On 2/14/24 23:04, Zi Yan wrote:
> @@ -1849,10 +1857,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
> static void compaction_free(struct folio *dst, unsigned long data)
> {
> struct compact_control *cc = (struct compact_control *)data;
> + int order = folio_order(dst);
> + struct page *page = &dst->page;
> +
> + if (folio_put_testzero(dst)) {
> + free_pages_prepare_fpi_none(page, order);
> +
> + INIT_LIST_HEAD(&dst->lru);
(is this even needed? I think the state of first parameter of list_add() is
never expected to be in particular state?)
>
> - list_add(&dst->lru, &cc->freepages);
> - cc->nr_freepages++;
> - cc->nr_migratepages += 1 << folio_order(dst);
> + list_add(&dst->lru, &cc->freepages[order]);
> + cc->nr_freepages += 1 << order;
> + cc->nr_migratepages += 1 << order;
Hm actually this increment of nr_migratepages should happen even if we lost
the free page.
> + }
> + /*
> + * someone else has referenced the page, we cannot take it back to our
> + * free list.
> + */
> }
