<alexlzhu@xxxxxx> writes:
[snip]
> +static void thp_util_scan(unsigned long pfn_end)
> +{
> + struct page *page = NULL;
> + int bucket, current_pfn, num_utilized_pages;
> + int i;
> + /*
> + * Scan through each memory zone in chunks of THP_UTIL_SCAN_SIZE
> + * PFNs every second looking for anonymous THPs.
> + */
> + for (i = 0; i < THP_UTIL_SCAN_SIZE; i++) {
> + current_pfn = thp_scan.pfn;
> + thp_scan.pfn += HPAGE_PMD_NR;
> + if (current_pfn >= pfn_end)
> + return;
> +
> + page = pfn_to_online_page(current_pfn);
> + if (!page)
> + continue;
If my understanding were correct, the page may be offlined during
pfn_to_online_page() and the following code. So we need to call
get/put_online_mems().
If my understanding were incorrect, can anyone teach me on this?
> +
> + num_utilized_pages = thp_number_utilized_pages(page_folio(page));
> + bucket = thp_utilization_bucket(num_utilized_pages);
> + if (bucket < 0)
> + continue;
> +
> + thp_scan.buckets[bucket].nr_thps++;
> + thp_scan.buckets[bucket].nr_zero_pages += (HPAGE_PMD_NR - num_utilized_pages);
> + }
> +}
> +
Best Regards,
Huang, Ying
