path: root/mm/memory.c
diff options
authorYu Zhao <yuzhao@google.com>2019-12-04 16:49:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-04 19:44:11 -0800
commit3cde287bb4769fe9dfc9c532ddc88d90e81bc4c5 (patch)
treeac0df3a278ac4e6c6ac54e4a48df24599379a352 /mm/memory.c
parentmm/memcontrol: use vmstat names for printing statistics (diff)
mm/memory.c: replace is_zero_pfn with is_huge_zero_pmd for thp
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. Gerald Schaefer asked: : Maybe the description could also mention the symptom of this bug? : I would assume that it affects anon/dirty accounting in gather_pte_stats(), : for huge mappings, if zero page mappings are not correctly recognized. I came across this while I was looking at the code, so I'm not aware of any symptom. Link: http://lkml.kernel.org/r/20191108192629.201556-1-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Will Deacon <will@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 513c3ecc76ee..e455160e0f75 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -672,7 +672,7 @@ 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;