[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20111122174205.6ef2021d@thirdoffive.cmf.nrl.navy.mil>
Date: Tue, 22 Nov 2011 17:42:05 -0500
From: chas williams - CONTRACTOR <chas@....nrl.navy.mil>
To: Eric Dumazet <eric.dumazet@...il.com>
Cc: netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next] atm: use SKB_TRUESIZE() in
atm_guess_pdu2truesize()
On Tue, 22 Nov 2011 21:33:54 +0100
Eric Dumazet <eric.dumazet@...il.com> wrote:
> Le mardi 22 novembre 2011 à 15:22 -0500, chas williams - CONTRACTOR a
> écrit :
> > it doesnt seem like a good idea to create a wrapper for a one to one
> > call. perhaps this whole bit of nonsense should be removed. the
> > iphase driver should be returning skb->truesize like everyone.
> >
> > if atm_alloc_charge() just uses SKB_TRUESIZE() then we konw that guess
> > will be the same as skb->truesize and atm_alloc_charge() can be
> > simplified by removing atomic_add(skb->truesize - guess, which will be
> > 0 in all cases.
> >
>
> Please note I didnt create a wrapper, only correct existing one :)
>
> Feel free to send a (tested) patch, but be warned that following code is
> not correct :
>
> int size = something;
>
> struct sk_buff *skb = skb_alloc(size);
>
> ASSERT(skb->truesize == SKB_TRUESIZE(size));
>
> (It might be true with SLOB only)
perhaps it is best to say that you discovered an inadvertent wrapper.
given skb->truesize != SKB_TRUESIZE() for all cases, it is certainly
wrong in the iphase driver to return the guessed value. it should be
returning skb->truesize. i will send along a patch shortly to just get
rid of this function.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists