Messages in this thread Patch in this message | | | Date | Thu, 6 Mar 2014 17:31:12 -0500 | From | Rik van Riel <> | Subject | [PATCH -mm] mm,numa,mprotect: always continue after finding a stable thp page |
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On Thu, 06 Mar 2014 16:12:28 -0500 Sasha Levin <sasha.levin@oracle.com> wrote:
> While fuzzing with trinity inside a KVM tools guest running latest -next kernel I've hit the > following spew. This seems to be introduced by your patch "mm,numa: reorganize change_pmd_range()".
That patch should not introduce any functional changes, except for the VM_BUG_ON that catches the fact that we fell through to the 4kB pte handling code, despite having just handled a THP pmd...
Does this patch fix the issue?
Mel, am I overlooking anything obvious? :)
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Subject: mm,numa,mprotect: always continue after finding a stable thp page
When turning a thp pmds into a NUMA one, change_huge_pmd will return 0 when the pmd already is a NUMA pmd.
However, change_pmd_range would fall through to the code that handles 4kB pages, instead of continuing on to the next pmd.
Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Mel Gorman <mgorman@suse.de> --- mm/mprotect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mprotect.c b/mm/mprotect.c index 61f0a07..4746608 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -138,8 +138,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, pages += HPAGE_PMD_NR; nr_huge_updates++; } - continue; } + continue; } /* fall through, the trans huge pmd just split */ }
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