4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Rientjes <[email protected]> [ Upstream commit 9d3c3354bb85bab4d865fe95039443f09a4c8394 ] Commit 2516035499b9 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations") changed the page allocator to no longer detect thp allocations based on __GFP_NORETRY. It did not, however, modify the mem cgroup try_charge() path to avoid oom kill for either khugepaged collapsing or thp faulting. It is never expected to oom kill a process to allocate a hugepage for thp; reclaim is governed by the thp defrag mode and MADV_HUGEPAGE, but allocations (and charging) should fallback instead of oom killing processes. Link: http://lkml.kernel.org/r/[email protected] Fixes: 2516035499b9 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations") Signed-off-by: David Rientjes <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Johannes Weiner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/huge_memory.c | 5 +++-- mm/khugepaged.c | 8 ++++++-- 2 files changed, 9 insertions(+), 4 deletions(-) --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -555,7 +555,8 @@ static int __do_huge_pmd_anonymous_page( VM_BUG_ON_PAGE(!PageCompound(page), page); - if (mem_cgroup_try_charge(page, vma->vm_mm, gfp, &memcg, true)) { + if (mem_cgroup_try_charge(page, vma->vm_mm, gfp | __GFP_NORETRY, &memcg, + true)) { put_page(page); count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; @@ -1304,7 +1305,7 @@ alloc: } if (unlikely(mem_cgroup_try_charge(new_page, vma->vm_mm, - huge_gfp, &memcg, true))) { + huge_gfp | __GFP_NORETRY, &memcg, true))) { put_page(new_page); split_huge_pmd(vma, vmf->pmd, vmf->address); if (page) --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -965,7 +965,9 @@ static void collapse_huge_page(struct mm goto out_nolock; } - if (unlikely(mem_cgroup_try_charge(new_page, mm, gfp, &memcg, true))) { + /* Do not oom kill for khugepaged charges */ + if (unlikely(mem_cgroup_try_charge(new_page, mm, gfp | __GFP_NORETRY, + &memcg, true))) { result = SCAN_CGROUP_CHARGE_FAIL; goto out_nolock; } @@ -1324,7 +1326,9 @@ static void collapse_shmem(struct mm_str goto out; } - if (unlikely(mem_cgroup_try_charge(new_page, mm, gfp, &memcg, true))) { + /* Do not oom kill for khugepaged charges */ + if (unlikely(mem_cgroup_try_charge(new_page, mm, gfp | __GFP_NORETRY, + &memcg, true))) { result = SCAN_CGROUP_CHARGE_FAIL; goto out; }
