From: Zi Yan <zi.yan@cs.rutgers.edu>
Date: Fri, 13 Oct 2017 22:57:47 +0000 (-0700)
Subject: mm: remove unnecessary WARN_ONCE in page_vma_mapped_walk().
X-Git-Tag: v4.14-rc5~13^2~12
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=af0db981f35ea99b00a0b249bf0bedef8cf972e8;p=platform%2Fkernel%2Flinux-rpi3.git

mm: remove unnecessary WARN_ONCE in page_vma_mapped_walk().

A non present pmd entry can appear after pmd_lock is taken in
page_vma_mapped_walk(), even if THP migration is not enabled.  The
WARN_ONCE is unnecessary.

Link: http://lkml.kernel.org/r/20171003142606.12324-1-zi.yan@sent.com
Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 6a03946..eb462e7 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -167,8 +167,7 @@ restart:
 						return not_found(pvmw);
 					return true;
 				}
-			} else
-				WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!");
+			}
 			return not_found(pvmw);
 		} else {
 			/* THP pmd was split under us: handle on pte level */