From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <erdnetdev@gmail.com>
Subject: Re: [PATCH] xen/netfront: improve truesize tracking
Date: Tue, 18 Dec 2012 08:13:00 -0800
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Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Sander Eikelenboom <linux@eikelenboom.it>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
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To: Ian Campbell <Ian.Campbell@citrix.com>
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On Tue, 2012-12-18 at 15:26 +0000, Ian Campbell wrote:

> So actually we want += PAGE_SIZE * skb_shinfo(skb)->nr_frags ?
> 

I dont know what are the real frag sizes in your case.

Some drivers allocate a full page for an ethernet frame, others use half
of a page, it really depends.

As the frag ABI doesnt contain real size, its ok in this case to account
the actual frag size.

(skb->data_len in your driver)