[PATCH] mm: replace is_zero_pfn with is_huge_zero_pmd for thp

From: Yu Zhao <yuzhao@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Matthew Wilcox" <willy@infradead.org>,
	"Ralph Campbell" <rcampbell@nvidia.com>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	"Will Deacon" <will@kernel.org>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
	"Dave Airlie" <airlied@redhat.com>,
	"Thomas Hellstrom" <thellstrom@vmware.com>,
	"Souptick Joarder" <jrdr.linux@gmail.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"Yu Zhao" <yuzhao@google.com>
Subject: [PATCH] mm: replace is_zero_pfn with is_huge_zero_pmd for thp
Date: Sun, 25 Aug 2019 14:06:21 -0600	[thread overview]
Message-ID: <20190825200621.211494-1-yuzhao@google.com> (raw)

For hugely mapped thp, we use is_huge_zero_pmd() to check if it's
zero page or not.

We do fill ptes with my_zero_pfn() when we split zero thp pmd, but
 this is not what we have in vm_normal_page_pmd().
pmd_trans_huge_lock() makes sure of it.

This is a trivial fix for /proc/pid/numa_maps, and AFAIK nobody
complains about it.

Signed-off-by: Yu Zhao <yuzhao@google.com>
---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory.c b/mm/memory.c
index e2bb51b6242e..ea3c74855b23 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -654,7 +654,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 
 	if (pmd_devmap(pmd))
 		return NULL;
-	if (is_zero_pfn(pfn))
+	if (is_huge_zero_pmd(pmd))
 		return NULL;
 	if (unlikely(pfn > highest_memmap_pfn))
 		return NULL;
-- 
2.23.0.187.g17f5b7556c-goog


