22 Aug
2022
22 Aug
'22
11:16 p.m.
On Mon, 22 Aug 2022 16:59:29 -0600 Yu Zhao yuzhao@google.com wrote:
@@ -4109,7 +4109,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long start, unsigned long end,
walk_pmd_range(&val, addr, next, args);
if (mm_is_oom_victim(args->mm))
if (test_bit(MMF_OOM_REAP_QUEUED, &args->mm->flags)) return 1; /* a racy check to curtail the waiting time */Oh. Why? What does this change do?
The MMF_OOM_REAP_QUEUED flag is similar to the deleted MMF_OOM_VICTIM flag, but it's set at a later stage during an OOM kill.
When either is set, the OOM reaper is probably already freeing the memory of this mm_struct, or at least it's going to. So there is no need to dwell on it in the reclaim path, hence not about correctness.
Thanks. That sounds worthy of some code comments?