Re: [PATCH] mm: memcontrol: Set the correct memcg swappiness restriction

[Vlastimil Babka]

On 7/30/21 8:39 AM, Michal Hocko wrote:
> On Fri 30-07-21 14:26:35, Baolin Wang wrote:
>> Since commit c843966c556d ("mm: allow swappiness that prefers reclaiming
>> anon over the file workingset") has expended the swappiness value to
>> make swap to be preferred in some systems. We should also change the
>> memcg swappiness restriction to allow memcg swap-preferred.
>> 
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> 
> Yes, this looks like an omission. It doesn't really make sense to have
> two different constrains on the value.
> 
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>

So, also Fixes: c843966c556d ("mm: allow swappiness that prefers reclaiming anon
over the file workingset")
?

> Thanks!
> 
>> ---
>>  mm/memcontrol.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index 6580c23..988fc94 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -4046,7 +4046,7 @@ static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
>>  {
>>  	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
>>  
>> -	if (val > 100)
>> +	if (val > 200)
>>  		return -EINVAL;
>>  
>>  	if (!mem_cgroup_is_root(memcg))
>> -- 
>> 1.8.3.1
>