On Tue, 19 Sep 2017, Yang Shi wrote:
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -35,6 +35,8 @@
> static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
> slab_caches_to_rcu_destroy_workfn);
>
> +#define K(x) ((x)/1024)
> +
> /*
> * Set of flags that will prevent slab merging
> */
> @@ -1272,6 +1274,34 @@ static int slab_show(struct seq_file *m, void *p)
> return 0;
> }
>
> +void show_unreclaimable_slab()
> +{
> + struct kmem_cache *s = NULL;
> + struct slabinfo sinfo;
> +
> + memset(&sinfo, 0, sizeof(sinfo));
> +
> + printk("Unreclaimable slabs:\n");
> +
> + /*
> + * Here acquiring slab_mutex is unnecessary since we don't prefer to
> + * get sleep in oom path right before kernel panic, and avoid race
> condition.
> + * Since it is already oom, so there should be not any big allocation
> + * which could change the statistics significantly.
> + */
> + list_for_each_entry(s, &slab_caches, list) {
> + if (!is_root_cache(s))
> + continue;
> +
> + get_slabinfo(s, &sinfo);
> +
> + if (!is_reclaimable(s) && sinfo.num_objs > 0)
> + printk("%-17s %luKB\n", cache_name(s), K(sinfo.num_objs
> * s->size));
> + }
I like this, but could we be even more helpful by giving the user more
information from sinfo beyond just the total size of objects allocated?
