linux-kernel - [PATCHv2 2/2] mm: downgrade VM_BUG in isolate_lru

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Date:	Tue,  2 Feb 2016 19:21:01 +0300
From:	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To:	Andrew Morton <akpm@...ux-foundation.org>,
	Dmitry Vyukov <dvyukov@...gle.com>
Cc:	Vlastimil Babka <vbabka@...e.cz>,
	David Rientjes <rientjes@...gle.com>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
	Michal Hocko <mhocko@...e.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCHv2 2/2] mm: downgrade VM_BUG in isolate_lru_page() to warning

Calling isolate_lru_page() is wrong and shouldn't happen, but it not
nessesary fatal: the page just will not be isolated if it's not on LRU.

Let's downgrade the VM_BUG_ON_PAGE() to WARN_RATELIMIT().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eb3dd37ccd7c..71b1c29948db 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1443,7 +1443,7 @@ int isolate_lru_page(struct page *page)
 	int ret = -EBUSY;
 
 	VM_BUG_ON_PAGE(!page_count(page), page);
-	VM_BUG_ON_PAGE(PageTail(page), page);
+	WARN_RATELIMIT(PageTail(page), "trying to isolate tail page");
 
 	if (PageLRU(page)) {
 		struct zone *zone = page_zone(page);
-- 
2.7.0