From: Chen Gang <gang.chen@asianux.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: edumazet@google.com, Pravin Shelar <pshelar@nicira.com>,
mgorman@suse.de, David Miller <davem@davemloft.net>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
Ben Hutchings <bhutchings@solarflare.com>
Subject: Re: [PATCH] include/linux/skbuff.h: using '0xffff' instead of '~0U'
Date: Mon, 03 Jun 2013 18:51:50 +0800 [thread overview]
Message-ID: <51AC7546.4010002@asianux.com> (raw)
In-Reply-To: <CAHp75Vc19Kii7_TF+9aF4ZeKAa4_92DCVL+u1duZDTu38o2qsw@mail.gmail.com>
On 06/03/2013 06:14 PM, Andy Shevchenko wrote:
> On Mon, Jun 3, 2013 at 12:23 PM, Chen Gang <gang.chen@asianux.com> wrote:
>> On 06/01/2013 05:05 AM, Andy Shevchenko wrote:
>
>>> Why not "(u16)~0" ?
>> We'd better to give a meaningful name to it just like Ben said.
>
> Yeah, you could give a name, though I don't see this needs for
> constants like (u16)~0. It's a usual way to mark some values
> uninitialized.
> Just an example from kernel:
>
> /* This is limited by 16 bit "slot" numbers,
> * and by available on-disk context storage.
> *
> * Also (u16)~0 is special (denotes a "free" extent).
>
After "fgrep -rn 'u16' * | fgrep '~0'", it seems better to define a
meaningful macro for it (e.g. "#define SKB_HEADER_WAS_UNSET 0xffff").
Thanks.
--
Chen Gang
Asianux Corporation
next prev parent reply other threads:[~2013-06-03 10:52 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-30 6:03 [PATCH] include/linux/skbuff.h: using '0xffff' instead of '~0U' Chen Gang
2013-05-30 9:55 ` Chen Gang
2013-05-30 15:30 ` Ben Hutchings
2013-06-03 8:52 ` Chen Gang
2013-05-31 21:05 ` Andy Shevchenko
2013-06-03 9:23 ` Chen Gang
2013-06-03 10:14 ` Andy Shevchenko
2013-06-03 10:51 ` Chen Gang [this message]
2013-06-03 11:24 ` [PATCH v2] include/linux/skbuff.h: using '(u16) ~0U' " Chen Gang
2013-06-03 11:34 ` Andy Shevchenko
2013-06-03 11:46 ` Chen Gang
2013-06-03 12:26 ` David Laight
2013-06-03 12:26 ` David Laight
2013-06-03 12:47 ` David Laight
2013-06-03 12:47 ` David Laight
2013-06-05 0:44 ` Chen Gang
2013-06-05 0:54 ` [PATCH v3] include/linux/skbuff.h: using '(__u16) " Chen Gang
2013-06-05 8:36 ` David Miller
2013-06-05 11:15 ` Chen Gang
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