Re: [PATCH memcg] memcg: prohibit unconditional exceeding the limit of dying tasks
From: Vasily Averin <hidden>
Date: 2021-09-13 07:51:44
Also in:
linux-mm, lkml
On 9/10/21 3:39 PM, Vasily Averin wrote:
The kernel currently allows dying tasks to exceed the memcg limits. The allocation is expected to be the last one and the occupied memory will be freed soon. This is not always true because it can be part of the huge vmalloc allocation. Allowed once, they will repeat over and over again.
quoted hunk ↗ jump to hunk
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 389b5766e74f..67195fcfbddf 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c@@ -2622,15 +2625,6 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, if (gfp_mask & __GFP_ATOMIC) goto force; - /* - * Unlike in global OOM situations, memcg is not in a physical - * memory shortage. Allow dying and OOM-killed tasks to - * bypass the last charges so that they can exit quickly and - * free their memory. - */ - if (unlikely(should_force_charge())) - goto force; -
Should we keep current behaviour for (current->flags & PF_EXITING) case perhaps? It is set inside do_exit only and (I hope) cannot trigger huge vmalloc allocations. Thank you, Vasily Averin