From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shirley Ma <mashirle@us.ibm.com>
Subject: Re: [RFC PATCH V2 5/5] Add TX zero copy in macvtap
Date: Fri, 10 Dec 2010 08:38:08 -0800
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	 <1291976864.3580.7.camel@edumazet-laptop>
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Cc: Avi Kivity <avi@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
	mst@redhat.com, xiaohui.xin@intel.com, netdev@vger.kernel.org,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Fri, 2010-12-10 at 08:25 -0800, Shirley Ma wrote:
> On Fri, 2010-12-10 at 11:27 +0100, Eric Dumazet wrote:
> > You could make one atomic_add() outside of the loop, and factorize
> > many
> > things...
> > 
> > atomic_add(len, &skb->sk->sk_wmem_alloc);
> > skb->data_len += len;
> > skb->len += len;
> > skb->truesize += len;
> > while (len) {
> >         ...
> > } 
> 
> Yep, thanks, will update it! 

Maybe I should use total_len when skb frag mapping is done, something
like:

int total_len = 0;
...
total len += len;
...
skb->data_len += total_len;
skb->len += total_len;
skb->truesize += total_len;
atomic_add(total_len, &skb->sk->sk_wmem_alloc);

Shirley