On Thu, Oct 07, 2021 at 11:19:14AM -0700, Mike Kravetz wrote:
> +static ssize_t demote_store(struct kobject *kobj,
> + struct kobj_attribute *attr, const char *buf, size_t len)
> +{
> + unsigned long nr_demote;
> + unsigned long nr_available;
> + nodemask_t nodes_allowed, *n_mask;
> + struct hstate *h;
> + int err = 0;
> + int nid;
> +
> + err = kstrtoul(buf, 10, &nr_demote);
> + if (err)
> + return err;
> + h = kobj_to_hstate(kobj, &nid);
> +
> + /* Synchronize with other sysfs operations modifying huge pages */
> + mutex_lock(&h->resize_lock);
> +
> + if (nid != NUMA_NO_NODE) {
> + init_nodemask_of_node(&nodes_allowed, nid);
> + n_mask = &nodes_allowed;
> + } else {
> + n_mask = &node_states[N_MEMORY];
> + }
Why this needs to be protected by the resize_lock? I do not understand
what are we really protecting here and from what.
Besides that, I did not spot anything wrong.
--
Oscar Salvador
SUSE Labs
