Date: Sat, 24 Sep 2005 01:30:21 +0200
From: "J.A. Magallon" <jamagallon@able.es>
To: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] reduce sizeof(struct file)
Message-ID: <20050924013021.1130f3c8@werewolf.able.es>
In-Reply-To: <20050923100541.GA18447@infradead.org>
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	<4333CF4C.2000306@anagramm.de>
	<4333D2AA.6020009@cosmosbay.com>
	<20050923100541.GA18447@infradead.org>
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On Fri, 23 Sep 2005 11:05:41 +0100, Christoph Hellwig <hch@infradead.org> w=
rote:

> On Fri, Sep 23, 2005 at 12:02:18PM +0200, Eric Dumazet wrote:
> > Hi all
> >=20
> > Now that RCU applied on 'struct file' seems stable, we can place f_rcuh=
ead=20
> > in a memory location that is not anymore used at call_rcu(&f->f_rcuhead=
,=20
> > file_free_rcu) time, to reduce the size of this critical kernel object.
> >=20
> > The trick I used is to move f_rcuhead and f_list in an union and defini=
ng=20
> > macros to access f_list and f_rcuhead
> >=20
> > Unfortunatly f_list was also used in IPVS so I had to change=20
> > include/net/ip_vs.h and net/ipv4/ipvs/ip_vs_ctl.c, changing their f_lis=
t to=20
> > ipvs_f_list to avoid name clash.
> >=20
> > (This is why I send this mail to IPVS maintainers)
>=20
> Please just change all callers to use the union, there's not very many
> of them.
>=20

How about anonymous unions ? gcc-3.3.3 and above support them.
Is 2.6 supposed to be built with 2.95 ?

--
J.A. Magallon <jamagallon()able!es>     \               Software is like se=
x:
werewolf!able!es                         \         It's better when it's fr=
ee
Mandriva Linux release 2006.0 (2006 rc2) for i586
Linux 2.6.13-jam6 (gcc 4.0.1 (4.0.1-5mdk for Mandriva Linux release 2006.0))

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