From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> 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_active_list goes crazy: kernel BUG at /home/space/kas/git/public/linux-next/mm/vmscan.c:1122! invalid opcode: 0000 [#1] SMP CPU 0 Pid: 293, comm: kswapd0 Not tainted 3.8.0-rc6-next-20130202+ #531 RIP: 0010:[<ffffffff81110478>] [<ffffffff81110478>] isolate_lru_pages.isra.61+0x138/0x260 RSP: 0000:ffff8800796d9b28 EFLAGS: 00010082 RAX: 00000000ffffffea RBX: 0000000000000012 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea0001de8040 RBP: ffff8800796d9b88 R08: ffff8800796d9df0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000012 R13: ffffea0001de8060 R14: ffffffff818818e8 R15: ffff8800796d9bf8 FS: 0000000000000000(0000) GS:ffff88007a200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1bfc108000 CR3: 000000000180b000 CR4: 00000000000406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kswapd0 (pid: 293, threadinfo ffff8800796d8000, task ffff880079e0a6e0) Stack: ffff8800796d9b48 ffffffff81881880 ffff8800796d9df0 ffff8800796d9be0 0000000000000002 000000000000001f ffff8800796d9b88 ffffffff818818c8 ffffffff81881480 ffff8800796d9dc0 0000000000000002 000000000000001f Call Trace: [<ffffffff81111e98>] shrink_inactive_list+0x108/0x4a0 [<ffffffff8109ce3d>] ? trace_hardirqs_off+0xd/0x10 [<ffffffff8107b8bf>] ? local_clock+0x4f/0x60 [<ffffffff8110ff5d>] ? shrink_slab+0x1fd/0x4c0 [<ffffffff811125a1>] shrink_zone+0x371/0x610 [<ffffffff8110ff75>] ? shrink_slab+0x215/0x4c0 [<ffffffff81112dfc>] kswapd+0x5bc/0xb60 [<ffffffff81112840>] ? shrink_zone+0x610/0x610 [<ffffffff81066676>] kthread+0xd6/0xe0 [<ffffffff810665a0>] ? __kthread_bind+0x40/0x40 [<ffffffff814fed6c>] ret_from_fork+0x7c/0xb0 [<ffffffff810665a0>] ? __kthread_bind+0x40/0x40 Code: 1f 40 00 49 8b 45 08 49 8b 75 00 48 89 46 08 48 89 30 49 8b 06 4c 89 68 08 49 89 45 00 4d 89 75 08 4d 89 2e eb 9c 0f 1f 44 00 00 <0f> 0b 66 0f 1f 44 00 00 31 db 45 31 e4 eb 9b 0f 0b 0f 0b 65 48 RIP [<ffffffff81110478>] isolate_lru_pages.isra.61+0x138/0x260 RSP <ffff8800796d9b28> 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@xxxxxxxxxxxxxxx> --- mm/huge_memory.c | 4 +++- mm/swap.c | 20 ++------------------ 2 files changed, 5 insertions(+), 19 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 03a89a2..b39fa01 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1612,7 +1612,9 @@ static void __split_huge_page_refcount(struct page *page, ((1L << PG_referenced) | (1L << PG_swapbacked) | (1L << PG_mlocked) | - (1L << PG_uptodate))); + (1L << PG_uptodate) | + (1L << PG_active) | + (1L << PG_unevictable))); page_tail->flags |= (1L << PG_dirty); /* clear PageTail before overwriting first_page */ diff --git a/mm/swap.c b/mm/swap.c index acd40bf..9b0a64b 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -739,8 +739,6 @@ 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)); @@ -752,20 +750,6 @@ 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) { @@ -781,13 +765,13 @@ 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 */ -- 1.7.10.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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