Hello!
On Thu, May 10, 2007 at 02:20:19PM -0600, Jonathan Corbet wrote:
...
> +++ b/Documentation/volatile-considered-harmful.txt
...
> +Consider a typical block of kernel code:
> +
> + spin_lock(&the_lock);
> + do_something_on(&shared_data);
^^^^^^^^^^^
> + do_something_else_with(&shared_data);
^^^^^^^^^^^
> + spin_unlock(&the_lock);
> +
> +If all the code follows the locking rules, the value of shared_data cannot
> +change unexpectedly while the_lock is held. Any other code which might
> +want to play with that data will be waiting on the lock. The spinlock
> +primitives act as memory barriers - they are explicitly written to do so -
> +meaning that data accesses will not be optimized across them. So the
> +compiler might think it knows what will be in some_data, but the
s/some_data/shared_data/ ? ^^^^^^^^^
BYtE
Philipp
--
/ / (_)__ __ ____ __ Philipp Hahn
/ /__/ / _ \/ // /\ \/ /
/____/_/_//_/\_,_/ /_/\_\ [email protected]
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