Messages in this thread | | | Date | Wed, 28 Nov 2007 09:41:22 -0600 | From | Larry Finger <> | Subject | Re: Question regarding mutex locking |
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Andreas Schwab wrote: > Larry Finger <Larry.Finger@lwfinger.net> writes: > >> If a particular routine needs to lock a mutex, but it may be entered with that mutex already locked, >> would the following code be SMP safe? >> >> hold_lock = mutex_trylock() >> >> ... >> >> if (hold_lock) >> mutex_unlock() > > When two CPUs may enter the critical region at the same time, what is > the point of the mutex? Also, the first CPU may unlock the mutex while > the second one is still inside the critical region.
Thank you for that answer. I think that I'm finally beginning to understand.
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