From: "Michael S. Tsirkin" <mst@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>, David Miller <davem@davemloft.net>,
netdev@vger.kernel.org
Subject: Re: [PATCH net-next] net: netdev_alloc_skb() use build_skb()
Date: Mon, 4 Jun 2012 22:43:31 +0300 [thread overview]
Message-ID: <20120604194330.GA1648@redhat.com> (raw)
In-Reply-To: <1338838185.2760.1899.camel@edumazet-glaptop>
On Mon, Jun 04, 2012 at 09:29:45PM +0200, Eric Dumazet wrote:
> On Mon, 2012-06-04 at 21:16 +0300, Michael S. Tsirkin wrote:
>
> > Yes but if a tcp socket then hangs on, on one of the fragments,
> > while the other has been freed, the whole page is still
> > never reused, right?
> >
> > Doesn't this mean truesize should be 4K?
> >
>
> Yes, or more exactly PAGE_SIZE, but then performance would really go
> down on machines with 64KB pages.
> Maybe we should make the whole frag
> head idea enabled only for PAGE_SIZE=4096.
>
> Not sure we want to track precise truesize, as the minimum truesize is
> SKB_DATA_ALIGN(length + NET_SKB_PAD) + SKB_DATA_ALIGN(sizeof(struct
> skb_shared_info)) (64 + 64 + 320) = 448
>
> Its not like buggy drivers that used truesize = length
>
>
Interesting. But where's the threshold?
--
MST
next prev parent reply other threads:[~2012-06-04 19:43 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-17 12:18 Stable regression with 'tcp: allow splice() to build full TSO packets' Willy Tarreau
2012-05-17 15:01 ` Willy Tarreau
2012-05-17 15:43 ` Eric Dumazet
2012-05-17 15:56 ` Willy Tarreau
2012-05-17 16:33 ` Eric Dumazet
2012-05-17 16:40 ` Willy Tarreau
2012-05-17 16:47 ` Eric Dumazet
2012-05-17 16:49 ` Eric Dumazet
2012-05-17 17:22 ` Willy Tarreau
2012-05-17 17:34 ` [PATCH net-next] net: netdev_alloc_skb() use build_skb() Eric Dumazet
2012-05-17 17:45 ` Willy Tarreau
2012-06-04 12:39 ` Michael S. Tsirkin
2012-06-04 12:44 ` Willy Tarreau
2012-05-17 19:53 ` David Miller
2012-05-18 4:41 ` Eric Dumazet
2012-06-04 12:37 ` Michael S. Tsirkin
2012-06-04 13:06 ` Eric Dumazet
2012-06-04 13:41 ` Michael S. Tsirkin
2012-06-04 14:01 ` Eric Dumazet
2012-06-04 14:09 ` Eric Dumazet
2012-06-04 14:17 ` Michael S. Tsirkin
2012-06-04 15:01 ` Eric Dumazet
2012-06-04 17:20 ` Michael S. Tsirkin
2012-06-04 17:44 ` Eric Dumazet
2012-06-04 18:16 ` Michael S. Tsirkin
2012-06-04 19:24 ` Eric Dumazet
2012-06-04 19:48 ` Michael S. Tsirkin
2012-06-04 19:56 ` Eric Dumazet
2012-06-04 21:20 ` Michael S. Tsirkin
2012-06-05 2:50 ` Eric Dumazet
2012-06-04 18:16 ` Michael S. Tsirkin
2012-06-04 19:29 ` Eric Dumazet
2012-06-04 19:43 ` Michael S. Tsirkin [this message]
2012-06-04 19:52 ` Eric Dumazet
2012-06-04 21:54 ` Michael S. Tsirkin
2012-06-05 2:46 ` Eric Dumazet
2012-06-04 19:56 ` Michael S. Tsirkin
2012-06-04 20:05 ` Eric Dumazet
2012-05-17 18:38 ` Stable regression with 'tcp: allow splice() to build full TSO packets' Ben Hutchings
2012-05-17 19:55 ` David Miller
2012-05-17 20:04 ` Willy Tarreau
2012-05-17 20:07 ` David Miller
2012-05-17 20:41 ` Eric Dumazet
2012-05-17 21:14 ` Willy Tarreau
2012-05-17 21:40 ` Eric Dumazet
2012-05-17 21:50 ` Eric Dumazet
2012-05-17 21:57 ` Willy Tarreau
2012-05-17 22:01 ` Eric Dumazet
2012-05-17 22:10 ` Eric Dumazet
2012-05-17 22:16 ` Willy Tarreau
2012-05-17 22:22 ` Eric Dumazet
2012-05-17 22:24 ` Willy Tarreau
2012-05-17 22:25 ` David Miller
2012-05-17 22:30 ` Willy Tarreau
2012-05-17 22:35 ` David Miller
2012-05-17 22:49 ` Willy Tarreau
2012-05-17 22:27 ` Joe Perches
2012-05-17 21:54 ` Willy Tarreau
2012-05-17 21:47 ` Willy Tarreau
2012-05-17 22:14 ` Eric Dumazet
2012-05-17 22:29 ` Willy Tarreau
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