Re: [PATCH v5 09/13] xen/spinlock: split recursive spinlocks from normal ones

[Jan Beulich <jbeulich@xxxxxxxx>]

On 14.03.2024 08:20, Juergen Gross wrote:
> Recursive and normal spinlocks are sharing the same data structure for
> representation of the lock. This has two major disadvantages:
> 
> - it is not clear from the definition of a lock, whether it is intended
>   to be used recursive or not, while a mixture of both usage variants
>   needs to be
> 
> - in production builds (builds without CONFIG_DEBUG_LOCKS) the needed
>   data size of an ordinary spinlock is 8 bytes instead of 4, due to the
>   additional recursion data needed (associated with that the rwlock
>   data is using 12 instead of only 8 bytes)
> 
> Fix that by introducing a struct spinlock_recursive for recursive
> spinlocks only, and switch recursive spinlock functions to require
> pointers to this new struct.
> 
> This allows to check the correct usage at build time.
> 
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>