Re: [PATCH] mm/slub: improve count_partial() for CONFIG_SLUB_CPU_PARTIAL

[Christopher Lameter]

On Mon, 24 Feb 2020, Roman Gushchin wrote:

> > I suggest that you simply use the number of partial slabs and multiply
> > them by the number of objects in a slab and use that as a value. Both
> > values are readily available via /sys/kernel/slab/<...>/
>
> So maybe something like this?
>
> @@ -5907,7 +5907,9 @@ void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
>  	for_each_kmem_cache_node(s, node, n) {
>  		nr_slabs += node_nr_slabs(n);
>  		nr_objs += node_nr_objs(n);
> +#ifndef CONFIG_SLUB_CPU_PARTIAL
>  		nr_free += count_partial(n, count_free);
> +#endif
>  	}

Why would not having cpu partials screws up the counting of objects in
partial slabs?


You dont need kernel mods for this. The numbers are exposed already in
/sys/kernel/slab/xxx.