On Tue, May 28, 2019 at 10:54:32PM +0800, Hillf Danton wrote:
>
> On Mon, 20 May 2019 12:52:50 +0900 Minchan Kim wrote:
> > +unsigned long reclaim_pages(struct list_head *page_list)
> > +{
> > + int nid = -1;
> > + unsigned long nr_isolated[2] = {0, };
> > + unsigned long nr_reclaimed = 0;
> > + LIST_HEAD(node_page_list);
> > + struct reclaim_stat dummy_stat;
> > + struct scan_control sc = {
> > + .gfp_mask = GFP_KERNEL,
> > + .priority = DEF_PRIORITY,
> > + .may_writepage = 1,
> > + .may_unmap = 1,
> > + .may_swap = 1,
> > + };
> > +
> > + while (!list_empty(page_list)) {
> > + struct page *page;
> > +
> > + page = lru_to_page(page_list);
> > + list_del(&page->lru);
> > +
> > + if (nid == -1) {
> > + nid = page_to_nid(page);
> > + INIT_LIST_HEAD(&node_page_list);
> > + nr_isolated[0] = nr_isolated[1] = 0;
> > + }
> > +
> > + if (nid == page_to_nid(page)) {
> > + list_add(&page->lru, &node_page_list);
> > + nr_isolated[!!page_is_file_cache(page)] +=
> > + hpage_nr_pages(page);
> > + continue;
> > + }
> > +
> Now, page's node != nid and any page on the node_page_list has
> node == nid.
> > + nid = page_to_nid(page);
>
> After updating nid, we get the node id of the isolated pages lost.
>
> > +
> > + mod_node_page_state(NODE_DATA(nid), NR_ISOLATED_ANON,
> > + nr_isolated[0]);
> > + mod_node_page_state(NODE_DATA(nid), NR_ISOLATED_FILE,
> > + nr_isolated[1]);
> > + nr_reclaimed += shrink_page_list(&node_page_list,
> > + NODE_DATA(nid), &sc, TTU_IGNORE_ACCESS,
>
> And nid no longer matches the node of the pages to be shrunk.
>
> > + &dummy_stat, true);
> > + while (!list_empty(&node_page_list)) {
> > + struct page *page = lru_to_page(page_list);
>
> Non-empty node_page_list will never become empty if pages are deleted
> only from the page_list.
Sure.
They were last minute change. I will fix it.
Thanks for the review!
