Re: [PATCH v2] mm/shrinker: Fix refcount leak in shrink_slab_memcg()

[Muchun Song]

> On Feb 4, 2026, at 11:35, Altan Hacigumus <ahacigu.linux@xxxxxxxxx> wrote:
> 
> When kmem is disabled for memcg, slab-backed shrinkers are skipped.
> However, shrink_slab_memcg() doesn't drop the reference acquired via
> shrinker_try_get() before continuing.
> 
> Add the missing shrinker_put().
> 
> Also, since memcg_kmem_online() and shrinker flags cannot change
> dynamically, remove the shrinker from the bitmap to avoid unnecessary
> future scans.
> 
> Fixes: 50d09da8e119 ("mm: shrinker: make memcg slab shrink lockless")
> Suggested-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Acked-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20260203073757.135088-1-ahacigu.linux@xxxxxxxxx
> Signed-off-by: Altan Hacigumus <ahacigu.linux@xxxxxxxxx>

Reviewed-by: Muchun Song <muchun.song@xxxxxxxxx>