From: Andrew Morton <akpm@linux-foundation.org>
To: Joe Perches <joe@perches.com>
Cc: akinobu.mita@gmail.com, nickpiggin@yahoo.com.au,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] lib: introduce call_once()
Date: Tue, 11 Mar 2008 12:11:07 -0700 [thread overview]
Message-ID: <20080311121107.4774ff5e.akpm@linux-foundation.org> (raw)
In-Reply-To: <1205261815.3165.21.camel@localhost>
On Tue, 11 Mar 2008 11:56:55 -0700
Joe Perches <joe@perches.com> wrote:
> On Tue, 2008-03-11 at 10:35 -0700, Andrew Morton wrote:
> > #define ONCE() \
> > ({ \
> > static long flag; \
> > \
> > return !test_and_set_bit(0, flag); \
> > })
>
> test_and_set_bit takes an address
duh.
> Perhaps:
>
> #define DO_ONCE(x) \
> ({ static long flag; if (test_and_set_bit(0, &flag)) x; 1; })
>
> DO_ONCE(foo);
No, that's completely unnecessary and would produce nasty-looking code.
Take a look at some of the wait_event monstrosities we have.
I'm not sure that we need any of this once() stuff really.
next prev parent reply other threads:[~2008-03-11 19:11 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-10 14:57 [PATCH 1/5] lib: introduce call_once() Akinobu Mita
2008-03-10 15:00 ` [PATCH 2/5] idr: use call_once() Akinobu Mita
2008-03-10 15:01 ` [PATCH 3/5] hugetlbfs: " Akinobu Mita
2008-03-10 15:03 ` [PATCH 4/5] shmem: " Akinobu Mita
2008-03-10 15:05 ` [PATCH 5/5] tiny-shmem: " Akinobu Mita
2008-03-10 22:15 ` [PATCH 4/5] shmem: " Hugh Dickins
2008-03-11 12:29 ` Akinobu Mita
2008-03-11 13:41 ` Hugh Dickins
2008-03-10 15:29 ` [PATCH 1/5] lib: introduce call_once() Joe Perches
2008-03-11 12:17 ` Akinobu Mita
2008-03-11 3:48 ` Andrew Morton
2008-03-11 4:10 ` Nick Piggin
2008-03-11 4:21 ` Andrew Morton
2008-03-11 12:27 ` Akinobu Mita
2008-03-11 17:35 ` Andrew Morton
2008-03-11 18:56 ` Joe Perches
2008-03-11 19:11 ` Andrew Morton [this message]
2008-03-15 4:01 ` Akinobu Mita
2008-03-11 12:41 ` Nick Piggin
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