From: Willy Tarreau <w@1wt.eu>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Major network performance regression in 3.7
Date: Sun, 6 Jan 2013 03:32:06 +0100 [thread overview]
Message-ID: <20130106023206.GX16031@1wt.eu> (raw)
In-Reply-To: <1357438933.1678.5223.camel@edumazet-glaptop>
On Sat, Jan 05, 2013 at 06:22:13PM -0800, Eric Dumazet wrote:
> On Sun, 2013-01-06 at 03:18 +0100, Willy Tarreau wrote:
> > On Sat, Jan 05, 2013 at 06:16:31PM -0800, Eric Dumazet wrote:
> > > On Sat, 2013-01-05 at 17:51 -0800, Eric Dumazet wrote:
> > > > On Sat, 2013-01-05 at 17:40 -0800, Eric Dumazet wrote:
> > > > > On Sun, 2013-01-06 at 02:30 +0100, Willy Tarreau wrote:
> > > > >
> > > > > > Ah interesting because these were some of the mm patches that I had
> > > > > > tried to revert.
> > > > >
> > > > > Hmm, or we should fix __skb_splice_bits()
> > > > >
> > > > > I'll send a patch.
> > > > >
> > > >
> > > > Could you try the following ?
> > >
> > > Or more exactly...
> >
> > The first one did not change a iota unfortunately. I'm about to
> > spot the commit causing the loopback regression. It's a few patches
> > before the first one you pointed. It's almost finished and I test
> > your patch below immediately after.
>
> I bet you are going to find commit
> 69b08f62e17439ee3d436faf0b9a7ca6fffb78db
> (net: use bigger pages in __netdev_alloc_frag )
>
> Am I wrong ?
Yes this time you guessed wrong :-) Well maybe it's participating
to the issue.
It's 0cf833ae (net: loopback: set default mtu to 64K). And I could
reproduce it with 3.6 by setting loopback's MTU to 65536 by hand.
The trick is that once the MTU has been set to this large a value,
even when I set it back to 16kB the problem persists.
Now I'm retrying your other patch to see if it brings the 10GE back
to full speed.
Willy
next prev parent reply other threads:[~2013-01-06 2:32 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-05 21:49 Major network performance regression in 3.7 Willy Tarreau
2013-01-05 23:18 ` Eric Dumazet
2013-01-05 23:29 ` Willy Tarreau
2013-01-06 0:02 ` Eric Dumazet
2013-01-06 0:50 ` Willy Tarreau
2013-01-06 1:21 ` Eric Dumazet
2013-01-06 1:30 ` Willy Tarreau
2013-01-06 1:40 ` Eric Dumazet
2013-01-06 1:51 ` Eric Dumazet
2013-01-06 2:16 ` Eric Dumazet
2013-01-06 2:18 ` Willy Tarreau
2013-01-06 2:22 ` Eric Dumazet
2013-01-06 2:32 ` Willy Tarreau [this message]
2013-01-06 2:44 ` Eric Dumazet
2013-01-06 2:52 ` Willy Tarreau
2013-01-06 7:31 ` [PATCH net-next] net: splice: avoid high order page splitting Eric Dumazet
2013-01-07 5:07 ` David Miller
2013-01-06 7:35 ` Major network performance regression in 3.7 Eric Dumazet
2013-01-06 9:24 ` Willy Tarreau
2013-01-06 10:25 ` Willy Tarreau
2013-01-06 11:46 ` Romain Francoise
2013-01-06 11:53 ` Willy Tarreau
2013-01-06 12:01 ` Willy Tarreau
2013-01-06 14:59 ` Eric Dumazet
2013-01-06 15:51 ` Willy Tarreau
2013-01-06 16:39 ` Eric Dumazet
2013-01-06 16:44 ` Willy Tarreau
2013-01-06 17:10 ` Eric Dumazet
2013-01-06 17:35 ` Willy Tarreau
2013-01-06 18:39 ` Eric Dumazet
2013-01-06 18:43 ` Eric Dumazet
2013-01-06 18:51 ` Eric Dumazet
2013-01-06 19:00 ` Eric Dumazet
2013-01-06 19:34 ` Willy Tarreau
2013-01-06 19:39 ` Eric Dumazet
2013-01-06 19:53 ` Willy Tarreau
2013-01-07 4:21 ` [PATCH] tcp: fix MSG_SENDPAGE_NOTLAST logic Eric Dumazet
2013-01-07 4:59 ` David Miller
2013-01-06 21:49 ` Major network performance regression in 3.7 John Stoffel
2013-01-06 21:52 ` Willy Tarreau
2013-01-06 21:55 ` John Stoffel
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