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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2013-07-31 13:53:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-31 14:41:03 -0700
commite180cf806a93ea1abbce47b245d25204ff557ce9 (patch)
tree5572b815fe0925f720624fb71d0d1bea81dd878b /mm/swap.c
parentef2a2cbdda7e9d084a85846770fcc844958881f6 (diff)
downloadop-kernel-dev-e180cf806a93ea1abbce47b245d25204ff557ce9.zip
op-kernel-dev-e180cf806a93ea1abbce47b245d25204ff557ce9.tar.gz
thp, mm: avoid PageUnevictable on active/inactive lru lists
active/inactive lru lists can contain unevicable pages (i.e. ramfs pages that have been placed on the LRU lists when first allocated), but these pages must not have PageUnevictable set - otherwise shrink_[in]active_list goes crazy: kernel BUG at /home/space/kas/git/public/linux-next/mm/vmscan.c:1122! 1090 static unsigned long isolate_lru_pages(unsigned long nr_to_scan, 1091 struct lruvec *lruvec, struct list_head *dst, 1092 unsigned long *nr_scanned, struct scan_control *sc, 1093 isolate_mode_t mode, enum lru_list lru) 1094 { ... 1108 switch (__isolate_lru_page(page, mode)) { 1109 case 0: ... 1116 case -EBUSY: ... 1121 default: 1122 BUG(); 1123 } 1124 } ... 1130 } __isolate_lru_page() returns EINVAL for PageUnevictable(page). For lru_add_page_tail(), it means we should not set PageUnevictable() for tail pages unless we're sure that it will go to LRU_UNEVICTABLE. Let's just copy PG_active and PG_unevictable from head page in __split_huge_page_refcount(), it will simplify lru_add_page_tail(). This will fix one more bug in lru_add_page_tail(): if page_evictable(page_tail) is false and PageLRU(page) is true, page_tail will go to the same lru as page, but nobody cares to sync page_tail active/inactive state with page. So we can end up with inactive page on active lru. The patch will fix it as well since we copy PG_active from head page. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swap.c')
-rw-r--r--mm/swap.c20
1 files changed, 2 insertions, 18 deletions
diff --git a/mm/swap.c b/mm/swap.c
index d3982c0..62b78a6 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -770,8 +770,6 @@ EXPORT_SYMBOL(__pagevec_release);
void lru_add_page_tail(struct page *page, struct page *page_tail,
struct lruvec *lruvec, struct list_head *list)
{
- int uninitialized_var(active);
- enum lru_list lru;
const int file = 0;
VM_BUG_ON(!PageHead(page));
@@ -783,20 +781,6 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
if (!list)
SetPageLRU(page_tail);
- if (page_evictable(page_tail)) {
- if (PageActive(page)) {
- SetPageActive(page_tail);
- active = 1;
- lru = LRU_ACTIVE_ANON;
- } else {
- active = 0;
- lru = LRU_INACTIVE_ANON;
- }
- } else {
- SetPageUnevictable(page_tail);
- lru = LRU_UNEVICTABLE;
- }
-
if (likely(PageLRU(page)))
list_add_tail(&page_tail->lru, &page->lru);
else if (list) {
@@ -812,13 +796,13 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
* Use the standard add function to put page_tail on the list,
* but then correct its position so they all end up in order.
*/
- add_page_to_lru_list(page_tail, lruvec, lru);
+ add_page_to_lru_list(page_tail, lruvec, page_lru(page_tail));
list_head = page_tail->lru.prev;
list_move_tail(&page_tail->lru, list_head);
}
if (!PageUnevictable(page))
- update_page_reclaim_stat(lruvec, file, active);
+ update_page_reclaim_stat(lruvec, file, PageActive(page_tail));
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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