Re: [patch] mm, oom: prevent soft lockup on memcg oom for UP systems

[Tetsuo Handa]

On 2020/03/11 6:39, David Rientjes wrote:
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -2637,6 +2637,8 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc)
>  		unsigned long reclaimed;
>  		unsigned long scanned;
>  
> +		cond_resched();
> +

Is this safe for CONFIG_PREEMPTION case? If current thread has realtime priority,
can we guarantee that the OOM victim (well, the OOM reaper kernel thread rather
than the OOM victim ?) gets scheduled?

>  		switch (mem_cgroup_protected(target_memcg, memcg)) {
>  		case MEMCG_PROT_MIN:
>  			/*
>