Hi Pascal,

> [...]
>> If it fails to obtain the lock, it waits
>> (sleeps, spins it's wheels) until the thread which holds the lock
>> releases it.
> The difference is exactly in the "sleeps, spins it's wheels"
part. A spinlock
> is a lock which you cannot sleep on, only busy-waiting in a tight loop is
>allowed. A lock you can sleep on is called a semaphore - at least those are th
> right terms when talking about the Linux kernel.

Ah..

> Spinlocks are used to synchronize between different interrupt handlers or
> between interrupt handlers and normal kernel code - an interrupt handler
> *cannot* sleep, therefore a semaphore would not work.

Ok, makes sense.

Take care,
Janis

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