Re: [PATCH] slub: fix __kmem_cache_empty for !CONFIG_SLUB_DEBUG

[Andrey Ryabinin]

On 06/20/2018 12:33 AM, Shakeel Butt wrote:
> For !CONFIG_SLUB_DEBUG, SLUB does not maintain the number of slabs
> allocated per node for a kmem_cache. Thus, slabs_node() in
> __kmem_cache_empty() will always return 0. So, in such situation, it is
> required to check per-cpu slabs to make sure if a kmem_cache is empty or
> not.
> 
> Please note that __kmem_cache_shutdown() and __kmem_cache_shrink() are
> not affected by !CONFIG_SLUB_DEBUG as they call flush_all() to clear
> per-cpu slabs.

So what? Yes, they call flush_all() and then check if there are non-empty slabs left.
And that check doesn't work in case of disabled CONFIG_SLUB_DEBUG.
How is flush_all() or per-cpu slabs even relevant here?