Re: [PATCH] use spinlock instead of binary mutex in idt77252 driver

hi,

El Mon, Apr 23, 2007 at 09:40:19AM +0200 Eddie C. Dost ha dit:

as long as mutexes are not converted to nop when CONFIG_SMP is not
defined (I don't know what current kernels do), this is of course
correct. You need to verify the headerfiles for the above.

i just checked this, neither the mutex header nor implementation files
handle things different for CONFIG_SMP.

thanks for your comments

On Mon, Apr 23, 2007 at 09:40:26AM +0200, Matthias Kaehlcke wrote:
El Mon, Apr 23, 2007 at 09:16:08AM +0200 Eddie C. Dost ha dit:

Please note that the semaphore is used to lock the idt77252 config
tables among multiple users including atmsigd even on single processor
machines. Does this work with mutexes?

afaik mutexes have the same behaviour as binary semaphores that are
used as mutexes (always locked and unlocked by the same
process/thread):

".. the semaphore type can officially be considered to be on its way
out. New code should not use semaphores, and old code which uses
semaphores as mutexes should be converted over when an opportunity
presents itself."

http://lwn.net/Articles/167034/

please correct me if i'm wrong, i'm just doing my first steps with
linux kernel development

--
Matthias Kaehlcke
Linux Application Developer
Barcelona

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