From: Sean MacLennan <seanm@seanm.ca>
To: <linuxppc-dev@ozlabs.org>
Subject: WARNING: mutexes are preferred for single holder semaphores
Date: Sun, 4 May 2008 20:41:04 -0400 [thread overview]
Message-ID: <20080504204104.7eea7618@lappy.seanm.ca> (raw)
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);
The odds of two accesses to the list_lock at the same time are zero.
But it would be Very Bad(tm) if it did happen. Since the odds of
contention are near zero, the cost of the mutex is near zero, so I put
it in.
I think I can safely ignore the warning, but I want to make sure....
Cheers,
Sean
next reply other threads:[~2008-05-05 0:41 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-05 0:41 Sean MacLennan [this message]
2008-05-05 1:06 ` WARNING: mutexes are preferred for single holder semaphores Michael Ellerman
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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