Re: [PATCH 03/10] ttm/pool: initialise the shrinker earlier (v2)

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Mon, 2026-07-06 at 15:22 +1000, Dave Airlie wrote:
> From: Dave Airlie <airlied@redhat.com>
> 
> Later memcg enablement needs the shrinker initialised before the list
> lru,
> Just move it for now, but also handle the list being uninitialised.
> 
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> 
> ---
> v2: sashiko identified a problem with the list handling.
> ---

Couple of seemingly valid Sashiko issues:

https://sashiko.dev/#/message/20260706053333.AEABE1F000E9%40smtp.kernel.org

Thanks,
Thomas


>  drivers/gpu/drm/ttm/ttm_pool.c | 30 +++++++++++++++++-------------
>  1 file changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_pool.c
> b/drivers/gpu/drm/ttm/ttm_pool.c
> index e4dbf4c93091..f12b68812081 100644
> --- a/drivers/gpu/drm/ttm/ttm_pool.c
> +++ b/drivers/gpu/drm/ttm/ttm_pool.c
> @@ -440,10 +440,14 @@ static unsigned int ttm_pool_shrink(int nid,
> unsigned long num_to_free)
>  
>  	down_read(&pool_shrink_rwsem);
>  	spin_lock(&shrinker_lock);
> -	pt = list_first_entry(&shrinker_list, typeof(*pt),
> shrinker_list);
> -	list_move_tail(&pt->shrinker_list, &shrinker_list);
> +	pt = list_first_entry_or_null(&shrinker_list, typeof(*pt),
> shrinker_list);
> +	if (pt)
> +		list_move_tail(&pt->shrinker_list, &shrinker_list);
>  	spin_unlock(&shrinker_lock);
>  
> +	if (!pt)
> +		return 0;
> +
>  	num_pages = list_lru_walk_node(&pt->pages, nid,
> pool_move_to_dispose_list, &dispose, &num_to_free);
>  	num_pages *= 1 << pt->order;
>  
> @@ -1402,6 +1406,17 @@ int ttm_pool_mgr_init(unsigned long num_pages)
>  	spin_lock_init(&shrinker_lock);
>  	INIT_LIST_HEAD(&shrinker_list);
>  
> +	mm_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE, "drm-
> ttm_pool");
> +	if (!mm_shrinker)
> +		return -ENOMEM;
> +
> +	mm_shrinker->count_objects = ttm_pool_shrinker_count;
> +	mm_shrinker->scan_objects = ttm_pool_shrinker_scan;
> +	mm_shrinker->batch = TTM_SHRINKER_BATCH;
> +	mm_shrinker->seeks = 1;
> +
> +	shrinker_register(mm_shrinker);
> +
>  	for (i = 0; i < NR_PAGE_ORDERS; ++i) {
>  		ttm_pool_type_init(&global_write_combined[i], NULL,
>  				   ttm_write_combined, i);
> @@ -1424,17 +1439,6 @@ int ttm_pool_mgr_init(unsigned long num_pages)
>  #endif
>  #endif
>  
> -	mm_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE, "drm-
> ttm_pool");
> -	if (!mm_shrinker)
> -		return -ENOMEM;
> -
> -	mm_shrinker->count_objects = ttm_pool_shrinker_count;
> -	mm_shrinker->scan_objects = ttm_pool_shrinker_scan;
> -	mm_shrinker->batch = TTM_SHRINKER_BATCH;
> -	mm_shrinker->seeks = 1;
> -
> -	shrinker_register(mm_shrinker);
> -
>  	return 0;
>  }
>