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From: Jason Wang <jasowang@redhat.com>
To: Herbert Xu <herbert@gondor.hengli.com.au>,
	Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>,
	David Miller <davem@davemloft.net>,
	christoph.paasch@uclouvain.be, netdev@vger.kernel.org,
	hkchu@google.com, mwdalton@google.com, mst@redhat.com
Subject: Re: gso: Attempt to handle mega-GRO packets
Date: Thu, 07 Nov 2013 10:52:57 +0800	[thread overview]
Message-ID: <527B0089.4030605@redhat.com> (raw)
In-Reply-To: <20131107003658.GA27976@gondor.apana.org.au>

On 11/07/2013 08:36 AM, Herbert Xu wrote:
> On Wed, Nov 06, 2013 at 07:01:10AM -0800, Eric Dumazet wrote:
>> Have you thought about arches having PAGE_SIZE=65536, and how bad it is
>> to use a full page per network frame ? It is lazy and x86 centered.
> So instead if we were sending a full 64K packet on such an arch to
> another guest, we'd now chop it up into 1.5K chunks and reassemble them.
>
>> So after our patches, we now have an optimal situation, even on these
>> arches.
> Optimal only for physical incoming packets with no jumbo frames.
>
> What's worse, I now realise that the coalesce thing isn't even
> guaranteed to work.  It probably works in your benchmarks because
> you're working with freshly allocated pages.
>
> But once the system has been running for a while, I see nothing
> in the virtio_net code that tries to prevent fragmentation.  Once
> fragmentation sets in, you'll be back in the terrible situation
> that we were in prior to the coalesce patch.
>
> Jason/Michael (Tsirkin), am I missing something that would prevent
> fragmentation of these buffers?
>
> Cheers,

No. Maybe we can use per-queue buffers instead.

  parent reply	other threads:[~2013-11-07  2:53 UTC|newest]

