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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-04-07 14:26:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-07 16:45:33 -0700
commit6b79c57b92cdd90853002980609af516d14c4f9c (patch)
tree2b209795920c9311d8638b6f442224e0aa7995a0 /kernel/sched
parentce66b032ad7b838bf376e3b1bb4d8bce1a69ee5c (diff)
downloadblackbird-op-linux-6b79c57b92cdd90853002980609af516d14c4f9c.tar.gz
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mm: numa: disable change protection for vma(VM_HUGETLB)
Currently when a process accesses a hugetlb range protected with PROTNONE, unexpected COWs are triggered, which finally puts the hugetlb subsystem into a broken/uncontrollable state, where for example h->resv_huge_pages is subtracted too much and wraps around to a very large number, and the free hugepage pool is no longer maintainable. This patch simply stops changing protection for vma(VM_HUGETLB) to fix the problem. And this also allows us to avoid useless overhead of minor faults. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Suggested-by: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/fair.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index bcfe32088b37..241213be507c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2165,8 +2165,10 @@ void task_numa_work(struct callback_head *work)
vma = mm->mmap;
}
for (; vma; vma = vma->vm_next) {
- if (!vma_migratable(vma) || !vma_policy_mof(vma))
+ if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
+ is_vm_hugetlb_page(vma)) {
continue;
+ }
/*
* Shared library pages mapped by multiple processes are not
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