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| author | Yu Zhao <yuzhao@google.com> | 2019-12-05 01:49:56 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-05 04:44:11 +0100 |
| commit | 3cde287bb4769fe9dfc9c532ddc88d90e81bc4c5 (patch) | |
| tree | ac0df3a278ac4e6c6ac54e4a48df24599379a352 /mm/memory.c | |
| parent | mm/memcontrol: use vmstat names for printing statistics (diff) | |
| download | linux-3cde287bb4769fe9dfc9c532ddc88d90e81bc4c5.tar.xz linux-3cde287bb4769fe9dfc9c532ddc88d90e81bc4c5.zip | |
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 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 2 |
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; |