Thread overview: 163+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-28 11:55 Bug in skb_segment: fskb->len != len Christoph Paasch
2013-10-28 13:21 ` Eric Dumazet
2013-10-28 13:28   ` Christoph Paasch
2013-10-29  1:15   ` Eric Dumazet
2013-10-29  9:08     ` Christoph Paasch
2013-10-29 12:57       ` Eric Dumazet
2013-10-29 13:06       ` [PATCH net-next] net: introduce gro_frag_list_enable sysctl Eric Dumazet
2013-10-29 13:48         ` Christoph Paasch
2013-10-29 15:12         ` [PATCH v2 " Eric Dumazet
2013-10-29 23:44           ` David Miller
2013-10-30  0:06             ` Ben Hutchings
2013-11-02 14:01               ` [PATCH v3 net-next] net: introduce dev_set_forwarding() Eric Dumazet
2013-11-02 15:46                 ` Ben Hutchings
2013-11-02 18:20                   ` Eric Dumazet
2013-11-02 19:58                 ` [PATCH v4 " Eric Dumazet
2013-11-03 17:18                   ` Christoph Paasch
2013-11-04 16:55                   ` Ben Hutchings
2013-11-07 21:17                     ` David Miller
2013-11-07 21:31                       ` Herbert Xu
2013-11-07 21:54                         ` Eric Dumazet
2013-11-08  3:59                           ` Herbert Xu
2013-11-08  4:25                             ` Eric Dumazet
2013-11-10 14:05                               ` Herbert Xu
2013-11-11 14:36                                 ` Herbert Xu
2013-11-07 22:06                         ` David Miller
2013-11-08  2:17                           ` Herbert Xu
2013-11-08  2:42                             ` Eric Dumazet
2013-11-08  2:51                               ` Eric Dumazet
2013-11-08  3:23                                 ` Herbert Xu
2013-11-08  4:21                                   ` Eric Dumazet
2013-11-08  4:24                                     ` Herbert Xu
2013-11-08  4:40                                       ` Eric Dumazet
2013-11-08  4:43                                         ` Herbert Xu
2013-11-08  5:08                                           ` Eric Dumazet
2013-11-08  5:21                                             ` Herbert Xu
2013-11-08  5:40                                               ` Eric Dumazet
2013-11-11 18:58                                                 ` Herbert Xu
2013-11-08  3:22                               ` Herbert Xu
2013-11-08  4:06                                 ` Eric Dumazet
2013-11-08  4:10                                   ` Herbert Xu
2013-11-08  4:24                                     ` Eric Dumazet
2013-11-08  4:28                                       ` Herbert Xu
2013-11-21 18:29                   ` David Miller
2013-11-21 18:38                     ` Eric Dumazet
2013-11-03 12:28                 ` [PATCH v3 " Herbert Xu
2013-11-03 16:28                   ` Eric Dumazet
2013-11-03 16:31                     ` Herbert Xu
2013-11-03 17:26                       ` Eric Dumazet
2013-11-04  4:11                         ` Herbert Xu
2013-11-04  4:23                           ` Eric Dumazet
2013-11-04  4:29                             ` Herbert Xu
2013-11-04  5:00                               ` Eric Dumazet
2013-11-04  5:23                                 ` Herbert Xu
2013-11-04  6:05                                   ` Eric Dumazet
2013-11-04  6:22                                     ` Herbert Xu
2013-11-04  6:26                                       ` Herbert Xu
2013-11-04  7:10                                         ` Eric Dumazet
2013-11-04  7:21                                           ` Herbert Xu
2013-11-04 13:58                                             ` Eric Dumazet
2013-11-04  6:46                                       ` Eric Dumazet
2013-11-04  7:03                                         ` Herbert Xu
2013-11-06  1:30                           ` gso: Attempt to handle mega-GRO packets Herbert Xu
2013-11-06  1:45                             ` Eric Dumazet
2013-11-06  4:07                               ` Herbert Xu
2013-11-06  4:23                                 ` Eric Dumazet
2013-11-06  4:28                                   ` Herbert Xu
2013-11-06  5:20                                     ` Eric Dumazet
2013-11-06  8:04                                       ` Herbert Xu
2013-11-06  8:16                                         ` Herbert Xu
2013-11-06 13:12                                           ` Herbert Xu
2013-11-06 15:01                                             ` Eric Dumazet
2013-11-07  0:36                                               ` Herbert Xu
2013-11-07  1:03                                                 ` Eric Dumazet
2013-11-07  1:47                                                   ` Herbert Xu
2013-11-07  2:02                                                     ` Eric Dumazet
2013-11-07  2:08                                                       ` Eric Dumazet
2013-11-07  2:15                                                       ` Herbert Xu
2013-11-07  2:37                                                         ` Eric Dumazet
2013-11-07  2:41                                                           ` Herbert Xu
2013-11-07  5:56                                                       ` Michael S. Tsirkin
2013-11-07  7:07                                                         ` Eric Dumazet
2013-11-07  2:52                                                 ` Jason Wang [this message]
2013-11-06 15:05                                           ` Eric Dumazet
2013-11-07  0:39                                             ` Herbert Xu
2013-11-06 12:39                             ` Herbert Xu
