Messages in this thread | | | Date | Fri, 21 Aug 2020 18:37:25 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/1] mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary |
| |
again, don't really understand...
On 08/21, Suren Baghdasaryan wrote: > > Actually, reviewing again and considering where list_add_tail_rcu is > happening, maybe the race with clone(CLONE_VM) does not introduce > false negatives.
I think it does... Whatever we check, mm_users or MMF_PROC_SHARED, the task can do clone(CLONE_VM) right after the check.
> However a false negative I think will happen when a > task shares mm with another task and also has an additional thread. > Shared mm will increment mm_users without adding to signal->live
Yes,
> and > the additional thread will advance signal->live without adding to > mm_users.
No, please note that CLONE_THREAD requires CLONE_VM.
Oleg.
| |