The patch titled
Subject: mm, thp: allow fallback when pte_alloc_one() fails for huge pmd
has been added to the -mm tree. Its filename is
mm-thp-allow-fallback-when-pte_alloc_one-fails-for-huge-pmd.patch
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------------------------------------------------------
From: David Rientjes <rientjes@xxxxxxxxxx>
Subject: mm, thp: allow fallback when pte_alloc_one() fails for huge pmd
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@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff -puN mm/huge_memory.c~mm-thp-allow-fallback-when-pte_alloc_one-fails-for-huge-pmd mm/huge_memory.c
--- a/mm/huge_memory.c~mm-thp-allow-fallback-when-pte_alloc_one-fails-for-huge-pmd
+++ a/mm/huge_memory.c
@@ -640,11 +640,8 @@ static int __do_huge_pmd_anonymous_page(
VM_BUG_ON(!PageCompound(page));
pgtable = pte_alloc_one(mm, haddr);
- if (unlikely(!pgtable)) {
- mem_cgroup_uncharge_page(page);
- put_page(page);
+ if (unlikely(!pgtable))
return VM_FAULT_OOM;
- }
clear_huge_page(page, haddr, HPAGE_PMD_NR);
__SetPageUptodate(page);
@@ -723,8 +720,14 @@ int do_huge_pmd_anonymous_page(struct mm
put_page(page);
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:
/*
_
Subject: Subject: mm, thp: allow fallback when pte_alloc_one() fails for huge pmd
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
origin.patch
linux-next.patch
mm-memory_failure-let-the-compiler-add-the-function-name.patch
mm-mempolicyc-use-enum-value-mpol_rebind_once-instead-of-0-in-mpol_rebind_policy.patch
mm-hugetlbc-cleanup-to-use-long-vars-instead-of-int-in-region_count.patch
mm-thp-remove-unnecessary-ret-variable.patch
mm-thp-allow-fallback-when-pte_alloc_one-fails-for-huge-pmd.patch
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