Re: [PATCH mm] mm: fix BUG with kvzalloc+GFP_ATOMIC

[Florian Westphal]

Michal Hocko <mhocko@xxxxxxxx> wrote:
> +		old_tbl = rht_dereference_rcu(ht->tbl, ht);
> +		size = tbl->size;
> +
> +		data = ERR_PTR(-EBUSY);
> +
> +		if (rht_grow_above_75(ht, tbl))
> +			size *= 2;
> +		/* Do not schedule more than one rehash */
> +		else if (old_tbl != tbl)
> +			return data;
> +
> +		data = ERR_PTR(-ENOMEM);
> +
> +		rcu_read_unlock();
> +		new_tbl = bucket_table_alloc(ht, size, GFP_KERNEL);
> +		rcu_read_lock();

I don't think this is going to work, there can be callers that
rely on rcu protected data structures getting free'd.

Also, network stack assumes synchronize_rcu() means that all
inflight packets have completed processing.