From: Sean MacLennan <seanm@seanm.ca>
To: <michael@ellerman.id.au>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: WARNING: mutexes are preferred for single holder semaphores
Date: Sun, 4 May 2008 21:31:26 -0400 [thread overview]
Message-ID: <20080504213126.3e363f5e@lappy.seanm.ca> (raw)
In-Reply-To: <1209949615.8159.7.camel@localhost>
On Mon, 05 May 2008 11:06:55 +1000
"Michael Ellerman" <michael@ellerman.id.au> wrote:
> On Sun, 2008-05-04 at 20:41 -0400, Sean MacLennan wrote:
> > This is a bit OT, but I got the warning in the subject from
> > checkpatch.pl for a piece of code. The code *is* using a mutex.
> > Does it actually mean I shouldn't use a mutex?
> >
> > The code declares a global mutex:
> >
> > static DECLARE_MUTEX(list_lock);
>
> .. which is a semaphore :( [see include/linux/semaphore.h]
>
> I think you want DEFINE_MUTEX().
>
> Yes, this is completely ridiculous.
>
> cheers
>
Ok, that fixed it, once I changed all the up and down calls :p
Thanks.
Cheers,
Sean
next prev parent reply other threads:[~2008-05-05 1:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-05 0:41 WARNING: mutexes are preferred for single holder semaphores Sean MacLennan
2008-05-05 1:06 ` Michael Ellerman
2008-05-05 1:31 ` Sean MacLennan [this message]
2008-05-05 2:13 ` Paul Mackerras
2008-05-05 6:01 ` Christoph Hellwig
2008-05-05 3:38 ` Benjamin Herrenschmidt
2008-05-05 4:40 ` Sean MacLennan
2008-05-07 14:36 ` All your drivers are belong to us [was WARNING: mutexes are preferred for single holder semaphores] Detlev Zundel
2008-05-07 21:42 ` All your drivers are belong to us [was WARNING: mutexes are preferredfor " Sean MacLennan
2008-05-08 0:49 ` Josh Boyer
2008-05-08 4:41 ` Sean MacLennan
2008-05-08 13:28 ` All your drivers are belong to us Detlev Zundel
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