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mm, thp: allow fallback when pte_alloc_one() fails for huge pmd

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The transparent hugepages feature is careful to not invoke the oom
killer when a hugepage cannot be allocated.

pte_alloc_one() failing in __do_huge_pmd_anonymous_page(), however,
currently results in VM_FAULT_OOM which invokes the pagefault oom killer
to kill a memory-hogging task.

This is unnecessary since it's possible to drop the reference to the
hugepage and fallback to allocating a small page.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Rientjes
2012-05-29 15:06:17 -07:00
committed by Linus Torvalds
parent aa2e878efa
commit edad9d2c33
1 changed files with 8 additions and 5 deletions
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13
mm/huge_memory.c
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@@ -640,11 +640,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
VM_BUG_ON(!PageCompound(page)); VM_BUG_ON(!PageCompound(page));
pgtable = pte_alloc_one(mm, haddr); pgtable = pte_alloc_one(mm, haddr);
if (unlikely(!pgtable)) { if (unlikely(!pgtable))
mem_cgroup_uncharge_page(page);
put_page(page);
return VM_FAULT_OOM; return VM_FAULT_OOM;
}
clear_huge_page(page, haddr, HPAGE_PMD_NR); clear_huge_page(page, haddr, HPAGE_PMD_NR);
__SetPageUptodate(page); __SetPageUptodate(page);
@@ -723,8 +720,14 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
put_page(page); put_page(page);
goto out; goto out;
} }
if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd,
page))) {
mem_cgroup_uncharge_page(page);
put_page(page);
goto out;
}
return __do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page); return 0;
} }
out: out:
/* /*