From: David L Stevens <david.stevens@oracle.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCHv4 net-next 2/3] sunvnet: allow admin to set sunvnet MTU
Date: Tue, 16 Sep 2014 14:51:37 -0400 [thread overview]
Message-ID: <541886B9.3010206@oracle.com> (raw)
In-Reply-To: <541785D8.5030101@oracle.com>
On 09/15/2014 08:35 PM, David L Stevens wrote:
> */
> #define VNET_TX_TIMEOUT (5 * HZ)
>
> -#define VNET_MAXPACKET 1518ULL /* ETH_FRAMELEN + VLAN_HDR */
> +#define VNET_MAXPACKET 65553ULL /* 64K-1 +ETH HDR +VLAN HDR*/
> #define VNET_TX_RING_SIZE 512
> #define VNET_TX_WAKEUP_THRESH(dr) ((dr)->pending / 4)
While looking at adding TSO support, I've turned up a bug with this.
The transmit buffer mapping should be using a cookie per-page and this increases
the page count (without page alignment) from 2 with a 1500-byte MTU to 10 with a 64K MTU
+ framing and allowing from unaligned buffers.
I think it worked during my testing because the pages were contiguous, but the tx buffer
allocation code is assuming 2 pages (and 2 cookies) max.
So, it's incorrect. I'll fix and repost; please don't apply these yet.
+-DLS
next prev parent reply other threads:[~2014-09-16 18:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-16 0:35 [PATCHv4 net-next 2/3] sunvnet: allow admin to set sunvnet MTU David L Stevens
2014-09-16 18:51 ` David L Stevens [this message]
2014-09-16 19:10 ` David Miller
2014-09-17 9:07 ` David Laight
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