Re: [patch 23/25] debugobjects: Double the per CPU slots

[Leizhen (ThunderTown)]

On 2024/10/8 0:50, Thomas Gleixner wrote:
> In situations where objects are rapidly allocated from the pool and handed
> back, the size of the per CPU pool turns out to be too small.
> 
> Double the size of the per CPU pool.
> 
> This reduces the kmem cache allocation and free operations during a kernel compile:
> 
>      	     alloc    	    free
> Baseline:    380k           330k
> Double size: 295k	    245k
> 
> Especially the reduction of allocations is important because that happens
> in the hot path when objects are initialized.
> 
> The maximum increase in per CPU pool memory consumption is about 2.5K per
> online CPU, which is acceptable.

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

> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
>  lib/debugobjects.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -28,7 +28,7 @@
>  #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_POOL_PERCPU_SIZE	(8 * ODEBUG_BATCH_SIZE)
>  
>  #define ODEBUG_CHUNK_SHIFT	PAGE_SHIFT
>  #define ODEBUG_CHUNK_SIZE	(1 << ODEBUG_CHUNK_SHIFT)
> 
> .
> 

-- 
Regards,
  Zhen Lei