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author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2016-02-03 01:57:26 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-03 17:28:43 +0100 |
commit | 5c2ff95e41c9290d16556cd02e35b25d81be8fe0 (patch) | |
tree | b2839537e7b850417f51c318503a504818f9b56d /fs/proc/task_mmu.c | |
parent | MAINTAINERS: update Seth email (diff) | |
download | linux-5c2ff95e41c9290d16556cd02e35b25d81be8fe0.tar.xz linux-5c2ff95e41c9290d16556cd02e35b25d81be8fe0.zip |
numa: fix /proc/<pid>/numa_maps for hugetlbfs on s390
When working with hugetlbfs ptes (which are actually pmds) is not valid to
directly use pte functions like pte_present() because the hardware bit
layout of pmds and ptes can be different. This is the case on s390.
Therefore we have to convert the hugetlbfs ptes first into a valid pte
encoding with huge_ptep_get().
Currently the /proc/<pid>/numa_maps code uses hugetlbfs ptes without
huge_ptep_get(). On s390 this leads to the following two problems:
1) The pte_present() function returns false (instead of true) for
PROT_NONE hugetlb ptes. Therefore PROT_NONE vmas are missing
completely in the "numa_maps" output.
2) The pte_dirty() function always returns false for all hugetlb ptes.
Therefore these pages are reported as "mapped=xxx" instead of
"dirty=xxx".
Therefore use huge_ptep_get() to correctly convert the hugetlb ptes.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: <stable@vger.kernel.org> [4.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/task_mmu.c')
-rw-r--r-- | fs/proc/task_mmu.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 85d16c67c33e..4a0c31f904a6 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1552,18 +1552,19 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr, static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { + pte_t huge_pte = huge_ptep_get(pte); struct numa_maps *md; struct page *page; - if (!pte_present(*pte)) + if (!pte_present(huge_pte)) return 0; - page = pte_page(*pte); + page = pte_page(huge_pte); if (!page) return 0; md = walk->private; - gather_stats(page, md, pte_dirty(*pte), 1); + gather_stats(page, md, pte_dirty(huge_pte), 1); return 0; } |