Re: [PATCH v2] memcg: allow exiting tasks to write back data to swap

[Rik van Riel <riel@surriel.com>]

On Tue, 2025-01-14 at 17:54 +0100, Michal Hocko wrote:
> O
> Btw. is there any actual reason why we cannot go nomem without going
> to the oom killer (just to bail out) and go through the whole cycle
> again? That seems arbitrary and simply burning a lot of cycle without
> much chances to make any better outcome
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 7b3503d12aaf..eb45eaf0acfc 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2268,8 +2268,7 @@ int try_charge_memcg(struct mem_cgroup *memcg,
> gfp_t gfp_mask,
>  	if (gfp_mask & __GFP_RETRY_MAYFAIL)
>  		goto nomem;
>  
> -	/* Avoid endless loop for tasks bypassed by the oom killer
> */
> -	if (passed_oom && task_is_dying())
> +	if (task_is_dying())
>  		goto nomem;
>  
>  	/*

When we return from the page fault handler, we
restart the instruction that faulted.

That means we could just end up repeating the
same fault over and over again.

-- 
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