When handling a fault in an mshare range, redirect charges for page
tables and other allocations to the mshare owner rather than the
current task.
Signed-off-by: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>
---
mm/memory.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/mm/memory.c b/mm/memory.c
index 177eb53475cb..127db0b9932c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -6468,9 +6468,17 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
struct mm_struct *mm = vma->vm_mm;
vm_fault_t ret;
bool is_droppable;
+ bool is_mshare = mm_flags_test(MMF_MSHARE, mm);
+ struct mem_cgroup *mshare_memcg;
+ struct mem_cgroup *memcg;
__set_current_state(TASK_RUNNING);
+ if (unlikely(is_mshare)) {
+ mshare_memcg = get_mem_cgroup_from_mm(vma->vm_mm);
+ memcg = set_active_memcg(mshare_memcg);
+ }
+
ret = sanitize_fault_flags(vma, &flags);
if (ret)
goto out;
@@ -6530,6 +6538,11 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
out:
mm_account_fault(mm, regs, address, flags, ret);
+ if (unlikely(is_mshare)) {
+ set_active_memcg(memcg);
+ mem_cgroup_put(mshare_memcg);
+ }
+
return ret;
}
EXPORT_SYMBOL_GPL(handle_mm_fault);
--
2.47.1