2013-11-06 13:30                               ` Herbert Xu
2013-11-06 14:39                                 ` Herbert Xu
2013-11-06 15:06                                   ` Eric Dumazet
2013-11-06 17:25                                   ` Joe Perches
2013-11-06 19:47                                   ` Eric Dumazet
2013-11-07  0:15                                     ` Eric Dumazet
2013-11-07  0:47                                       ` Herbert Xu
2013-11-07  0:56                                         ` Eric Dumazet
2013-11-07  1:00                                           ` Herbert Xu
2013-11-07  1:08                                             ` Eric Dumazet
2013-11-07  1:13                                       ` Hannes Frederic Sowa
2013-11-07  1:21                                         ` Eric Dumazet
2013-11-07  1:34                                           ` Eric Dumazet
2013-11-07  2:03                                             ` Hannes Frederic Sowa
2013-11-07  3:05                                               ` Eric Dumazet
2013-11-07  6:59                                                 ` Eric Dumazet
2013-11-07  0:43                                     ` Herbert Xu
2013-11-07  6:22                                       ` Herbert Xu
2013-11-07  7:03                                         ` [1/3] gso: Add to segs at end of loop in skb_segment Herbert Xu
2013-11-07  7:06                                           ` [2/3] gso: Handle new frag_list of frags GRO packets Herbert Xu
2013-11-07  7:08                                             ` [3/3] gso: Handle malicious GRO packets without crashing Herbert Xu
2013-11-07 18:18                                               ` Ben Hutchings
2013-11-07 19:13                                               ` Sergei Shtylyov
2013-11-11 18:55                                                 ` Herbert Xu
2013-11-07 18:16                                             ` [2/3] gso: Handle new frag_list of frags GRO packets Ben Hutchings
2013-11-11 18:54                                               ` Herbert Xu
2013-11-11 18:52                                             ` Herbert Xu
2013-11-12 10:12                                               ` David Laight
2013-11-13  1:13                                               ` gso: " Eric Dumazet
2013-11-13  1:29                                                 ` Herbert Xu
2013-11-13  2:14                                                   ` Eric Dumazet
2013-11-13  2:17                                                   ` Eric Dumazet
2013-11-13  2:22                                                     ` Herbert Xu
2013-11-13  2:25                                                       ` Herbert Xu
2013-11-13  2:45                                                         ` Eric Dumazet
2013-11-13 14:26                                                           ` Herbert Xu
2013-11-13 15:06                                                             ` Eric Dumazet
2013-11-14  8:11                                                               ` Herbert Xu
2013-11-15  4:37                                                                 ` Eric Dumazet
2013-11-13  2:31                                                       ` Eric Dumazet
2013-11-07  7:11                                       ` gso: Attempt to handle mega-GRO packets Eric Dumazet
2013-11-07  7:15                                         ` Herbert Xu
2013-11-07  7:17                                           ` Herbert Xu
2013-11-07  7:31                                           ` Eric Dumazet
2013-11-07  7:33                                             ` Herbert Xu
2013-11-03 23:23                     ` [PATCH v3 net-next] net: introduce dev_set_forwarding() David Miller
2013-10-30  0:53             ` [PATCH v2 net-next] net: introduce gro_frag_list_enable sysctl Eric Dumazet
2013-10-30  2:02               ` David Miller
2013-10-30  2:05                 ` Herbert Xu
2013-10-30  2:13                   ` Jerry Chu
2013-10-30  2:19                     ` Herbert Xu
2013-10-30  2:34                       ` David Miller
2013-10-30  2:33                     ` David Miller
     [not found]                       ` <44571383414236@web13j.yandex.ru>
2013-11-02 18:28                         ` Eric Dumazet
2013-11-03 23:19                         ` David Miller
2013-10-30 19:39                   ` Ben Hutchings
2013-10-30 19:53                     ` Eric Dumazet
2013-10-30 20:05                       ` Ben Hutchings
2013-10-30 20:12                         ` Eric Dumazet
2013-10-30  4:06                 ` Eric Dumazet
2013-10-30  4:08                   ` Herbert Xu
2013-10-30  4:09                     ` Herbert Xu
2013-10-30  4:15                       ` Jerry Chu
2013-10-30  4:16                     ` Eric Dumazet
2013-10-30  4:19                       ` Herbert Xu
2013-10-30  4:34                         ` Eric Dumazet
2013-10-30  4:42                           ` Herbert Xu
2013-10-30 17:39                             ` Jerry Chu
2013-10-30 18:09                               ` Vlad Yasevich
2013-10-30 19:12                               ` David Miller
2013-10-30  0:03           ` Jerry Chu
2013-10-29 14:41     ` Bug in skb_segment: fskb->len != len Herbert Xu
2013-10-29 15:08       ` Eric Dumazet
2013-10-30  1:50         ` Herbert Xu
2013-10-30  4:03           ` Eric Dumazet
2013-10-30  4:06             ` Herbert Xu
2013-10-30  4:37               ` Eric Dumazet
2013-10-30  4:47                 ` Herbert Xu

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