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@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>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8ab2d24..d7d7165 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -640,11 +640,8 @@
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 @@
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:
/*