On Fri, Jul 19, 2013 at 10:39 PM, Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> wrote: > On Fri, Jul 19, 2013 at 01:40:38PM +0800, Hillf Danton wrote: >> On Fri, Jul 19, 2013 at 5:34 AM, Naoya Horiguchi >> <n-horiguchi@xxxxxxxxxxxxx> wrote: >> > @@ -518,9 +519,11 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid) >> > { >> > struct page *page; >> > >> > - if (list_empty(&h->hugepage_freelists[nid])) >> > + list_for_each_entry(page, &h->hugepage_freelists[nid], lru) >> > + if (!is_migrate_isolate_page(page)) >> > + break; >> > + if (&h->hugepage_freelists[nid] == &page->lru) >> >> For what is this check? > > This check returns true unless a non-isolated free hugepage is found. > In "not found" case page points to h->hugepage_freelists, so without > this check successive code doesn't work fine. > Thanks for your explanation, and looks another local variable struct page *found for easing reader. Good weekend Hillf -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>