From: Michael Ellerman <michael@ellerman.id.au>
To: Sean MacLennan <seanm@seanm.ca>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: WARNING: mutexes are preferred for single holder semaphores
Date: Mon, 05 May 2008 11:06:55 +1000 [thread overview]
Message-ID: <1209949615.8159.7.camel@localhost> (raw)
In-Reply-To: <20080504204104.7eea7618@lappy.seanm.ca>
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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
--
Michael Ellerman
OzLabs, IBM Australia Development Lab
wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)
We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person
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next prev parent reply other threads:[~2008-05-05 1:06 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 [this message]
2008-05-05 1:31 ` Sean MacLennan
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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