Re: [patch 19/25] debugobjects: Prepare for batching

["Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>]

On 2024/10/8 0:50, Thomas Gleixner wrote:
> Move the debug_obj::object pointer into a union and add a pointer to the
> last node in a batch. That allows to implement batch processing efficiently
> by utilizing the stack property of hlist:
> 
> When the first object of a batch is added to the list, then the batch
> pointer is set to the hlist node of the object itself. Any subsequent add
> retrieves the pointer to the last node from the first object in the list
> and uses that for storing the last node pointer in the newly added object.
> 
> Add the pointer to the data structure and ensure that all relevant pool
> sizes are strictly batch sized. The actual batching implementation follows
> in subsequent changes.

Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>

> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  include/linux/debugobjects.h |   12 ++++++++----
>  lib/debugobjects.c           |   10 +++++++---
>  2 files changed, 15 insertions(+), 7 deletions(-)
> 
> --- a/include/linux/debugobjects.h
> +++ b/include/linux/debugobjects.h
> @@ -23,13 +23,17 @@ struct debug_obj_descr;
>   * @state:	tracked object state
>   * @astate:	current active state
>   * @object:	pointer to the real object
> + * @batch_last:	pointer to the last hlist node in a batch
>   * @descr:	pointer to an object type specific debug description structure
>   */
>  struct debug_obj {
> -	struct hlist_node	node;
> -	enum debug_obj_state	state;
> -	unsigned int		astate;
> -	void			*object;
> +	struct hlist_node		node;
> +	enum debug_obj_state		state;
> +	unsigned int			astate;
> +	union {
> +		void			*object;
> +		struct hlist_node	*batch_last;
> +	};
>  	const struct debug_obj_descr *descr;
>  };
>  
> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -21,11 +21,15 @@
>  #define ODEBUG_HASH_BITS	14
>  #define ODEBUG_HASH_SIZE	(1 << ODEBUG_HASH_BITS)
>  
> -#define ODEBUG_POOL_SIZE	1024
> -#define ODEBUG_POOL_MIN_LEVEL	256
> -#define ODEBUG_POOL_PERCPU_SIZE	64
> +/* Must be power of two */
>  #define ODEBUG_BATCH_SIZE	16
>  
> +/* Initial values. Must all be a multiple of batch size */
> +#define ODEBUG_POOL_SIZE	(64 * ODEBUG_BATCH_SIZE)
> +#define ODEBUG_POOL_MIN_LEVEL	(ODEBUG_POOL_SIZE / 4)
> +
> +#define ODEBUG_POOL_PERCPU_SIZE	(4 * ODEBUG_BATCH_SIZE)
> +
>  #define ODEBUG_CHUNK_SHIFT	PAGE_SHIFT
>  #define ODEBUG_CHUNK_SIZE	(1 << ODEBUG_CHUNK_SHIFT)
>  #define ODEBUG_CHUNK_MASK	(~(ODEBUG_CHUNK_SIZE - 1))
> 
> .
> 

-- 
Regards,
  Zhen Lei