On Wed 22-11-23 18:25:09, Kent Overstreet wrote:
[...]
> 00177 Shrinkers:
> 00177 super_cache_scan: objects: 127
> 00177 super_cache_scan: objects: 106
> 00177 jbd2_journal_shrink_scan: objects: 32
> 00177 ext4_es_scan: objects: 32
> 00177 bch2_btree_cache_scan: objects: 8
> 00177 nr nodes: 24
> 00177 nr dirty: 0
> 00177 cannibalize lock: 0000000000000000
> 00177
> 00177 super_cache_scan: objects: 8
> 00177 super_cache_scan: objects: 1
It would be really great to provide an example on how these numbers are
useful for the oom evaluation.
[...]
> @@ -423,4 +426,21 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
> #ifdef CONFIG_MEMORY_FAILURE
> printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages));
> #endif
> +
> + buf = kmalloc(4096, GFP_ATOMIC);
I really do not think we want to allow allocations from the OOM context.
Is there any reason why this cannot be a statically allocated buffer?
> + if (buf) {
> + struct seq_buf s;
> +
> + printk("Unreclaimable slab info:\n");
> + seq_buf_init(&s, buf, 4096);
> + dump_unreclaimable_slab(&s);
> + printk("%s", seq_buf_str(&s));
> +
> + printk("Shrinkers:\n");
> + seq_buf_init(&s, buf, 4096);
> + shrinkers_to_text(&s);
> + printk("%s", seq_buf_str(&s));
> +
> + kfree(buf);
> + }
> }
--
Michal Hocko
SUSE Labs
