David Miller
2012-06-27 6:32 ` Jesper Dangaard Brouer
2012-06-27 6:54 ` David Miller
2012-06-27 7:24 ` Jesper Dangaard Brouer
2012-06-27 7:30 ` Eric Dumazet
2012-06-27 7:54 ` Jesper Dangaard Brouer
2012-06-27 8:02 ` Eric Dumazet
2012-06-27 8:21 ` Jesper Dangaard Brouer [this message]
2012-06-27 8:45 ` Eric Dumazet
2012-06-27 9:23 ` Jesper Dangaard Brouer
2012-06-27 8:13 ` David Miller
2012-06-27 19:50 ` Florian Westphal
2012-06-27 21:39 ` Eric Dumazet
2012-06-27 22:23 ` David Miller
2012-06-27 22:23 ` David Miller
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