Hi everyone, It's an extract in LDD3 , regarding spink lock. I have put my query in brackets. Spinlocks are, by their nature, intended for use on multiprocessor systems, although a uniprocessor workstation running a preemptive kernel behaves like SMP, as far as concurrency is concerned. ( I need to understand , how this is true with an example preferably ) If a nonpreemptive uniprocessor system ever went into a spin on a lock, it would spin forever; no other thread would ever be able to obtain the CPU to release the lock. For this reason, spinlock operations on uniprocessor systems without pre-emption enabled are optimized to do nothing, with the exception of the ones that change the IRQ masking status. ( I don't get the meaning of last sentence "with the exception of ......" Please can somebody explain ) Thanks and Regards Smital Desai This Email may contain confidential or privileged information for the intended recipient (s) If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system. ______________________________________________________________________ -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
